摘要
用酪素平板法从高盐稀态酱醪中筛选出56株蛋白酶活性较好的菌株,牛津杯法复筛后制曲测定酶活性,得到淀粉酶活性最高的菌株CS1.11、蛋白酶活性最高的菌株CS1.13及纤维素酶活性最高的菌株CS1.17;16S rRNA序列测定结合形态学分析,CS1.11、CS1.13、CS1.17分别鉴定为贝莱斯芽孢杆菌(Bacillus velezensis)、甲基营养型芽孢杆菌(B.methylotrophicus)、枯草芽孢杆菌(B.subtilis);分别将3株实验菌与对照菌枯草芽孢杆菌CS1.03单独进行制曲后盐卤发酵,发现CS1.13发酵酱油氨态氮质量浓度最高,为5.12 g/L,CS1.11发酵酱油还原糖质量浓度最高,为27.20 g/L,与其酶活性结果一致,4株菌对酱油总酸含量影响不大;顶空固相微萃取气相色谱-质谱联用内标法定性及定量分析发酵酱油发现,3株实验菌与对照菌均具有产生吡嗪类物质及其前体乙偶姻和2,3-丁二醇的优势,且3株实验菌优于对照菌;吡嗪类物质能赋予酱油良好的风味及健康因子,是芽孢杆菌酱油发酵的特征风味物质。筛选自高盐稀态酱醪的芽孢杆菌CS1.11、CS1.13、CS1.17有促酱醪发酵、丰富酱油风味、增进健康因子的潜力,具备良好的应用前景。
A total of 56 strains with high protease activity were isolated from high-salt liquid-state moromi(soy sauce mash)by the casein plate method.Among these,the strain CS1.11 with the highest amylase activity,CS1.13 with the highest protease activity and CS1.17 with the highest cellulase activity were selected by the Oxford-cup method.According to the 16S rRNA gene sequence analysis and morphology,CS1.11,CS1.13,and CS1.17 were identified as B.velezensis,B.methylotrophicus and B.subtilis,respectively.The three strains and the control strain B.subtilis CS1.03 were separately subjected to salt brine fermentation after koji-making.It was found that the fermented soy sauce inoculated with CS1.13 had the highest ammonia nitrogen content(5.12 g/L),and the fermented soy sauce inoculated with CS1.11 had the highest reducing sugar content(27.20 g/L).The results were consistent with the strains’enzymatic activities.In addition,the four strains had little effect on the total acid content of soy sauce.All the fermented soy sauce samples were qualitatively and quantitatively analyzed by solid-phase microextraction-coupled to gas chromatography-mass spectrometry(SPME-GC-MS)using the internal standard method.It was found that all four strains were advantageous for producing pyrazines and their precursors(acetoin and 2,3-butanediol),the three test strains being superior to the control strain.Pyrazines could impart a good flavor and health factors to soy sauce,and were the characteristic flavor substances of fermented soy sauce inoculated with Bacillus spp.Bacillus strains CS1.11,CS1.13,and CS1.17,thanks to their potential to promote moromi fermentation,enrich the flavor of soy sauce and increase health factors,will hold great promise for application in soy sauce production.
作者
吴博华
蒋雪薇
张金玉
阮志强
梁胜男
陈永发
周尚庭
WU Bohua;JIANG Xuewei;ZHANG Jinyu;RUAN Zhiqiang;LIANG Shengnan;CHEN Yongfa;ZHOU Shangting(School of Chemistry and Food Engineering,Changsha University of Science&Technology,Changsha 410114,China;Hunan Provincial Engineering Technology Research Center for Condiment Fermentation,Changsha 410600,China;Jiajia Food Group Co.Ltd.,Changsha 410600,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2021年第6期134-141,共8页
Food Science
基金
湖南省自然科学基金面上项目(2018JJ2421)
湖南省调味品发酵工程技术研究中心开放基金项目(2018GCZX05)。
关键词
芽孢杆菌
促酱醪发酵
牛津杯法筛选
蛋白酶活性
吡嗪类物质
Bacillus spp.
promoting moromi fermentation
screening by Oxford-cup method
protease activity
pyrazines
