Monday, February 16, 2009

Transfer of microbiological control from institutes to mill labs

Rapid development of analytical microbiology has been obvious during last 20 years.

After the beginning of IM's career in paper industry (est. 1982) a significant increase of novel methods has taken place. Slow and labourous colony count analyses have been replaced with novel, advanced methods in certain laboratories on 1990's.

Biomass, surface hygiene, condition of activated sludge, biofilm formation - among even more subjects - can be assayed by luminometric methods today.

Light and UV microscopy is another basic tool of paper industry microbiology today. Very valuable results have been achieved with TEM on 1980's and articles about sporeforming bacteria and biofilms, based on electron microscopy, have published by researcher all over the world. TEM is, however, such an advanced research instrument which is practically impossible to apply into everyday microbiological control of pulp and paper mills. Confocal microscopy has given brand new ideas about the structure of biofilms but it is also a too complicated method for mill labs. In opposite, light and epifluorescence microscopy aren't too expensive; they definitely need a lot of training for the personnel which is no big problem, however: in Finland (and IM is sure, in other countries, too) are training companies who will have annual microbiology courses for paper industry under titles like "Paper Industry Microscopy" and "Methods for Process and Product Hygiene in Paper Industry".

Tools of molecular biology have replaced the previous generation's major tool, FAME (Fatty Acid Methylated Esters - an application of gas chromatography to perform identifications of bacteria). But the limits of PCR and similar methods are obvious: they cannot show what is really happening inside the machines! They only give - valuable, of course - information about microbial species but do not explain and forecast those metabolic reactions, succession of population, risk of biofilm formation etc. which are more important for the drive of machines, good housekeeping of raw materials and product hygiene.

Basic methods of modern microbiology like DEFT, ATP Assay, PCR and other should therefore be combined with simple simulators, driven in mill labs. This is already possible: the first system for this target, PMEU (Portable Microbiological Enrichment Unit) has been tested and used by IM since the beginning of 2000's and it has been proven to be a most valuable tool for rapid raw material, process and biofilm studies today.

An ecological point of view shall be applied to everyday mb control of the pulp and paper mills. This question is discussed in the article "Paperikone - ekosysteemi ja bioreactori" ("Paper Machine - An Ecosystem and A Bioreactor") by JM in the annual of Finnish Microbiology Society (INOCULA 2007 / 1 - unfortunately only in Finnish). Understanding of these two natures of a paper machine gives new chances for the mills: it gives the ability to forecast microbiological events inside the processes and it also give extra time to prevent problems.

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