酱香白酒酿造环境曲霉的分离及Aspergillus hennebergii酶分泌胁迫条件

Isolation of Aspergillus from Jiangxiang Liquor Fermentation Environment and Enzyme Secretion Stress Conditions of Aspergillus hennebergii

以茅台镇酱香白酒酿造过程关键环节样品为载体,对曲霉的生态结构分布进行分析;以新鲜麸皮为培养基模拟固态发酵方法对影响筛选优势菌株Aspergillums henneberguii的生长及分泌糖化酶、蛋白酶的主要发酵胁迫条件进行了分析。结果分离得到曲霉103株,分别鉴定为10个种属种,即A.niger、A.oryzae、A.terreus、A.tubingensis、A.flavus、A.henneberguii、A.fumigatus、A.niveus、A.candidus和Monascus;发酵基质初始水分在50%和初始p H在3.5~4.0条件下有利于Aspergillums henneberguii的生长和酶的分泌;Aspergillums henneberguii的适宜生长温度范围为30~35℃,酶分泌温度为32~35℃;高乙醇体积质量（〉8%）对Aspergillums henneberguii的生长和产酶存在抑制,低乙醇体积质量（2%）反而有利于其生长和酶的分泌;（NH4）2SO4有利于Aspergillums henneberguii糖化酶的分泌,Na NO2和酵母浸膏有利于其生长和蛋白酶的分泌;乳糖和麦芽糖对Aspergillums henneberguii的生长和产酶有利,山梨糖、蔗糖、果糖可促进菌株糖化酶的分泌;单独添加硫酸钠有利于Aspergillums henneberguii的生长和酶的分泌;新鲜麸皮富含碳源、氮源、无机盐、微量元素等,为Aspergillums henneberguii菌体生产及制酶的优质天然载体。Aspergillums henneberguii的应用可满足传统固态白酒酿造过程的双边发酵和风味形成机制需求。

The ecological distribution of Aspergillus in the samples obtained at the key points of Jiangxiang liquor fermentation process in Maotai village and the effect of solid fermentation simulated by fresh bran medium on the growth of predominant strain Aspergillums hennebergii and the main stress conditions of glucoamylase and protease secretion were analyzed in this paper. One hundred and three strains were obtained and identified as A.niger,A.oryzae,A. terreus,A.tubingensis,A.flavus,A.hennebergii,A.fumigatus,A.niveus,A.candidus and Monascus,respectively. The suitable conditions for the growth and protease secretion of Aspergillums hennebergii were 50% water content of the fermentation substrate and the p H value of 3.5-4.0. The suitable growth temperature of Aspergillums hennebergii was 30~35 ℃,whereas the suitable enzyme secretion temperature was32~35 ℃. High alcohol contents（8%,v/w）inhibited the growth and enzyme secretion of Aspergillums hennebergii,while low alcohol contents（2%,v/w）,lactose,and maltose promoted its growth and enzyme secretion. The salt of（NH3）4SO4and Na NO2 and yeast could promote its growth,glucoamylase and protease secretion. Moreover,sorbose,sucrose and fructose could promote its glucoamylse secretion. The individual addition of sodium sulphate could promote its growth and enzyme production. Fresh bran,which was rich in carbon source,nitrogen source,inorganic salts and trace elements,could provide high-quality natural carrier for Aspergillums hennebergii growth and enzyme production. The application of Aspergillums hennebergii can satisfy the need of bilateral fermentation and flavor forming mechanism in traditional solid fermentation of liquor.