高温大曲中产吡嗪芽孢杆菌的分离鉴定及发酵产物分析

Isolation and identification of pyrazine-producing Bacillus from high-temperature Daqu and analysis of its fermentation products

该试验从高温大曲中筛选产吡嗪芽孢杆菌(Bacillus),通过形态观察及磷脂脂肪酸(PLFA)分析对其进行鉴定,并采用发酵试验分析其代谢产物。共筛选出3株芽孢杆菌,即菌株B_1、B_2、B_3。经分析鉴定后得出:菌株B_1为蜡样芽孢杆菌(Bacillus cereus);菌株B_2和B_3为萎缩芽孢杆菌(Bacillus atrophaeus)。3株菌发酵产物分析结果表明,在液态发酵条件下3株菌发酵产吡嗪,其中菌株B_2和B_3发酵产物中吡嗪相对含量较高,均>60%;固态发酵条件下生成吡嗪前体物质3-羟基-2-丁酮,且发酵产物中相对含量均>75%。表明这3株芽孢杆菌对酱香型白酒风味物质的产生有着一定的影响。

The pyrazine-producing Bacillus was screened from high-temperature Daqu and identified by morphologic observation and phospholipid fatty acid （PLFA） analysis. Its metabolites were analyzed by fermentation tests. Three strains of Bacillus were screened and named Bl, B2 and B3, respectively. The strain B1 was Bacillus cereus, strains B： and B3 were Bacillus atrophaeus. The results of fermentation products analysis of three strains showed that the three Bacillus could produce pyrazine under the conditions of liquid fermentation, and the pyrazine relative content in strains B2 and B3 fermentation products were high （more than 60%）. The pyrazine precursor substance 3-hydroxy-2-butanone were produced under the con- ditions of solid fermentation, and relative content were more than 75% in the fermented products, which indicated the three strains Bacillus had a certain effect on flavor substances production in Moutai-flavor Baijiu.