小曲中产香霉菌的优选及培养条件优化

Study on optimization and culture conditions of mold in Chinese koji

以15株霉菌作为出发菌株,筛选出产香能力强的霉菌,优选产香霉菌的发酵培养基,再对优良菌株的培养条件进行优化。结果表明:Njsys-6,Njsys-45,Njsys-50 3株霉菌产香能力较强,米曲汁培养基发酵的代谢产物最丰富,酯化酶活力和总酯含量最高,分别为7.19U/mL和0.18%;试验得知Njsys-45为小曲最优添加菌,耐酒精浓度10%、最高耐温36℃、耐pH 3.6。经验证,Njsys-45能增加小曲酒的香味物质,酯化酶活力为7.18U/mL,总酯含量为0.18%。

In the study, 15 strains of molds in the laboratory were used to screen strains with strong aroma-producing. Then chose the media for mold culture, and optimized the culture conditions for strain culture. The results showed that： the Njsys-6, Njsys-45 and Njsys-50 fermentation medium were best. Rice starter liquid fermen- tation metabolite was the most abundant, the esterified enzyme activ- ity and total ester content was the highest for 7. 19 U/mL and 0.18%. Njsys-45 can resistant the highest alcohol and temperature, were 10% and 36 ℃, respectively. Njsys-45 could resistant a pH of 3.6 which had strongest acid resistance in all strains. Njsys-45 strains could improving aroma substances in Koji after proven, and the esterified enzymesc was 7.18 U/mL, the total ester was 0.18%.