黑色高温大曲中芽孢杆菌类群解析及其分离鉴定OA

This study employed metagenomic sequencing technology to analyze the microbial structure and function of black high-tem-perature Daqu from five regions,clarifying the composition of Bacillus groups within this context.Concurrently,the optimal isolation medi-um and temperature for the predominant Bacillus species were identified.The metagenomic sequencing results indicated that Bacillus con-stituted one of the main microbial genera in black high-temperature Daqu,with an average relative abundance of 4.89％.B.licheniformis emerged as the most common species,exhibiting an average relative abundance of 2.20％.Analysis of the metabolic pathways revealed that the growth and metabolism of aerobic microorganisms in Daqu were notably active,fostering the production of flavor and flavor precur-sor substances.Pure cultivation techniques demonstrated that the cultivable Bacillus species in Daqu comprised B.licheniformis and B.sub-tilis,accounting for 94％and 6％,respectively.When isolating B.licheniformis from Daqu,20 and 25 isolates were obtained at culture temperatures of 45℃and 50 ℃,respectively.Additionally,16 and 18 isolates were recovered from nutrient agar(NA)and tryptic soy agar(TSA)+5％horse serum media,respectively.These findings indicated that Bacillus licheniformis was the predominant Bacillus strain in black high-temperature Daqu across various regions,and it coulld be effectively isolated at culture temperatures of 45 ℃ and 50 ℃,as well as from NA and TSA+5％horse serum media.