高产开环型monacolin K红曲霉菌株的筛选及其在红曲酒酿造中的应用

该研究采用38株红曲霉菌株固态发酵制备功能红曲米，采用高效液相色谱法测定红曲米中monacolin K和桔霉素含量，筛选高产开环型莫纳可林K(monacolin K)红曲霉菌株，通过形态观察及分子生物学技术对筛选菌株进行鉴定，并将其应用于红曲酒酿造，分析红曲酒的品质。结果表明，筛选得到1株高产开环型monacolin K、不产桔霉素的菌株ABQ2，经鉴定，其为丛毛红曲霉（Monascus pilosus）。采用该菌株发酵制备功能红曲米中的monacolin K含量达到25.10 mg/g，开环率为90.5%，且桔霉素未检出。采用菌株ABQ2酿造的红曲酒酒精度为12%vol，酸度为1.91 g/100 mL,monacolin K含量为0.48 mg/mL，其理化指标均符合相关行标要求；与小曲酒相比，红曲酒中总酯含量（433.65 mg/L）极显著增加（P<0.01），其中乳酸乙酯和乙酸乙酯含量最高，高级醇类含量（145.52 mg/L）略低，主要为正丙醇、异丁醇、正戊醇、β-苯乙醇等。

Screening of Monascus spp. strain with high-yield open-loop monacolin K and its application in Hongqujiu brewing

Functional Monascus rice was prepared using 38 Monascus spp. strains by solid-state fermentation, and the contents of monacolin K and citrinin in Monascus rice were determined by high performance liquid chromatography (HPLC). The Monascus spp. strain with high-yield open-loop monacolin K was screened and identified by morphological observation and molecular biological techniques, it was further used in Hongqujiu brewing, and the quality of Hongqujiu was evaluated. The results showed that, a strain ABQ2 with high-yield open-loop monacolin K and without citrinin yield was screened, which was identified as Monascus pilosus. The content of monacolin K reached 25.10 mg/g in the functional Monascus rice fermented by the strain ABQ2, and the open-loop rate was 90.5%, citrinin was not detected. The alcohol content was 12%vol, acidity was 1.91 g/100 ml, and monacolin K was 0.48 mg/ml in Hongqujiu fermented by the strain ABQ2, its physicochemical indexes were compliance with relevant industrial standards. Compared with Xiaoqujiu, the content of total esters (433.65 mg/L) in Hongqujiu was extremely significantly increased (P＜0.01), in which the contents of ethyl lactate and ethyl acetate were the highest, and the content of advanced alcohols (145.52 mg/L) were slightly lower, mainly n-propanol, isobutanol, n-amyl alcohol, β-phenylethanol, etc.