关键词: ε聚赖氨酸(εPL);培养基;响应面分析;优化

Abstract:

PBCCD response surface methodology was applied to optimize the 6 major compounds of the εpolylysineproducing fermentation medium(M3G)for Streptomyces sp.FEEL1. PB experiment showed  yeast extract, K2HPO4 and MgSO4 played important roles for εPL production. Combining with the results of the steep ascent test and the central composite design, the optimum concentrations of factors were determined as follows: glucose 50 g/L, yeast extract 7.54 g/L, (NH4)2SO4 5 g/L, KH2PO4 1 g/L, K2HPO4 2.48 g/L, MgSO4 2 g/L, ZnSO4 0.03 g/L,FeSO4 0.03 g/L. Under such condition, the concentration of εPL in shake flask increased to 1.62 g/L. On the basis of above result, singlefactor experiment was employed to optimize the trace elements ZnSO4 and FeSO4. ZnSO4 showed no influence on the production of εPL while 0.06 g/L of FeSO4 could increase the production of εPL to 1.73 g/L, which was 57.2% higher than that in M3G medium. The εPL yield reached to 876 g/L in 5L fermenter by controlling pH, which was increased by 41.1 % compared to that in M3G medium.

Key words: εpolylysine(εPL), culture medium, response surface methodology, optimization