tag:blogger.com,1999:blog-39646759021151597382024-02-20T18:32:15.828-08:00Pulp, Paper, Board, Packaging and Bioleaching MicrobiologyTraditional microbiological methods, despite their important role in the selection of harmful microbes from process and product samples, does not fulfill the needs of modern HACCP and process stability control. Novel tools for mb control are therefore needed. - After retirement I have focused also on bioleaching which is a promising way to collect certain minerals from poor mining areas but has certain problems, especially in Finland.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.comBlogger77125tag:blogger.com,1999:blog-3964675902115159738.post-73781337941934175332016-08-17T00:23:00.002-07:002016-08-17T00:23:41.428-07:00What will be happened in industrial-scale bioleaching?<div style="text-align: center;">
What shall be taken into account when starting big-scale bioleaching? Some ideas:</div>
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<br /></div>
<div style="text-align: center;">
1. A successive set of bioleaching pilots (with increasing size).</div>
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2. Transport of gases (O2, CO2).</div>
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3. Nutrients (P, N etc.).</div>
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4. Temperature.</div>
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5. Risk of re-building metal sulfides.</div>
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6. Microbial reduction of sulfate (see point 5.)</div>
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7. Chemical inhibition of sulfide-oxidizing metabolism.</div>
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8. Efficiency of Fe3+ to dissolute nickel.</div>
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9. Continuous control of microbial activities.</div>
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<br /></div>
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These are the basic issues. There may be more of them.</div>
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<br /></div>
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Coming back soon...</div>
Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-31104089221460402312016-08-15T10:14:00.001-07:002016-08-15T10:14:10.969-07:00Bioleaching of Nickel - A Challenging TaskIt seems that the retirement doesn't stop any person, dedicated to her/his work, to continue actual questions of her/his profession. My wife has worked as a nurse and still dreams about her work with schoolchildren...and the interests of mine are the questions of environmental and industrial microbiology. Can't help...<br />
<br />
Bioleaching of metals from sulfide rocks is a most interesting thing! It happens in natural conditions on an area in Northern Europe where the rock contains sulfides of certain metals. Those bacteria which can perform this bioprocess are unique - they need bot oxygen and carbon dioxide as well as some other nutrients but no organic carbon source for energy at all. They are typically slow-growing microorganisms on the surface of the stone.<br />
<br />
How to maintain an industrial-scale bioleaching process in mines where the conditions can be as different as in Northern Finland (cold, moist) and Australia (warm, dry)? This is the main question which I have studied by using scientific literature and results of laboratories (as far as they are public - what they not always are, indeed!), trying to compare different cases.<br />
<br />
- More of the basics of bioleaching and cases in coming posts...keep following!Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-37619904983906934262014-12-11T23:26:00.003-08:002014-12-29T00:59:31.148-08:00The Role of Microbes in Bio Boom - Part 2.<h3 class="post-title entry-title" itemprop="name" style="background-color: #fefdfa; color: #d52a33; font-family: Georgia, Utopia, 'Palatino Linotype', Palatino, serif; font-size: 22px; font-stretch: normal; font-weight: normal; margin: 0px; position: relative;">
<span style="color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;">Bio Boom is here!</span></h3>
<div class="post-body entry-content" id="post-body-1255310595386271693" itemprop="description articleBody" style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px; position: relative; width: 646px;">
<br />
This is a great challenge for countries like Finland (a lot of forests)<br />
and Central Europe (a lot of cattle farms).<br />
<br />
What is common to both of them?<br />
<br />
After the production of ethanol (and some other beneficial compounds<span style="line-height: 18.2000007629395px;"> </span><br />
<span style="line-height: 18.2000007629395px;">(like lignosulfonate) from sulphite pulp process, very few biotechnical </span><br />
<span style="line-height: 18.2000007629395px;">processes were applied to sulphate pulp processes.</span><br />
<br />
Now it seems that ethanol can be an important product also in<br />
forest industry.<br />
<br />
And the cattle...?<br />
<br />
Methane and hydrogen are important end-products of certain anaerobic<br />
microbial processes. They were burned in previous times (I recall the<br />
waste water treatment plant of Viikki, Helsinki, where no method to<br />
<span style="line-height: 18.2000007629395px;">collect these gases were available on 70's).</span><br />
<br />
If we think the "end product of cows" we easily understand its value<br />
in anaerobic gas production. Large farms in Central Europe are ready<br />
to apply these techniques for the production of burnable gases.<br />
<br />
Third, a most important aspect too, may be easily forgotten: aerobic<br />
waste water treatment (activated sludge process) in Finnish pulp &<br />
paper mills. It has improved significantly the quality of such big rivers<span style="line-height: 18.2000007629395px;"> </span><br />
<span style="line-height: 18.2000007629395px;">like Vuoksi and Kymijoki where big integrates of P&P industry</span><br />
are situated.<br />
<br />
- To be remembered: Bio Boom consists of many chemical and<br />
technical innovations. These three issues, discussed above, are real<br />
biotechnology. Biotechnology is a term for all processes which are<br />
based on microbes (or their metabolic products like enzymes),<br />
not only chemical reactions of non-living world. This means that<br />
bioleaching of sulfide minerals is a real biotechnical process -<br />
and makes it easier to understand the difficulties to carry it on.</div>
Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-6927837924977062562014-12-11T23:22:00.000-08:002014-12-11T23:22:14.174-08:00The Role of Microbes in Biotech Boom, part 1.<span style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;">The role of microbes in the energy production has been relatively small in older times. Burning of microbial biomass has not been a clever alternative because the tiny size of microbial cells (even billions of cells, </span><span class="skype_c2c_container notranslate" data-isfreecall="false" data-ismobile="false" data-isrtl="false" data-numbertocall="+3581000000000" dir="ltr" id="skype_c2c_container" style="background-attachment: scroll !important; background-color: #fefdfa; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; color: rgb(0, 175, 253) !important; cursor: pointer !important; display: inline !important; float: none !important; font-family: Helvetica, Arial, sans-serif !important; font-size: 13px; left: auto !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; z-index: 0 !important;" tabindex="-1"><span class="skype_c2c_highlighting_inactive_common" dir="ltr" skypeaction="skype_dropdown" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; cursor: pointer !important; display: inline !important; float: none !important; font-size: 0.99em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;"><span class="skype_c2c_textarea_span" id="non_free_num_ui" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; cursor: pointer !important; display: inline !important; float: none !important; font-size: 0.99em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;"><span class="skype_c2c_text_span" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; cursor: pointer !important; display: inline !important; float: none !important; font-size: 0.99em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;">1 000 000 000</span><span class="skype_c2c_free_text_span" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; color: rgb(236, 0, 140) !important; cursor: pointer !important; display: inline !important; float: none !important; font-size: 0.99em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;"></span></span></span></span><span style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;">, can be easily be suspended in one milliliter of water - all too slow to cultivate big lots of biomass) and their water content (drying would be too much energy-consuming procedure). Wood, in opposite, has been an excellent alternative, especially when the material has been dried enough to give positive net balance of energy.</span><br style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;" /><br style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;" /><span style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;">The energy-containing metabolites of microbes, not the microbial cells themselves, have been the subject of research and development of energy production. Because the full-oxidized end-products of aerobic, oxygen-respiring micro-organisms, the fermentative microbes (like ethanol-producing yeasts) and anaerobic bacteria (like methane producers) have got a certain role in energy production. One big benefit of these applications are the non-expensive raw materials of metabolic routes like carbohydrates, manures and other stuff which has either been left from other processes or even regarded as a waste.</span><br style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;" /><br style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;" /><span style="background-color: #fefdfa; color: #333333; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13px; line-height: 18.2000007629395px;">(- to be continued soon...)</span>Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-43284630561678152242013-11-02T12:12:00.000-07:002013-11-02T12:12:38.507-07:00Challenging R&D in forest industry: not only paper and timber products<div class="separator" style="clear: both; text-align: center;">
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<span style="background-color: white; color: #37404e; font-family: 'lucida grande', tahoma, verdana, arial, sans-serif; font-size: 13px; line-height: 18px;">"The largest forest industry centre in Europe is located in South-Eastern Finland", says the back cover text of this abstract booklet of Summer School 9.-10. September 2008 by Forest Industry Institute. Future forecasts, scenarios, innovations, specified methods - in an optimistic mood on those days. - But how today? Interesting to check the outcome of these ideas. - Looking forward...</span>Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-29709760360509117732013-11-01T09:33:00.001-07:002013-11-01T09:33:40.383-07:00Integrated Prevention of Microbial Growth in ecological niches of a paper mill<div class="separator" style="clear: both; text-align: center;">
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An average paper mill consists of several sites where waterborne and biofilm microorganisms can survive and grow. Different kind of populations can be found in different environments, e.g. wet mineral and starch slurries, coating pasts, white waters, pulps and brokes as well as all wet surfaces inside the paper production systems. The effective prevention of these sub-populations is depending of the biocide alternatives (storing, fast-acting or even sporicidic compounds) available. Their use should be combined with other measures, however: the prevention of their growth by process technology, production strategies, cleaning of the processes etc. - This combined activity, if clever planned, can the be called "Integrated Prevention of Microbial Growth".<br />
<br />
The most beneficial tool for the planning of IPMG is the HACCP procedure which evaluates the potential microbiological hazards in every site and gives hints to choose the Critical Control Points in the total process.<br />
<br />
But - what does the stimulation of microbial growth in a paper mill mean?<br />
<br />
It shall be kept in mind when biological waste water treatment plant is the last step of the process water route from water source to recipient lake, river or sea. The growth conditions, in oppotie to those of manufacturing processes, should be as beneficial as possible to keep the growth rates of activated sludge or anaerobic treatment just on optimal level.<br />
<br />
We have to understand the microbes and their needs when preventing or stimulating their growth activities. The count of microbes is only one variable - their responses to temperature, pH, redox potential and other growth factors, their metabolic features (e.g. sporulation-germination cycles), their tendencies to grow in water or surfaces) and other important factors should be taken into account when planning the programs for microbe prevention (inside the mill) or stimulation (biological waste water treatment).<br />
<br />
- More about these issues in next posts...stay on the line.<br />
<br />
(Schematic picture: MENTU, J.V. 2001)<br />
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<br />Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com2tag:blogger.com,1999:blog-3964675902115159738.post-85173327845887076882013-06-21T04:54:00.000-07:002013-06-21T04:54:21.450-07:00Pioneer of environmental microbiology!<span style="background-color: white; color: #37404e; font-family: 'lucida grande', tahoma, verdana, arial, sans-serif; font-size: 13px; line-height: 18px;">I recall Dr. Howard E. Worne who was a pioneer in environmental microbiology, incl. bioleaching already on 70's. I met him in Finland when he was already over 70 years - very nice person, indeed.</span><br />
<span style="color: #37404e; font-family: lucida grande, tahoma, verdana, arial, sans-serif; font-size: x-small;"><span style="line-height: 18px;"><br /></span></span><span style="background-color: white; color: #37404e; font-family: 'lucida grande', tahoma, verdana, arial, sans-serif; font-size: 13px; line-height: 18px;"></span>
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Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com1tag:blogger.com,1999:blog-3964675902115159738.post-91919724180240007532013-06-16T05:32:00.003-07:002013-06-16T05:43:36.785-07:00The most frequent questions of industrial microbiology today?Since the beginning of my blog, several years ago, I have collected some statistics about the questions which have been redirected from Internet search activities into my blog. The following "top three" is not actually statistically analyzed but still reviews my own opinion of the most important topics . The main issues, therefore, seem to be<br />
<br />
* activated sludge<br />
* hazardous bacteria (both pathogenic strains, like coliforms, in paper products and other specified pricrobiologyocess contaminants, like sulfate reducing bacteria, SRB's)<br />
* prevention of biofilm and slime microorganisms<br />
<br />
I have mainly focused on the effects of contaminating microbes in industrial processes. Biotechnological processes like production of beverages, antibiotics etc. have therefore excluded from my blog - the only exception is biological waste water treatment, however. I have also made a comparison between commercial bioreactors (fermentors) and paper machines because many similarities can be found when observing biotechnical productions and process water systems of paper and board machines!<br />
<br />
Despite my current focus on the environmental and mining microbiology, I still follow news concerning paper industry microbiology. I am also planning a mobile mibi service for small waste water purification units, agricultural facilities as well as for pulp & paper industry.<br />
<br />
You are very welcome to follow my blog if these issues interest You!Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com2tag:blogger.com,1999:blog-3964675902115159738.post-89748842603075904702013-05-26T08:29:00.003-07:002013-05-26T08:29:34.474-07:00How to construct a rapid microbiological control for industrial processes and effluents?How to construct an ON LINE analytical procedure to control the microbial growth in non-biotechnical processes like those in mining and paper manufacturing?<br />
<br />
First of all, it would be a good idea to<b> map the microbiological problems of the process</b>. They can be slime production by biofilm bacteria, biodeterioration of valuable raw materials or products, biocorrosion by sulfate reducing bacteria - these are the main subjects but, depending on the process in question, there are others, too. As an example, bacterial spores cause hazard for the hygiene of food packaging boards and papers, fermentative/anaerobic bacteria cause bad odours etc. HACCP (Hazard Analysis & Critical Control Points) examination, applied first in food industry over decades ago, helps a lot (more about HACCP in other post).<br />
<br />
Next step (and very important one) is the <b>chose of the analytical method</b>. There are several of them and many alternatives have been reviewed already in 1990 when "RAMI-90", <i>Sixth International Congress on Rapid Methods and Automation in Microbiology and Immunology</i> was held in Helsinki-Espoo, Finland, 7-10. June 1990. The German institute "<i>Papiertechnische Stiftung</i>" has also performed evaluations of rapid mibi methods on 80's. A summarizing article called "Microbiological Control of Pigments and Fillers" was presented by me in <i>PIRA Symposium, Cambridge, England in 1997</i> and published in the series of "The Fundamentals of Papermaking Materials". It describes the evaluations performed in Research Centre of ENSO Ltd. (currently STORA ENSO Ltd) and Helsinki University / Dept. Appl.Chem. and Microbiology). Some novel methods have appeared after this publication but, as we found in this research, ATP (Adenosine Triphosphate) analysis seems to be a valuable tool even today.<br />
<br />
The<b> microbiological variables to be controlled</b> must also be taken into account. If total growth is the main subject of the control, rapid biochemical reactions like ATP Assay or staining of the cells with fluorochromes like Acridine Orange are recommended. These two measurements are relatively simple and their results - values of light emission or fluorescence - can easily be handled as raw data, derived by optical measurements. RR (Respiratory Rate) Test is slightly more complicated because a certain incubation period of the sample is needed but it can also be automatized. Two drawbacks of this method are its low sensitivity and selectivity (only microbes with aerobic respiration can be detected). Whenever some special species (like coliforms) or groups (like SRO's = Sulfate Reducing Bacteria) are to be controlled, more time and money consuming methods like selective cultivations (in PMEU) or PCR are needed - and they are also very difficult to apply into an ON LINE control system.<br />
<br />
<b>Collection and use of the data</b> derived from the processes shall also be planned. Time series with certain transformations are usually most beneficial meters to show any kind of trend in the densities of free-floating (= non-biofilm) microbes. Growth rates of single-cell microbes in water environment will usually be presented after log transformation of microbial densities which gives a straight line in xy plots when the time scale is presented with equal intervals (semi-logarithmic plot). This means that the alarm threshold should be set wisely because the amount of microbial cells increases with a factor of ten in every time unit and the period of time which are needed for growth from 10 to 100 cfu/ml or 1 000 to 10 000 cfu/ml are equal (if anything like lack of nutrients or any kind of inhibition doesn't prevent the growth). Statistical conclusions of biofilm and filamentous microbes will follow other guidelines and semi-logarithmic plot may not be the best framework to collect data. Solutions for the questions of statistical significance of rising or dropping microbial densities can be found in special textbooks like "<i>Statistical Methods in Biology</i>" by Norman T J Bailey (Edward Arnold, London). A Finnish lesson about this subject, written by me for professional training centers, is also available by request.<br />
<br />
<b>Economical considerations</b> will not be discussed deeper here because they are very much depending on the equipment and reagents. A very rough estimate for the price of one analysis is 10 - 30 € (which is, by the way, a relevant estimate for colony count analyses, too). When planning an automatized system, commercial instruments like luminometers may be applied to the system but they have to be modified to work ON LINE (sampling, dosing of reagents, cleaning of the detectors etc.). The costs of control are very much depending on the time schedules and too frequent sampling shall be avoided.<br />
<br />
<b>Conclusion: an ON LINE microbiological control system can be constructed to collect time series of microbe density data and give early warnings of hazards whenever the target organisms and their critical growth sites are mapped (HACCP) and the control method, depending of the specificity of organism(s), is chosen. Time series help to evaluate biocidic treatments, effects of the process conditions (temperature, pH, redox potential and so on), overall contamination of the process etc. and, finally, threshold levels for the alarms, based on the control experiences, can be set.</b>Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-31267635471478242292013-04-22T14:41:00.001-07:002013-04-22T14:41:21.268-07:00Novel method to produce biofuel - by E.coli!As an (originally) environmental microbiologist, I was very pleased when reading the news, delivered by BBC web site, tonight:<br />
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A novel biotech method, based on the growth of coliform bacteria, has recently been tested in laboratory conditions by British scientists. This sounds very promising because the simple nutritive requirements and rapid growth of coliforms. <i>E.coli </i>has the world record of growth rates: it can duplicate in 20 minutes when growth environment is optimal. In addition, coliforms can use sugars, derived from mechanical pulp manufacture - suits also to Finland?<a href="http://www.bbc.co.uk/news/science-environment-22253746"></a><br />
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<a href="http://www.bbc.co.uk/news/science-environment-22253746">http://www.bbc.co.uk/news/science-environment-22253746</a>Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com1tag:blogger.com,1999:blog-3964675902115159738.post-60194638609145680012013-02-20T23:50:00.004-08:002013-02-20T23:50:26.475-08:00From paper industry to mining environmentAfter my career as paper industry microbiologist (1983 - 2009) I have totally reoriented towards environmental problems of mining industry today.<br />
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Reasons for the closure of the paper microbiology development is the depression of this industrial area. No interest in rapid control methods can be found anymore. Positive attitudes still exist (esp. in Finnish innovation organisations) but "money rules" today. No economical support can be found for e.g. luminometric ON LINE methods from paper companies - and it is really a pity.<br />
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Short summary of my career in paper microbiology:<br />
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I actually started as environmental microbiologist in HU / Dep.of Microbiology, Helsinki, Viikki. I recall shortly the most interesting projects in the beginning of 80's: cyanobacteria, nitrogen fixation, Bacillus-based insecticides, soil microbiology, coliform research..and then I found myself in the projects of prof. Seppo Niemelä. We were able to perform species analyses of different waste water types and found the best indicators of paper industry effluents which were led to Lake Lohjanjärvi. Growth temperature ranges of most important indicator coliforms were also determined by Tmax method. Several scientific analyses were written and I started my doctoral thesis about environmental and clinical species of a certain coliform. - Thank you, Leena, for your help to detect plasmid-bound antibiotic resistances!<br />
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A big chance of my career happened in Autumn 1986 when I was accepted to work as the research microbiologist for Enso-Gutzeit Ltd. I had to leave my doctoral work (all documents still in my book shelf!) but I got a job where I learned everything about paper industry microbiology - from raw materials up to waste waters! There were countless persons who helped me to understand the world of paper making - I will thank them all because the name list would be too long to be published.<br />
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After some reorientation in my private life I headed towards Jyväskylä in 2006 and had the great chance to work with late prof. Christian Oker-Blom (R.I.P., Chrisse!). We constructed several project proposals for paper industry with several Finnish and foreign companies but it seemed that there were no money left for this kind of projects in paper companies anymore. Some interesting projects of air quality etc. then follows (thank you, Markus!) in the last years of 00's.<br />
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The last post of mine was the key account director of Samplion Ltd. No matter my title, I was able to perform real laboratory evaluations in JAMK laboratory and field tests in paper and paper additive companies - interesting!<br />
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In addition to the posts mentioned, I have worked as a part-time teacher for professional teaching organisations (especially TL, AEL, POHTO), companies and universities of applied sciences (especially Imatra, Jyväskylä, Kotka).<br />
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Today, as formally retired, I am more and more activated in environmental microbiology (greetings to Helge and BIOTECHTOUCH!). Coming back to those years in Viikki - the circle is now closed. I wonder if I have to reconstruct my blog but let it wait...I'll try to inform my readers in Twitter and Facebook about my reorientation. Please follow the key word "Talvivaara"...!Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com1tag:blogger.com,1999:blog-3964675902115159738.post-21077190130516622192012-12-08T05:02:00.002-08:002012-12-08T05:02:35.390-08:00A new era in microbiology: back to Pasteur's times?<br />
<h3 class="post-title entry-title" itemprop="name" style="background-color: white; color: #cc6600; font-family: Georgia, serif; font-weight: normal; line-height: 1.4em; margin: 0.25em 0px 0px; padding: 0px 0px 4px;">
<span style="color: #333333; line-height: 1.6em;"><span style="font-size: xx-small;">(first published April 25th 2010 by Juha V. Mentu)</span></span></h3>
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<span style="color: #333333; font-size: 13px; line-height: 1.6em;">The history of microbiology contains several eras with different targets. I will refer them in this way (based on my over 30 years experience as microbiologist and teacher of microbiology and biochemistry):</span></h3>
<div class="post-body entry-content" id="post-body-2968634108495208931" itemprop="description articleBody" style="background-color: white; color: #333333; font-family: Georgia, serif; font-size: 13px; line-height: 1.6em; margin: 0px 0px 0.75em;">
<br />In the beginning, <span style="font-weight: bold;">cultivation and observation of microorganisms</span> was the main target. Doctors like Pasteur and Koch were very innovative and developed intelligent culture medias and vessels to perform very delicate experiments. The everlasting fight against pathogenic microbes was the primary target but Louis Pasteur started to help eg. wine producers to solve their quality problems, caused by microbes.<br /><br /><span style="font-weight: bold;">The combination of microbiology and biochemistry</span> on the second era was very satisfying by solving questions concerning the huge amount of anabolic and catabolic processes included in microbial growth. More and more were also learned in the area of microbial ecology. Questions like "who? what? when? where? how? why?" were partially solved (ref. MADSEN,E.L. 2008. Environmental Microbiology. From Genomes to biochemistry. Blackwell Publishing).<br /><br />"Third era" can be described by the <span style="font-weight: bold;">novel methods to identify bacteria</span>. Biochemical test kits (API etc.) were replaced by Fatty Acide Methylated Ester method (FAME) by Hewlett-Packard on 80's. After it, molecular biology methods, based on ribosomal RNA and DNA, helped to construct the development lines of microorganisms.<br /><br /><span style="font-weight: bold;">Today is the time of new era</span>. We know the "family trees" of bacteria but we should now continue with environmental microbiology and microbial ecology to solve questions like "How, why, by whom and in which conditions will the raw materials of paper industry be biodeteriorated?", "How can we prevent these processes by setting the process conditions unsuitable for those biochemical processes?", "Can we prevent the growth of biofilms and slimes in an ecological way?", "How to prevent selectively the growth of toxin producers like <span style="font-style: italic;">Bacillus cereu</span>s in paper and board processes?", how to fight against <span style="font-style: italic;">Legionella </span>in paper industry?".<br /><br />Names are not the most important thing. Most important is, how the bacteria act in different ecological niches of a paper machine. This work has to be done by using simulations of paper processes which is possible by wet end simulators of research units (as an example: VTT in Jyväskylä, Finland) and laboratory/field instruments.<br /><br /><span style="line-height: 1.6em;">We are - and we shall - turn back to the era of Pasteur & Koch:</span><span style="line-height: 1.6em;"> </span><span style="font-weight: bold; line-height: 1.6em;">the names are already known, and we shall now investigate, what the contaminating microbes are doing in the industrial processes and how to prevent losses of raw material, machine stops and poor quality of the products by simulating growth processes in small-scale tests, performed in the laboratory or in the field, by the machines themselves.</span></div>
Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-86514530152144903152012-12-03T15:43:00.000-08:002012-12-03T15:43:01.079-08:00Monitoring of microbial growth and sporulation<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN5TlIXo0w1wPsCUe0Kp7WFR-0Iugssxtt_Fk1KRrYIYwqe5b7Y1eC2wFle7l-cXbb9fP8v893d8rxg5ltOSKqjYy2zk8-WctiTEsmze5L3vS3mowwkHCHdfbAPce85jJARotFO2l6BFQ/s1600/esitys3.tif" imageanchor="1" style="margin-left:1em; margin-right:1em"><img border="0" height="260" width="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN5TlIXo0w1wPsCUe0Kp7WFR-0Iugssxtt_Fk1KRrYIYwqe5b7Y1eC2wFle7l-cXbb9fP8v893d8rxg5ltOSKqjYy2zk8-WctiTEsmze5L3vS3mowwkHCHdfbAPce85jJARotFO2l6BFQ/s400/esitys3.tif" /></a></div>
<b>pH, temperature, nutrients and biocides</b> are usually observed when the risks of microbial growth and sporulation inside paper machines should be estimated. Fourth important factor, <b>time</b>, will be often ignored, no matter it plays a most significant role in paper process microbiology.
The simple figure above shows two important parameters which reveal the microbiological status of the white water in an anonymous paper machine (my personal data ca. 2006): <b>Colony Count</b> (CC, indicating the count of vegetative bacterial cells per ml) and <b>Spore Count</b> (SC, indicating the count of bacterial spores per ml). It is obvious that this very sample contains relatively high amounts of nutrients to secure the rapid growth of bacteria (the growth rates of bacteria, carried by white water, are usually much lower but bacterial densities, in opposite, on a very high, stabile levels). What is especially important in this case is the <b>rapid increase of bacterial spores</b> - producers of process biofilms after their outgrowth and risks for product hygiene in their original form - which seems to take place after ca. 0,5 days storage time. This event takes place practically always when the flow of white water, pulp and broke have been stopped during the delays of constant machine operation. The hygiene status of the total process would then be very important to know - how much spoiled water and broke can be supplied from towers to the process, are there risks to have biodeteriorated raw materials from the storage tanks, is there any need to use shock dosing of biocides in some sites etc. - but it cannot be done by using CC, SC or any other cultivation technique which give analytical results only after several days' incubation periods. <b>Long analytical delays in colony count analyses also totally prevent the efficient application of HACCP hygiene control procedures into paper machine environment</b>. - These are the facts which motivate me personally to continue planning rapid, ON LINE process hygiene methods.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-91031193026657299502012-10-31T05:42:00.001-07:002012-10-31T05:42:53.028-07:00Microbiology Services for Paper Industry by BIOTECHTOUCH<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1tAeSKtc0bE54sr8YSiPOVQQeFif2hTF8xnqSzUXPrk9M8boRzdaQUdPeJUyiIT-HpPQXWCUiq05BIIVYYZXEvJDL6GR3d-qinoWRfEC9vcjj4xnOEcr7qKb2kDhgj26lIVDx5CHMAV0/s1600/BIOTECHTOUCH.jpg" imageanchor="1" style="margin-left:1em; margin-right:1em"><img border="0" height="400" width="399" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1tAeSKtc0bE54sr8YSiPOVQQeFif2hTF8xnqSzUXPrk9M8boRzdaQUdPeJUyiIT-HpPQXWCUiq05BIIVYYZXEvJDL6GR3d-qinoWRfEC9vcjj4xnOEcr7qKb2kDhgj26lIVDx5CHMAV0/s400/BIOTECHTOUCH.jpg" /></a></div>
BIOTECHTOUCH is a group of consulting specialists for process industry and environmental research. Our main competence areas are biocides, microbiology and toxicology. We have focused especially on the problems of paper industry (raw material, process and product hygiene as well as effects of waste waters on recipients). This is also my own area of activity today, after my departure from my previous post in SAMPLION Ltd.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com1tag:blogger.com,1999:blog-3964675902115159738.post-18495931167283561392010-06-28T12:05:00.000-07:002010-06-28T12:26:43.035-07:00Future methods for P&P microbiology.It seems that new methods for P&P microbiology are needed.<br /><br />After discussions in PulPaper Congress in Helsinki, June 2010, it is obvious that traditional colony count methods cannot tell the truth about process problems.<br /><br />These methods, originally developed for clinical microbiology, seem to have too high nutrient content. They cannot, therefore, select the "troublemakers" from the process samples. Bacteria like Gram-negative rods and Bacillus sp. are overestimated in these analyses but eg. filamentous bacteria cannot grow on common, commercial agar media.<br /><br />Identification of bacteria can be important in some cases. Food poisoning species from the genuses <span style="font-style:italic;">Bacillus, Staphylococcus</span> and <span style="font-style:italic;">Clostridia</span> and hygiene indicators like coliforms, <span style="font-style:italic;">E.coli</span> and <span style="font-style:italic;">Enterococci</span> should be found in raw material control in the production of high hygiene products (LPB, other food-grade cartonboards and papers as well as tissue-type products). If not covered by other bacteria, they can be found with CC analyses. PCR also gives a good way to distinct them among other bacteria.<br /><br />These methods cannot reveal some severe problems, however. Biofilm formation and comparative biocide testing are two types of investigations which cannot be performed with agar cultivations or molecular biology methods. They should be done either in machine trials or simulations. PMEU methods seem to be the best alternatives for rapid evaluation of biofilm formation and biocide testing today because they exclude all artefacts, caused by artificial growth medium (in colony counts) or too high selection of microorganisms (in PCR). CC's and PCR can be adopted to certain tests but when the subject of the study is to see, what happens in the real paper processes, simulation methods like PMEU shall be chosen.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com6tag:blogger.com,1999:blog-3964675902115159738.post-13235315569792488832010-04-25T03:02:00.000-07:002010-04-25T03:44:41.593-07:00Trends in environmental microbiology with references from paper industry microbiologyThe history of microbiology contains several eras with different targets. I will refer them in this way (based on my over 30 years experience as microbiologist and teacher of microbiology and biochemistry):<br /><br />In the beginning, <span style="font-weight:bold;">cultivation and observation of microorganisms</span> was the main target. Doctors like Pasteur and Koch were very innovative and developed intelligent culture medias and vessels to perform very delicate experiments. The everlasting fight against pathogenic microbes was the primary target but Louis Pasteur started to help eg. wine producers to solve their quality problems, caused by microbes.<br /><br /><span style="font-weight:bold;">The combination of microbiology and biochemistry</span> on the second era was very satisfying by solving questions concerning the huge amount of anabolic and catabolic processes included in microbial growth. More and more were also learned in the area of microbial ecology. Questions like "who? what? when? where? how? why?" were partially solved (ref. MADSEN,E.L. 2008. Environmental Microbiology. From Genomes to biochemistry. Blackwell Publishing).<br /><br />"Third era" can be described by the <span style="font-weight:bold;">novel methods to identify bacteria</span>. Biochemical test kits (API etc.) were replaced by Fatty Acide Methylated Ester method (FAME) by Hewlett-Packard on 80's. After it, molecular biology methods, based on ribosomal RNA and DNA, helped to construct the development lines of microorganisms.<br /><br /><span style="font-weight:bold;">Today is the time of new era</span>. We know the "family trees" of bacteria but we should now continue with environmental microbiology and microbial ecology to solve questions like "How, why, by whom and in which conditions will the raw materials of paper industry be biodeteriorated?", "How can we prevent these processes by setting the process conditions unsuitable for those biochemical processes?", "Can we prevent the growth of biofilms and slimes in an ecological way?", "How to prevent selectively the growth of toxin producers like <span style="font-style:italic;">Bacillus cereu</span>s in paper and board processes?", how to fight against <span style="font-style:italic;">Legionella </span>in paper industry?".<br /><br />Names are not the most important thing. Most important is, how the bacteria act in different ecological niches of a paper machine. This work has to be done by using simulations of paper processes which is possible by wet end simulators of research units (as an example: VTT in Jyväskylä, Finland) and laboratory/field instruments (like biofilm detectors in the processes or PMEU incubators by Samplion Ltd.). <br /><br />The role of PMEU is getting more and more important because this method helps to detect microbial growth of different types (biofilms included) in a very short period of time as well as to test simultaneously the effects of alternative biocides in small-scale tests whose growth parameters match with the growth conditions in the real processes.<br /><br />We are - and we shall - turn back to the era of Pasteur & Koch: <span style="font-weight:bold;">the names are already known, and we shall now investigate, what the contaminating microbes are doing in the industrial processes and how to prevent losses of raw material, machine stops and poor quality of the products by simulating growth processes in small-scale tests, performed in the laboratory or in the field, by the machies themselves. </span>Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-46790946339343809972009-11-14T10:40:00.000-08:002009-11-14T10:56:30.904-08:00PMEU as a tool for biofilm testing<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgah5zhJ9qEC7VncBmXrrjw9QD55iBDAHIMHnLQzYfYRy3wARLw7i-LRpS01HNqJjcO-vxZbj9A-83Z5RVA2rwQL89kwE6hrLLf1ntk7CwwppIHL1jGA3ImyCXtzTkIrL-YeBliTyQLPY/s1600-h/BIOFILM_SYRINGESjpg.jpg"><img style="TEXT-ALIGN: center; MARGIN: 0px auto 10px; WIDTH: 400px; DISPLAY: block; HEIGHT: 300px; CURSOR: hand" id="BLOGGER_PHOTO_ID_5404031174541656754" border="0" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgah5zhJ9qEC7VncBmXrrjw9QD55iBDAHIMHnLQzYfYRy3wARLw7i-LRpS01HNqJjcO-vxZbj9A-83Z5RVA2rwQL89kwE6hrLLf1ntk7CwwppIHL1jGA3ImyCXtzTkIrL-YeBliTyQLPY/s400/BIOFILM_SYRINGESjpg.jpg" /></a><br /><div></div><br /><br /><br />PMEU Method was presented in PIRA Paper Industry Symposium, Barcelona, in October 2009. The basic PMEU model can be applied to diverse test types which help to construct biocide programs for the prevention of sessile and biofilm growth of bacteria in paper machines.<br /><br />The picture above shows a typical test situation where process water sample, biocide and test coupon (made of steel) are installed in a PMEU syringe. Prevention of sessile growth can be monitored with ATP Assay, biofilm growth with UV Epifluorescence Microscopy.<br /><br />In addition to the basic PMEU model, the novel PMEU Spectrion which measures the turbidity of all ten samples automatically, can be applied to any microbiological growth / growth prevention test of liquid or slurried samples from paper manufacturing processes. This device can handle also relatively turbid samples because it stops the mixing of the samples before turbidity measurement, allowing heavy particles (like mineral pigments) to sediment and enables therefore the measurement of bacterial cloudiness of the sample.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com6tag:blogger.com,1999:blog-3964675902115159738.post-55658317410426222132009-09-18T09:11:00.000-07:002009-09-18T10:16:30.600-07:00Competition between tube and colony count methodsAll began with beef broth.<br /><br />Dr. Louis Pasteur invented this method for the cultivation of diverse microbes. The famous "Swan Neck" trial was also performed with beef broth.<br /><br />One of the first solid media for microbiological cultivations was the surface of a potato, presented by Dr. Robert Koch.<br /><br />Colony counts began to be more and more favored by microbiologist because the colonies gave a chance to the immediate isolations of strains. The visual appearance of colonies on solid agars also help to identify the actors of the play, the species of a sample. Membrane filtration method also rise the popularity of colony count method, as well as the relatively good accuracy of colony count analyses, compared to the broth methods.<br /><br />The role of the tube methods, however, has turned to be more important today. The limitations of the colony count method, correlated with the features of the samples (turbidity, toxic compounds etc.) and the slow growth (compared to the broth cultivation), are obvious. Testing of growth-affecting compounds like biocides are also easier and more reliable to perform in a solid media. When testing of those agents shall be done in the real environment (like the process water of a paper machine), the only alternative is the tube test. Detection of the response of stimulating and inhibiting agents can be done with various methods (photometry, colorimetry, turbidity, ATP Assay etc.) easily. Quantitative analyses of microbial counts can also be performed much faster with a (MPN) tube method than with the colony count method.<br /><br />As a conclusion: colony count methods suit very well for purposes like the counting of CFU values as well as the selective cultivations of the total population to detect certain microbial groups. Testing of the effects of diverse growth factors (temperature, pH, biocidic and biostatic compounds etc.) should be performed with the tube methods, however. Growth on/in a solid medium does not correlate with the growth of the population in its original environment. Biofilm trials shall always be performed in liquids, never on solid media.<br /><br />Various analytical tools have been developed for the measurement of the growth responses (pH, turbidity, impedance) automatically from the tubes and the most novel method, PMEU "mini-fermentor", gives the chance to perform all tests with the highest speed and - if needed - in the original samples to simulate the real growth environment of the microbial population. This method will be presented in PIRA Paper Conference, Barcelona, in next October.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-66226606493266656872009-08-28T10:03:00.000-07:002009-08-28T10:11:30.653-07:00A new PMEU application: quantitative MPN analyses of microbial countsPMEU method is based on the rapid cultivations of several samples. The old idea to apply it in MPN (Most Probable Number) analyses has now proven to be correct: referring the Finnish Standard Book "SFS-KÄSIKIRJA 94: Mikrobiologiset vesitutkimusmenetelmät" (Methods for Microbiological Water Analysis) and discussions with specialists, PMEU can be used as an alternative, rapid method instead of the traditional technique, tube series in water bath or in an incubator. PMEU itself works as an incubator with a temperature deviation of < 0.1 oC. <br /><br />A combination of 4 (levels of dilutions) * 5 (repeats) allows to follow the Finnish standard SFS 4447 (The Tube Method in Microbiological Water Analysis) as well as standards derived of it like SFS-EN ISO 9308-3 (for and coliforms) and SFS-EN ISO 7899-1 (for enterococci). Standards usually give MPN tables in the framework of 3*5 tubes (eg. for dilutions from 0 to 0.01) but PMEU gives an extra level (eg. 0 to 0.001) which covers a wider range of microbial counts. Samples with unknown levels of microbial densities are therefore easier to analyse correctly. <br /><br />It seems that the leading status of membrane filtration has revised today. There are types of samples which are difficult or impossible to analyse with them (too much suspended solids etc.) and tube tests like MPN should be chosen. PMEU Tube Tests should be preferred also in situations where fast results (in hours, compared with days with colony count analyses) are needed.<br /><br />The microbiological control of certain paper industry samples (pulp slurries,starches, minerals) are better to perform with tube methods. An example of the priority of the tube methods can be seen when samples with polymers should be analyzed: polymers tend to stuck membranes immiadely but do not prevent any analyses performed with tube methods. Rapid detection of harmful or hazardous bacteria can also be done faster with selective broths than in/on selective agars.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-30766888750900281292009-08-16T06:40:00.000-07:002009-08-16T06:48:17.327-07:00Applications of PMEU method for biofilm research and testing of biocides against biofilm growth<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuS14sLoIsMmaCGZWXU5bjuYHU5KuHVnpBPs_RoS8ctl7c7wsfyNgBaU9Y4RXNJfUMrFmYGLscAk_Rj1eZfjWT8UjUbH_VBNsvuc7V2ZefAb4jo_FRR3hzmtEXIBaVOFTBqSx6bxaiVBo/s1600-h/test_plate_9_ref_100x_AO.jpg"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 297px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuS14sLoIsMmaCGZWXU5bjuYHU5KuHVnpBPs_RoS8ctl7c7wsfyNgBaU9Y4RXNJfUMrFmYGLscAk_Rj1eZfjWT8UjUbH_VBNsvuc7V2ZefAb4jo_FRR3hzmtEXIBaVOFTBqSx6bxaiVBo/s400/test_plate_9_ref_100x_AO.jpg" border="0" alt=""id="BLOGGER_PHOTO_ID_5370556987705284578" /></a><br />Paper machine biofilms have been studied already several years with PMEU method by IM. Test coupons, made of steel brands used in paper machines, have been installed inside PMEU syringaes and the growth has been observed with UV Epifluorescence Microscopy after a short incubation period (see picture above).<br /><br />This technique has now been modified for ordinary light microscopes, too. Steel coupons have been replaced by specified glass slides and the Gram-stained biofilms can be observed with Bright Field Microscopy - no expensive epifluorescence microscopes are needed in this application.<br /><br />This method will detect all biofilm-producing microbes and testing of biofilm-preventing biocides is also possible simultaneously. Primary attachers typically appear on the slides in just hours and mature biofilms are available in 12...24 hours. This application is very suitable for all areas of industry where the hygiene of surfaces is important. It can also be applied in every environmental research projects where the formation of biofilms in natural water environments is the subject of the study. Hygiene control of public swimming pools etc. also benefit of this method.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-90911251339517777652009-08-08T10:40:00.000-07:002009-08-08T11:06:54.491-07:00Sulphate Reducing Bacteria in paper industry.SRB is an interesting group of bacteria which can use sulphate as an electron acceptor for the respiration. Despite the chances of certain other bacteria to use sulphate as the sulphur source for their S-containing cell components, the "real" sulphate reducers transform SO4(2-) to S(-2) in their energy metabolism and oxygen actually inhibits their growth - they are therefore obligate anaerobes. Certain yield of energy may be achieved through fermentation by SRB's but this type of metabolism is regarded as relatively insignificant one for them.<br /><br />These bacteria have first detected in waste waters of sulphite pulp mills but modern paper machine processes can also induce their growth if certain sulphur-containing compounds are available.<br /><br />In addition to H2S production (which is a hazardous gas), colour problems can arise because the metal sulphides. FeS is an indicator compound in the analytical detection of SRB's but also a harmful agent of discolorization of paper and paperboard. Last but not least, SRB's have been shown to be conneceted to a certain type of iron corrosion and it is all possible to find those problems still today whenever technical structures with poor steel quality and certain types of organic deposits on their surfaces are combined.<br /><br />SRB's have also other, peculiar features like the tendency to follow non-exponential growth curve. They have been the subject of firm microbiological research only since the middle of 20th century because their need of anaerobiosis was not understood earlier.<br /><br />FINNOFLAG Ltd. is currently developing a novel method for the sensitive detection of SRB's with PMEU method - more about this topic in next posts.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com2tag:blogger.com,1999:blog-3964675902115159738.post-53806249748588109432009-07-24T07:01:00.000-07:002009-07-24T07:39:50.100-07:00The need of bacterial identification?IM has discussed about alternative methods for the detection of hazardous or harmful bacteria with Dr. Elias Hakalehto. <br /><br />It is most important to know the pathogens which will appear in patient samples. Clinical microbiologists shall know who are the enemies of the ill people: their metabolic capabilities, antibiotic resistence patterns etc. Their overall features are easy to find from literature or internet whenever the name of the species is known. This identification can be performed by selective cultivations on agar plates or in PMEU incubator, and further tests like microscopic examinations, API ID systems, immunological tests and/or PCR can be done to confirm the basic identification.<br /><br />Paper mill is definitely another challenge for microbiologist. In some (relatively rare cases) the names of microorganisms are important to know: if the product shall have high hygiene quality (like LPB and other food-grade cartonboards) or questions about bioterrorism have been arisen (spore-forming <span style="font-style:italic;">Bacillus anthracis</span> as an example). The occurrence of <span style="font-style:italic;">Legionella pneumophila</span> is also a risk in the waste water treatment of paper industry today. Selective cultivations, either on plates or in PMEU, are the solid solutions for continuous microbiological control in those cases. PMEU is preferred because its speed (hours, compared to days with colony count analyses).<br /><br />Papermakers shall focus more on the metabolic activities than the names of bacteria which they are living with in paper mills, however. Continuous inoculation of the paper production processes by contaminants, delivered with incoming lots of starches, mineral fillers, raw water, dry pulp etc. shall be controlled to avoid spoilage (amylolytic activity as an example), biofilm and slime growth, tastes and odours, spots and colours in the product etc. Because the wide range of bacterial species and their origin from the nature itself, clinical methods do not suit very well for this monitoring. There is no time to start labourous cultivations, pure cultures and identifications when the bacterial input continues day and night, "7/24". PMEU seems to be an excellent tool to check the basic features of process populations, their biocide resistence patterns included.<br /><br />One important fact must also be taken into account. There are a lot of harmful microbes which actually cannot be cultivated on agar at all. One example are certain filamentous bacteria which may cause biofilm layers into the processes. They can be cultivated in some broths, however, but the usage of the original samples as the growth medium is the best way to detect them all. This can be done with ordinary mb laboratory equipment or with PMEU incubator.<br /><br />Identification of bacterial species is still needed when the mapping of contamination routes into the processes is the subject of the study. IM will discuss about the microbiological mapping in his next posts.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-41047033783339274762009-07-21T11:31:00.000-07:002009-07-21T11:57:31.892-07:00Statistical methods in microbiology.IM has discussed about the evaluation of novel microbiological methods with several professionals. His knowledge of statistical methods in microbiology bases on the lessons by Prof. Seppo Niemelä, who was (and still is) a well-known specialist in this not-so-well-known area of microbiology.<br /><br />Testing of microbiological data is more complicated than similar analyses in chemistry. The main reason is the model of repeat distribution: chemistry follows the ordinary normal distribution but the colony counts of microbiological analyses are featured by the Poisson distribution. The reason for this difference is easy to understand: the count of molecules is overwhelming when compared to the limited count of colonies in microbiological cultivations. The dependence of variance on the mean of the data is another problem of colony count analyses, preventing the usage of parametric methods.<br /><br />Luck enough, there are some non-parametric statistical analyses for Poisson-distributed data, helping the comparisons of means and trends of colony count results. <br /><br />A novel problem seems to have arisen in microbiological evaluations since 70's. Many modern, automatized instruments of microbiology are not based on the measurements of chemical concentrations or counts of colonies but on specified metabolic activities of microbes. Examples of these analytical procedures are eg. measurements of impedance, turbidity, pH or CO2 production. Because these parameters are in a close connection to the growth rates - and to a new parameter, time - , their evaluations are very challenging procedures.<br /><br />- More in next posts...Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com1tag:blogger.com,1999:blog-3964675902115159738.post-83655565837669192832009-07-08T04:13:00.000-07:002009-07-08T04:39:16.298-07:00Identification of bacterial species.Questions about the identification of certain bacterial species are rising time after time. Paper mills - and their customers - are interested to know if the product, paper or board, contains harmful bacteria like food-poisoning bacteria, or even hazardous ones. Could terrorists inoculate a paper machine with <span style="font-style:italic;">Bacillus anthracis</span>? Could <span style="font-style:italic;">Listeria</span> live in wet end processes? Bird-flu?<br /><br />Another reason for the question is the safety of working environment. Are high densities of bacteria in the wet end air dangerous? <br /><br />Fortunately all information of the environmental needs, growth factors and capability to survive dry end treatment (="pasteurization") show that there is no need to worry if those real pathogens could be encountered in paper industry products.<br /><br />There are still some areas inside paper mill where the identifications are needed, like<br /><br />* food-poisoning, sporeforming bacteria (most important: <span style="font-style:italic;">Bacillus cereus</span>)<br />* bacteria causing raw material breakdown (amylolytic ones etc.) <br />* potential primary attachers, causing biofilm formation (several genus)<br />* bacteria which can cause health symptoms and diseases(<span style="font-style:italic;">Legionella pneumophila</span>, certain coliform bacteria)<br /><br />Identification of specified bacteria from wet end population isn't easy task. Mixed population, sample matrix, low number of target organisms, their distribution inside the machine all lead to very challenging task.<br /><br />I will refer the traditional and novel methods for the detection of specified bacteria in next posts. Coming back...Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0tag:blogger.com,1999:blog-3964675902115159738.post-4485917233909004022009-07-05T21:35:00.000-07:002009-07-05T23:01:03.980-07:00Connections of paper industry microbiology to other sectors of microbiology: what is actually needed?To make any <span style="font-weight:bold;">definitions of paper industry microbiology</span>, it makes sense to compare it with elder sectors of microbiology. Despite the microbiological problems of the paper processes and the paper products have been obvious since the beginning of machine-scale production of paper and board on 19th century, their effects have get worser when the scale, speed and raw material repertoir have increased during last decades. The tradition of the microbiological control, as well as the history of biocide research, intended in the "healthcare" of paper and board machines is therefore much shorter than in related areas like in dairy or food microbiology.<br /><br /><span style="font-weight:bold;">Paper manufacturing processes could be seen as ecosystems where several, complicated microbiological processes are continuing day and night</span>. Microbial communities perform their important role as the actors of chemical transformations which shall modify most living and very many non-living substances into forms which will support the growth of other living creatures. Many species of immigrant bacteria, coming into the processes with the raw water, mechanical fibres and several additives, will feel fine: favourable temperature, pH level and nutrient concentrations, as well as good aeration and a huge supply of contact surfaces to build up biofilms, are available for them. They really do not make any difference between their lives outside and inside of the paper mill walls.<br /><br />Unfortunately (not for the microbes but for the paper production) there are some features of paper machines which are similar with <span style="font-weight:bold;">fermentor and bioreactor processes of biotechnological industry</span>. So many growth factors (some of them were mentioned above) will be kept on so controlled levels that the adaptation of certain microbiological population cannot be avoided. It shall also be kept in mind that the long running periods will increase the microbiological risks by allowing long growing periods of microbes inside the machines. <br /><br />How to control these problems?<br /><br />Measures to dose biocidic compounds into the processes cannot be avoided because the conditions of paper and board machines cannot be adjusted on biocidic levels: the rise of the overall temperature over +80 oC is impossible, like the rise of pH value over 12. Before significant technical improvements to prevent the microbial growth in the paper machine processes could be done (if ever), <span style="font-weight:bold;">the biocidic treatments and their rapid control methods like ON LINE biofilm measurements and frequent (at least once per 8 hours) AT LINE microbiological control of the main contaminating routes, wet end processes and towers containing white waters, pulps and brokes</span> are the most important tools to secure the runnability of the machines and the quality of the products. <br /><br /><span style="font-weight:bold;">With the price of only 2-3 jumbo rolls can reliable instruments for the AT LINE microbiological control of the wet end processes be bought today</span>. Alternative methods, many of them representing molecular biology methods, are available, but those which can show not only the counts of certain species but also the overall metabolic activities of the waterborne microbes and their potential to produce biofilms should be preferred. <span style="font-weight:bold;">A combination of PMEU incubations and ATP Assays, with the addition of PCR if needed</span>, is the most recommended procedure to show the effects of biocides on the microbial activity. PMEU method can be applied to biofilm testing, too.<br /><br />The most important thing is that <span style="font-weight:bold;">not only the counts of microbes</span> (how high they may ever been) <span style="font-weight:bold;">but also their overall metabolic activity and certain actions</span> like breakdown of starches by amylase enzymes or production of H2S and H2 in anaerobic conditions shall be controlled all the time when the machines are running. <span style="font-weight:bold;">All the laws of microbial ecology are present both in the nature and inside the machines</span> - and they can lead to severe problems if counteracting does not work.Juha V. Mentuhttp://www.blogger.com/profile/10956547973149093054noreply@blogger.com0