Monday, November 7, 2011
Capri Ballroom (Marriott Marco Island)
As microbial application lab we support both our yeast extract and peptone business. During customer projects we frequently find that initial material qualifications are performed on the separate products. We feel that in order to fully explore the potential of peptones and yeast extracts it is essential to co-test them, taking into account how they influence each other. The development of non-animal nitrogen sources for recombinant expression in E. coli using 4 strains (two model strains and two production strains) gave us the first complete data set. Though the set was somewhat limited it did show the importance of testing all yeast extract-peptone combinations.
To better demonstrate this we tested the growth of 13 more strains, testing yeast extracts and peptones separately as well as in all the possible combinations. Screening all options (49 to 161 combinations per microorganism) yielded on average 10% more biomass over just using the best individual peptone with the best individual yeast extract.
We developed a method that within the same set of possible peptone-yeast extract combinations only required the testing of 21% of the options, but still yielding on average 97% of the maximum possible result.
Using this type of screening we are continually developing full nitrogen sources for a wide range of microorganisms.