Hi everyone,
before I start with my fermentation experiemtns, I wanted to do the controls. I esterilized the flasks (120C, 1 hr), prepared my pea solutions and then pasteurized them (80C, 20 min). The next day, they all had separation of phases, foam, gas and a strong fermented smell. I am guessing I have some spores in my pea isolate (microbiology counting not ready yet).
So my question is: How can I avoid this contamination? I read about the Sodium Azide (NaN3) but I have some concerns: it is not only very poisonous but the N in it could affect my protein determination (and may be my Degree of Hydrolysis determination) later on.
Do you have any recommendations what could help?
Thank you in advance.
Best,
Veronica
If the contamination is caused by spores, the solution may be repeated pasterization. After first pasterization let the flask to stay for 8 to 10 hours. During the time the pea solution will cool and spores start to germinate, after this period perform the pasterization again. The second pasteurization should kill the germinated spores. The time intervals should be optimized by you.
Good luck!!
Regards
Vit
How to avoid contamination in the microbiology laboratory: The other source of microbial contamination are water that is used in the systems so environmental monitoring is done in order to reflect the state of control of the faculty. Effort should be made to avoid carry over contamination : use filter tips or positive displacement tips to prevent aerosol transfer from the sample into the pipette body, and again to the next sample.Always change the pipette tip after each sample.. It is better to avoid contamination than trying to clear it.
https://en.wikipedia.org/wiki/Tyndallization
"Tyndallization essentially consists of heating the substance to boiling point (or just a little below boiling point) and holding it there for 15 minutes, three days in succession."
Dear Verónica García Arteaga
- Personnel hygiene must be maintained at a high standard.
- All employees whose actions can have an impact on the product's quality must undergo ongoing training, which includes hygiene guidance.
- All entering the manufacturing area should put on protective clothing that is suitable for the tasks at hand.
- Direct interaction between the operator's hand and exposed objects, or any part of the equipment that comes into contact with the product, should be avoided.
- Access to production areas must be monitored to ensure that only qualified staff have access.
Further referecne
https://learnaboutgmp.com/aseptic-techniques/prevention-and-control-of-microbial-contamination-for-pharmaceutical-products/
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