The microbial species I am working with, are psychrophile, they take about 6 months to grow in liquid media with max. OD (600nm) of 0.2. However, they grow and produce EPS (as biofilm) on an agar plate much faster (2-3 weeks).
For EPS isolation, however, the method of agar plate culturing may not be valid since the sample may get contamination from agar itself. I used glass substratum in liquid media but, they are not growing/attaching to the same. Could anyone suggest any solution to it?
Dear Shhipra,
Our research has focussed on biofilm-forming Pseudomonas isolates, some of which we recovered from contaminated meat and were psychrophiles, though mostly we have been working with a P. fluorescens strain which over-expresses cellulose.
We have grown these up on nitro-cellulose filter disks (2.5 cm diameter, 20 µm pore size) placed on agar plates for 2-3 days to produce good colonies, then lifted
them off the plate and incubated for a further 1 - 5 days to assess survival under water-limiting conditions.
Perhaps you could use this technique to isolate sufficient bacterial biomass to allow you to extract and analyse EPS which is not contaminated with agar? You could try glass-wool or plastic filters if you did not want to use nitro-cellulose disks as we did.
Regards, Andrew.
Dear Andrew, thanks for your suggestion. This method has been tried in our lab. It gives the growth of microbes but do not facilitate enough EPS production as required for the study.
As Andrew J. Spiers suggested, perhaps plastic. Nylon mesh filters are inert and it may be easier to remove the EPS than from nitrocellulose. Try Pall or Steriltech.
Back when blot hybridization was more common, it was very cost-effective to purchase large roles of nylon mesh for applications like this.
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts