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
* activated sludge
* hazardous bacteria (both pathogenic strains, like coliforms, in paper products and other specified pricrobiologyocess contaminants, like sulfate reducing bacteria, SRB's)
* prevention of biofilm and slime microorganisms
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!
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.
You are very welcome to follow my blog if these issues interest You!
Showing posts with label biotechnology. Show all posts
Showing posts with label biotechnology. Show all posts
Sunday, June 16, 2013
Sunday, July 5, 2009
Connections of paper industry microbiology to other sectors of microbiology: what is actually needed?
To make any definitions of paper industry microbiology, 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.
Paper manufacturing processes could be seen as ecosystems where several, complicated microbiological processes are continuing day and night. 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.
Unfortunately (not for the microbes but for the paper production) there are some features of paper machines which are similar with fermentor and bioreactor processes of biotechnological industry. 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.
How to control these problems?
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), 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 are the most important tools to secure the runnability of the machines and the quality of the products.
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. 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. A combination of PMEU incubations and ATP Assays, with the addition of PCR if needed, is the most recommended procedure to show the effects of biocides on the microbial activity. PMEU method can be applied to biofilm testing, too.
The most important thing is that not only the counts of microbes (how high they may ever been) but also their overall metabolic activity and certain actions 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. All the laws of microbial ecology are present both in the nature and inside the machines - and they can lead to severe problems if counteracting does not work.
Paper manufacturing processes could be seen as ecosystems where several, complicated microbiological processes are continuing day and night. 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.
Unfortunately (not for the microbes but for the paper production) there are some features of paper machines which are similar with fermentor and bioreactor processes of biotechnological industry. 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.
How to control these problems?
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), 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 are the most important tools to secure the runnability of the machines and the quality of the products.
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. 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. A combination of PMEU incubations and ATP Assays, with the addition of PCR if needed, is the most recommended procedure to show the effects of biocides on the microbial activity. PMEU method can be applied to biofilm testing, too.
The most important thing is that not only the counts of microbes (how high they may ever been) but also their overall metabolic activity and certain actions 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. All the laws of microbial ecology are present both in the nature and inside the machines - and they can lead to severe problems if counteracting does not work.
Monday, February 9, 2009
Challenges of Biotech
IM will refer the excellent book "The Biotech Investor" by Tom Abate (Owl Books, 2003, New York) again. IM also tries to reserve his time to read it through, no matter it is a dense collection of biotech and marketing facts.
In the preface of this book Tom Abate says:
"Biotechnology is an experimental field. Only a handful of of biotech companies currently have products on the market. The vast majority of biotech firms run at a loss during long developmental cycles aimed at proving their founding thesis. Experiments take time, and they often fail. Even when experiments have been done, and their results analyzed and presented at scientific meetings, biotech medicines undergo an excruciating process of regulatory review the can lead to approval, rejection or demands for more testing...In biotech time, development horizons strech for years, even decades."
This is familiar for every modern biotech researchers. Dr. Abate refers medicine research but relatively similar problems may arise when a novel microbiological analyse method is the subject of the research. Approval is then depending not on the health of the customers but the potential markets (IM's opinion). IM still thinks that such a development task can be fulfilled in only years, but marketing may be a challenging task, indeed.
Contacts between paper industry personnel and biotech researchers shall be developed. There are other alternatives than the traditional fairs and exhibitions: discussions in Internet blogs, nings etc. would help significantly to present all modern microbiological tools and evaluate their use in paper industry microbiology. Unfortunately the main problem, time, still stays, even gets worser: people tend to be in a hurry in their working life today. To reserve a period, even short, to investigate new methods will still be worth to do!
In the preface of this book Tom Abate says:
"Biotechnology is an experimental field. Only a handful of of biotech companies currently have products on the market. The vast majority of biotech firms run at a loss during long developmental cycles aimed at proving their founding thesis. Experiments take time, and they often fail. Even when experiments have been done, and their results analyzed and presented at scientific meetings, biotech medicines undergo an excruciating process of regulatory review the can lead to approval, rejection or demands for more testing...In biotech time, development horizons strech for years, even decades."
This is familiar for every modern biotech researchers. Dr. Abate refers medicine research but relatively similar problems may arise when a novel microbiological analyse method is the subject of the research. Approval is then depending not on the health of the customers but the potential markets (IM's opinion). IM still thinks that such a development task can be fulfilled in only years, but marketing may be a challenging task, indeed.
Contacts between paper industry personnel and biotech researchers shall be developed. There are other alternatives than the traditional fairs and exhibitions: discussions in Internet blogs, nings etc. would help significantly to present all modern microbiological tools and evaluate their use in paper industry microbiology. Unfortunately the main problem, time, still stays, even gets worser: people tend to be in a hurry in their working life today. To reserve a period, even short, to investigate new methods will still be worth to do!
Saturday, February 23, 2008
A paper machine can be regarded as an ECOSYSTEM, whose conditions are very stable because the strict adjustments of the process. It also acts as a BIOREACTOR with a continuous supply of nutrients and output of aged culture with its metabolites.
An essential feature of a paper machine process is its environmental stability (temperature, pH, redox potential, nutrients, stimulative and inhibitive factors etc.) which leads to the development of a selected, accommodated microbial populations in ecological "niches" all over the machine. The risk of microbial problems cannot usually be taken into account when optimizing these controls. This can lead to an active, waterborne population of various bacteria with total counts of even 1000 000 000 cfu/ml. Many essential raw materials of the paper production like starches, mineral fillers and coating paste components have also beneficial effects on the growth and activity of microorganisms.
These microbiological problems get ever worse by the formation of biofilms and slime layers. Aged biofilms are not only restricted sites of microbial growth but they also release bacteria and bacterial spores into the water circulations of the paper machine.
Storage tanks of raw materials can be regarded as batch fermentors where the typical growth steps LAG, LOG, STAT and KILL can be detected during extended storing periods. A paper machine itself acts like a continuous culture bioreactor or a chemostat, securing stable growt environment of the process-adapted microbial population.
An essential feature of a paper machine process is its environmental stability (temperature, pH, redox potential, nutrients, stimulative and inhibitive factors etc.) which leads to the development of a selected, accommodated microbial populations in ecological "niches" all over the machine. The risk of microbial problems cannot usually be taken into account when optimizing these controls. This can lead to an active, waterborne population of various bacteria with total counts of even 1000 000 000 cfu/ml. Many essential raw materials of the paper production like starches, mineral fillers and coating paste components have also beneficial effects on the growth and activity of microorganisms.
These microbiological problems get ever worse by the formation of biofilms and slime layers. Aged biofilms are not only restricted sites of microbial growth but they also release bacteria and bacterial spores into the water circulations of the paper machine.
Storage tanks of raw materials can be regarded as batch fermentors where the typical growth steps LAG, LOG, STAT and KILL can be detected during extended storing periods. A paper machine itself acts like a continuous culture bioreactor or a chemostat, securing stable growt environment of the process-adapted microbial population.
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