Biocides

Comment

Comment by Juha Veikko Mentu on October 3, 2008 at 5:22pm

It seems that certain interest in novel, both rapid OFF LINE and automatized ON LINE methods for the control of paper machine microbiology has arisen at least in Finland. The benefits of fast activities against spoilage of raw materials, biofilm and slime problems in processes as well as immediate corrections of biocide problems is understood in many mills.

What has prevent the progress of microbiological control in the mills until now?

First of all: lack of knowledge (ref. the picture above, drawn by my son in his early years). Bacteria, moulds and yeasts are something frightening for the majority of paper mill personnel. This opinion is false: learning basic facts of microbial ecology, environmental ecology and biotechnology helps to understand the activities of microbes. This kind of knowledge is served every year on trainig courses, intended in to present microbiology to laymen of paper industry.

Another claim: " We shall wash our machines several times per year - we then clean both chemical and microbiological problems away". False again: microbiological problems very often hide inside the process and lead frequently to acute problems which force to stop the production and clean the machine - and in worsest cases, lead to severe faults of products.

We do not think that visiting our doctor a couple of times per year covers us against infectious diseases all the year, do we? Absolutely not - why then we thrust that infrequent boil-outs could prevent our machines against their "diseases"?

"Where we can catch information of novel control methods? We are not microbiologists?"

A good supply of paper industry microbiology is available nowadays, not only in scientific journals (J.Appl.Environ.Microbiology and J.IndMicrobiol.Biotech. may be the best sources of P&P microbiology today), but also on courses, blogs (like this and www.biotechtouch.blogspot.com) and elsewhere in Internet.

Focusing certain activity to be familiar with P&P microbiology isn't too hard task for those persons who are responsible for the technical and quality issues of paper and board production. It is definitely worth to do and to reserve time for it.

Back to the title of this post: great british rock group "The Moody Blues" published and album with the same title years ago. Progressive rock with jazz features (near to the heart of IM) then grew to a respective form of music all over the world on 1960's-1970's. I hope that we are now similarly stepping into a new era of control methods for paper industry microbiology today.
POSTED BY JUHA V. MENTU AT 3:46 AM 0 COMMENTS
LABELS: BIOTECHTOUCH, MICROBIOLOGY, MOODY BLUES, OFF LINE, ON LINE, PULP AND PAPER

Comment by Juha Veikko Mentu on October 3, 2008 at 5:21pm

Public interest in novel microbiological methods for paper industry is growing - not very fast (which is typical for this branch of massive industry) but sincerely.

I would like to add my last post to www.industrymicrobiologist.blogspot.com here, too, because the application of novel biocides needs certainly novel control, too: they are effective but not long-lasting (which is one target for their development!) and their optimal dosage may be very difficult to test with ordinary lab methods (= there are no biocide left anymore / biocides cannot be produced in lab conditions).

Here my post:

Comment by Helge V. Keitel on August 25, 2008 at 1:51pm

Juha, good to know about the Lappeenranta university event. Please use the Event function to promote the event. Also tell who can participate.

Comment by Juha Veikko Mentu on August 25, 2008 at 1:32pm

"Signs of Renewal in the Forest Industry - How to Combine Research and Business" 9th - 10th September 2008 at Lappeenranta University of Technology is a biannual event with a topical theme. It is arranged by Forest Industry Institute, South Carelian University of Applied Sciences, Lappeenranta University of Thechnology and OSKE. Program and registration form can be found in www.forestindustryinstitute.fi/summerschool.

I will have my presentation 9th September 15:10 - 16:15.I will add its abstract below:

"Origin and Control of Microbiological Deposits in Paper Machines

Sources of contamination shall be controlled already when receiving raw water, mineral slurries, starches and other additives into the paper mill. Paper machines are technical ecosystems with several ecological “niches”, were microbes with different origin can be adapted. Some of these sites are common in all machines, but “detective work” is needed to reveal all individual sites of microbial growth. Paper machines act also like fermentors, securing stable growth conditions for microbial species: pH, temperature, redox potential and nutrient supply are more or less constant during the drive of the machine. Microbiological analyses – traditional and novel ones – are both needed to either check the hygienic quality of incoming raw materials and products or to control the microbiological conditions in the processes. Previous task is usually performed by traditional alternatives (mostly with colony count methods) but process control needs novel, rapid methods (microscopy, ATP Assay, BIOTOUCH/PMEU technique etc.) to give so immediate responses on hazardous situations as possible. Some new ideas of ON LINE control of microbiological status and efficiency of biocide programs have also presented recently. Prevention of microbial growth in raw materials and waters of a paper machine bases on the biocide dosing programs (active compound, dosing volumes, timing and distribution of doses inside the machine as the most important topics) which shall be applied into every machine with experience. Different types of biocides work best in different situations, and issues like biocidic effect of the compound against prevailing microbial population, mode of action (fast-acting oxidizers vs. storing compounds) and the “slimicidic” (efficiency against biofilm and slime formers) properties of the compound shall therefore be taken into account. Frequent cleanings of the machines is also important - especially when the machine is suffering on severe biofilm growth. HACCP (“Hazard Analysis Critical Control Point”, most common QC tool in food industry) is worth to apply also into paper industry."

Comment by Juha Veikko Mentu on August 20, 2008 at 2:45pm

As known by microbiologists, traditional plate count methods cause bias into the biocide test results. No matter the active compounds are added to the process samples for KILL tests, final results are still derived by colony count analyses.

To have faster and more reliable evaluation (no need to dose every alternative into the process for days..weeks) a novel test method, which performes the biocide evaluation in original samples all over the test, is needed. PMEU method seems, until now, definitely to be the best choose.

Comment by Juha Veikko Mentu on August 20, 2008 at 9:43am

What should an ideal biocide be like?

* effective against a variety of microbial species

* effective in different process environments (temperature, pH, RO potential, solid concentrations etc.)

* both fast and conserving type of action

* not harmful for employers of paper machine

* not harmful for paper machine

* not harmful for products of the paper machine

* not harmful for environment

* (something else?)

As far as I know, no such ideal biocide has been developed yet. "Tailored" biocide products shall therefore be combined to fight against raw material contamination, microbial activity in large process water and pulp systems, fiofilm producers...

The rapid development of fast-acting oxidative agents (chlorine-and bromine-based compounds, PAA, ClO2 and even O3) is very promising, but they have relatively limited success as storing agents. Their broad-spectrum influence on even bacterial spores should be taken into account when planning biocide programs, which also should contain compounds to prevent biodegradation during storage periods and formation of biofilms on wet surfaces of the machine.

In some cases, activity of alternative biocides against certain hazardous bacteria are also worth to evaluate.

Comment by Helge Keitel on August 19, 2008 at 10:33pm

Juha, I suggest you open a discussion. We should ask Elias to come in to discuss about these themes.

Comment by Helge V. Keitel on August 18, 2008 at 5:14pm

Nice to see you started a new group.

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