separate bacteria form a fermentor broth

[Fb2003]

Good day all,

 

I'm a student and we are currently working on a project involving sterile filtration. The idea was to separate bacteria form a fermentor broth flow. Because it had to be a solution for filtering continous, I thought of a tangential crossflow filter. Luckily we had one at school, a labscale minitan TFF form the manufacturer millipore. I used the 0.45 mircometer pore membranes that where still in tact (4 membranes) and ran some tests on the fermentor broth.

 

Fermentor broth contains:

 

- LB medium

- E coli (+enzyme)

- p-phenylenediamine (*simulation)

- 4-aminophenol (*simulation)

- antifoam

 

*The 2 simulation substances are there to simulate the products of L-&D-phenyalamine + an enzyme.

 

After doing some tests, the sterile filtration seemed to go well. But after getting some strange results, I opend the minitan and came to the conclusion the membranes where damaged. Most likely by one of the used simulation substances, resulting in brittle part of the membranes.

 

The membranes can't be ordered form millipore becauce the hardware for the system has been obsoleted, since 31 March, 2000. And ordering a complete new TFF system won't be a good option, because I only have 2 weeks left for running my tests. This is why I ask for help, I need a lab-scale method for separating E coli bacteria form a (continuous) fermentor broth. But this methode should also be up scalable to a continous industrial method (in theory).

 

I would really appreciate a good reaction. Or some spare minitan 0.45 micrometer membranes .

 

Thank you!!

 

Frank B.

[KAZU]

I don't know if this helps, but people in the micro brewing industry use a method called Flocculation. http://www.crc.dk/flab/newpage4.htm is a good link that explains the process. This process has also been used for e coli http://www.springerlink.com/content/r81802m228k574q6/

 

Kazu