肖尔布拉克高温大曲中细菌分离及产香研究

Isolation and Aroma-producing Study of Bacteria from Xiaoerbulake High-temperature Daqu

从肖尔布拉克酒业酱香型高温大曲中通过常温法和热处理法分离出了39株细菌,采用麸皮浸出汁培养基发酵,发现其中15株细菌的发酵液酱香味明显。将这15株细菌进行复发酵并进行蛋白酶活力的测定,显示15株菌株均有蛋白酶活力,其中有6株活力较强,分别为C1-3,C4,C8,R12,R19和R20。对这6株菌株进行基因组测序,C1-3、C4、R19和R20为枯草芽孢杆菌,C8为甲基营养型芽孢杆菌,R12为考克氏菌。对该6株菌发酵液进行气相色谱质谱分析,结果显示,6株菌检测出的物质数分别为:8种、19种、24种、15种、8种和9种。其中C1-3和R19生成的四甲基吡嗪含量较高。

39 strains of bacteria were isolated from Xiaoerbulake Jiangxiang high-temperature Daqu by normal temperature treatment and heat treatment. Fermented in wheat-extract medium, 15 of these strains produced obvious Jiangxiang flavor. The 15 strains went through fermentation process again and their protease activity were determined. All 15 strains had protease activity, and 6 of them（C1-3, C4, C8, R12, R19 and R20）had relatively high protease activity. Through 16 S rDNA sequence analysis, strains C1-3, C4, R19, and R20 were identified as Bacillus subtilis,C8 as Bacillus methylotrophicus, and R12 as Kocuria sp. Then the fermentation liquid of the 6 strains went through GC-MS analysis. The results showed that the numbers of components generated were 8, 19, 24, 15, 8 and 9, respectively, and that strains C1-3 and R19 generated more Tetramethylpyrazine than other strains.