Joseph Junior

Apart from adding anti-foam agents, you can recycle the broth (a small fraction) and spray on the top surface. It may break the bubbles in the reactor.

Thanks

Chandan

In my opinion, it is better to think about why the foam is produced at the end of fermentation.

There are several reasons for the foam formation. Various substances produced by growing micro-organisms enter the culture medium and promote foam formation. However, the most common reason for foam formation at the end of cultivation is the depletion of the substrate and the onset of autolysis of microbial cells, which occurs in response to the lack of a carbon source in the environment.

Regards

Vit

Dear Joseph,

I found the attached table about chemical, mechanical and physical methods to fight foam (in German though). Maybe one or a combination of multiple methods might help.

Kind regards

Michael

I have overcome this situation with adding few drops of peanut oil as and when foam starts to form ; its been effective so far.

D M NAVEEN Giri Use oil with care! It has a major negative effect on gas-liquid mass transfer. There are commercial antifoams available with much lower effect.

Yes , Van Der Lans thats a good caution . I usually come across foam at a scske of 100 ltr and above capacity fermentation trials; few drops of peanut oil do the magic . But yes if its at a 500 ml or below scale - this could be sn issue.

D M NAVEEN Giri You might test it to be sure. I used a few drops of octanol in 600 ltr of water and it had a major influence on coalescence (all small, christmas ball formed bubbles). Already drops of oil may spread on the surfaces in a monomolecular layer reducing mass transfer coefficient up to a factor of 10.