清香型小曲白酒生产中红曲霉的分离及发酵特性研究

Isolation of Monascus Strains from the Production Environment of Qingxiang Xiaoqu Baijiu and Study on Their Fermentation Characteristics

研究采用培养组学首次从清香型小曲白酒绿衣观音土曲和酒醅中分离出9株红曲霉,经形态学和分子生物学分析鉴定为7株紫色红曲霉和2株红色红曲霉。进一步通过耐受性实验发现,该批红曲霉最适pH值为4~5,最低可耐受pH值为3,最高可耐受乙醇浓度为25%vol,以及最适温度为30~35℃。同时,对9株红曲霉制成的红曲米糖化酶活、蛋白酶活和酯化力进行了检测,结果发现红曲T4蛋白酶活最高,红曲M2糖化酶活最高,红曲T2的酯化力最高。本研究阐明了清香型小曲白酒生产中红曲霉种类及发酵特性信息,为下步红曲霉的应用提供了理论依据。

9 strains of Monascus were isolated from the green-covering Guanyin Tuqu and the fermented grains of Qingxiang Xiaoqu Baijiu by culture omics for the first time,and 7 of them were identified as Monascus purpureus and the other 2 were identified as Monascus ruber through morphological and molecular biology analysis.Tolerance experiments revealed that the optimum growth pH of the Monascus strains was 4 to 5,the lowest tolerable pH was 3,the highest tolerable ethanol concentration was 25%,and the opti-mum growth temperature was 30℃to 35℃.Meanwhile,the glucoamylase activity,protease activity,and esterification power of the rice starter made by the 9 Monascus strains were tested.The results showed that the protease activity of Monascus T4 was the high-est,the glucoamylase activity of Monascus M2 was the highest,and the esterification power of Monascus T2 was the highest.This study has clarified the species and fermentation characteristics of Monascus in the production environment of Qingxiang Xiaoqu Bai-jiu,and has provided theoretical basis for future application of Monascus.