高温大曲中高产四甲基吡嗪芽孢杆菌的分离鉴定及发酵条件优化

该研究从高温大曲中分离筛选产四甲基吡嗪（TTMP）芽孢杆菌，采用细胞形态学观察、生理生化试验及分子生物学技术对高产四甲基吡嗪菌株进行鉴定，并优化四甲基吡嗪产量最高菌株的发酵条件。结果表明，经初筛从高温大曲中分离出20株产四甲基吡嗪芽孢杆菌（编号为WH1～WH20），经过复筛得到四甲基吡嗪产量较高的菌株WH7、WH10和WH20。其中菌株WH7和WH20被鉴定为副淀粉芽孢杆菌（Bacillus paramycoides），菌株WH10被鉴定贝莱斯芽孢杆菌（Bacillus velezensis）。菌株WH10的最佳发酵条件为：前发酵温度37 ℃、前发酵时间72 h，后发酵温度60 ℃，后发酵时间20 h，初始pH值6.5，铵盐添加量4 g/L。在此优化条件下，四甲基吡嗪产量为728.38 mg/L，比优化前提高了167%。

Isolation and identification of high-yield tetramethylpyrazine Bacillus from high-temperature Daqu and optimization of fermentation conditions

The tetramethylpyrazine (TTMP) producing Bacillus were isolated and screened from high-temperature Daqu, the high-yield TTMP strains were identified by cell morphological observation, physiological and biochemical tests, and molecular biological techniques, and the fermentation conditions of the strain with the highest TTMP yield were optimized. The results showed that 20 strains of TTMP producing Bacillus were isolated from high temperature Daqu after preliminary screening (numbered as WH1-WH20) and the strains WH7, WH10 and WH20 with higher TTMP yield were obtained after rescreening. Strains WH7 and WH20 were identified as Bacillus paramycoides, and strain WH10 was identified as Bacillus velezensis. The optimum fermentation condition of strain WH10 were as follows: pre-fermentation temperature 37 ℃ and time 72 h, post-fermentation temperature 60 ℃ and time 20 h, initial pH 6.5 and ammonium salt addition 4 g/L. Under the optimal conditions, the TTMP yield was 728.38 mg/L, which was 167% higher than that before optimization.