摘要
为分析不同发酵温度对大曲品质的影响,以同一批制曲原料进行中温和高温发酵,将两类成品大曲作为研究对象,全面比较微生物群落结构、酶活及挥发性化合物差异.利用高通量测序技术测定大曲细菌和真菌群落结构,并利用顶空固相微萃取(HS-SPME)结合气相色谱质谱(GC-MS)测定大曲挥发性化合物.结果表明,发酵温度对大曲细菌群落影响更大,泸州高温曲的细菌和中温曲相比,芽孢菌属(Bacillus)相对丰度显著上升,而乳杆菌属(Lactobacillus)和魏斯氏菌属(Weissella)显著下降.而高温曲的真菌仅曲霉属(Aspergillus)相对丰度显著高于中温曲.随着温度对微生物群落结构的改变,使得酶活和挥发性物质也存在显著性差异.从酶活结果来看,高温曲的液化酶和糖化酶显著低于中温曲(P<0.05).从挥发性化合物来看,高温曲的挥发性化合物更为复杂,其中醛类化合物含量显著高于中温曲(P<0.05),结合正交偏最小二乘判别法(OPLS-DA)分析,发现4-乙烯基愈创木酚、异戊酸、异戊醛、2-戊醇、二甲基三硫和2-甲基丁醛可能是泸州高温曲和中温曲的重要差异化合物.本研究表明温度作为工艺要点能够影响大曲微生物群落结构及酶系,进而影响大曲挥发性化合物成分,结果可为科学化制曲提供理论基础.
To investigate the effect of fermentation temperature on the quality of Daqu,two types of Daqu were fermented at medium and high temperatures using the same raw materials and differences in microbial community structure,enzyme activity,and volatile compounds were comprehensively analyzed.Highthroughput sequencing was used to analyze bacterial and fungal community structure,and volatile compounds were identified using headspace solid-phase microextraction combined with gas chromatography mass spectrometry.The results showed that fermentation temperature had a significant effect on the Daqu bacterial community.The relative abundance of Bacillus was significantly higher in high-temperature than in mediumtemperature Daqu,and the relative abundance of Lactobacillus and Weissella was significantly lower.Among the fungal communities,only the relative abundance of Aspergillus was significantly higher in the hightemperature than in the medium-temperature Daqu.There were significant differences in enzyme activity and volatile substances between the high-and medium-temperature Daqu.Amylase and glucoamylase activities were significantly lower in the high-temperature than in the medium-temperature Daqu.Volatile compounds were more complex in the high-temperature than in the medium-temperature Daqu,and the aldehyde compound content was significantly higher in the high-temperature than in the medium-temperature Daqu.Orthogonal partial least-squares discrimination analysis revealed that 4-vinylguaiacol,isovaleric acid,isovaleraldehyde,2-pentanol,dimethyltrisulfide,and 2-methylbutane aldehyde may be significant compounds that can distinguish Luzhou high-temperature and medium-temperature Daqu.The results show that fermentation temperature has significant effects on microbial community structure,enzyme activity,and volatile compound composition in Daqu,thereby providing a theoretical basis for scientific Daqu-making.
作者
冯佳婷
陆震鸣
时伟
肖辰
张晓娟
柴丽娟
王松涛
沈才洪
史劲松
许正宏
FENG Jiating;LU Zhenming;SHI Wei;XIAO Chen;ZHANG Xiaojuan;CHAI Lijuan;WANG Songtao;SHEN Caihong;SHI Jinsong;XU Zhenghong(School of Biotechnology,Jiangnan University,Wuxi 214122,China;National Engineering Laboratory for Cereal Fermentation Technology,Jiangnan University,Wuxi 214122,China;School of Pharmaceutical Science,Jiangnan University,Wuxi 214122,China;National Engineering Research Center of Solid-State Brewing,Luzhou 646000,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2021年第3期760-767,共8页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(31901117)资助。
关键词
大曲
温度
酶活
挥发性化合物
微生物群落结构
Daqu
temperature
enzyme activity
volatile compound
microbial community structure
