Optimization research of fermentation mediums for antimicrobial metabolites producing strain Propionibacterium shermanii

The fermentation medium was optimized to reduce the medium cost and promote the antimicrobial metabolites production of Propionibacterium shermanii by simple factor experiment and response surface methodology.The results showed that the yeast extract and tryptone of original medium could be replaced by the corn steep liquor power and soy peptone.According to Box- Behnken design and response surface methodology, the optimal medium were as follows: glucose 8.2g / L, soy peptone 5.1g / L, and corn steep liquor 12.7g / L. After medium optimization, the theory value of antimicrobial activity was 29.5AU / m L, and was improved by 57.2%. The actual operation of the experiment turned out to be 29.4 AU / m L, and the medium cost was reduced.