In the pulp and paper company that I work in, samples from paper, water and pulp from the paper machine gave information about existing spores of Presumptive Bacillus cereus.
Our paper is used for food packaging manufacture, so the presence of spores in it is unacceptable.
Can you give me an advice on how to deal with this problem? Is there a way to remove spores from the machine?
Because I am a little bit familiar with paper machines, I can imagine that it is not an easy task to reduce bacterial contamination in this production system. In my opinion, you have to determine the sources of contamination and try to eliminate them. Without a detailed description of the production line and all inputs and outputs, a reliable solution cannot be prepared.
Regards
Vit
Mister,
We took samples from the folllwinf points:
1. Industrial water (leaking from a hose).
2. Head box (where the paper travels before it is formed as a sheet).
3. White water tank (from below the sieves).
4. Tank for broke pulp.
All samples gave a result of 1.8-2.9 logCFU/ml aerobic bacteria in the samples.
We used the 3M PetriFilm kit.
Cultivation: 37 degrees Celsius/24h
Papermaking process is dirty and controls limit but do not eliminate microbial presence. You'll have bacterial and fungal spores and you're not going to eliminate them in normal process.. Bacillus cereus is ubiquitous in food and manufacturing environments and transfer from paper packaging is reportedly a trivial exposure. If you that concerned - use gamma.
Article Transfer of Bacillus cereus Spores from Packaging Paper into Food
Thank you!
You mean gamma radiation?
Where in the process should I apply it?
And what if I use ultrasound, for example, and apply it to the Broke pulp tank (~1000 m^3)?
Yes gamma irradiation. This will be an external service (e.g. https://www.steris-ast.com/services/gamma-irradiation/) applied to the finished paper product. It is not a capability you'd bring in house.
Ultrasound will not reliably eliminate bacterial; spore viability.
Please help me understand - is "unacceptable" based on a regulatory requirement, corporate safety policy, perception or what?
The results are in compliance with the standart that the laboratory works with. But are not suitable for our corporate safety policy.
Endospores have been found in many paper products, especially those including recycled paper as a source. This might be eliminated, or treated before use. Otherwise treatment including chlorination along the path might help. Heating can kill bacteria, but the endospores are resistant until above 121 degrees C. So a possible technique is to to heat the pulp flow and then give it time for the spores to germinate. After they have germinated heat can be used again to kill the vegetative bacteria. Less heat is needed. Basically you need to find a way to trick the spores and then kill them when they are vegetative. These possible solutions do require you to know if the spores are entering the system as spores or entering as vegetative bacteria and sporulating along the system.
Ivan - please note this report. Article Description of heterotrophic occurring in paper mills and pa...
B. cereus is common - perhaps the ,most common spore former - in paper making systems and paper. It is not feasible to sterilize pulp by Robert's suggestion (Tyndalization) and even if possible, the production system would rapidly recontaminate. Paper products used in medical applications are sterilized post-production by gamma or Ethylene oxide treatment. If you require sterility for such application, those are you choices. If not, suggest you challenge the corp standard as impractical. Own your science please
Thank you, people, you motivate me to think and look for ways to getting the job done! The problem is that the tank we must sanitize has a volume of 1250 cubic meters. Perhaps the ultrasound technique is the key to success in fulfilling this task, but I don't know if we can find a device big enough for covering 1250 m^3 tank...
- Badges
- Science topic
- Similar topics
- Automotive Engineering
- Machines