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.

2 comments:

Helge V. Keitel said...

Hello Juha Mentu, this is a very good start. Your blog opens up a new communication channel when we talk Biotouch opportunities and services on a global scale.

Biotouch is a global service. This is an cost-effective way to distribute information to potential partners and industrial clients.

Elias said...

To Juha Mentu, the accumulation of process management information is essential. We as microbiologists have developed skills and technologies for getting an improved view on the unseen microbe world. All macroscale phenomena reflect the small events that take place in the microbial ecosystems. These ecosystems thus continuously interact with the process macroscale. This resembles the molecular communication between human body and the microflora, which also forms a complex ecosystem. The understanding on the microbe life has to be cultivated. Thank you for opening up the new forum! Elias Hakalehto, Docent in Biotechnical Microbe Analytics