基于磷脂脂肪酸分析技术的大曲微生物群落结构多样性研究
Studies on Daqu microbial community structure based on phospholipid fatty acid( PLFA) analysis
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摘要: 采用磷脂脂肪酸(PLFA)技术,对清香型大曲、浓香型大曲和酱香型大曲微生物群落结构及其多样性进行研究。结果表明,基于磷脂脂肪酸分析技术在不同类型大曲中共检出碳原子总数从14到20的PLFA 18种,主要包括直链饱和脂肪酸、支链饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸。大曲微生物都以真菌(18∶2ω6,9、18∶1ω9)含量为主,占脂肪酸总量的90%以上,大曲中细菌微生物主要以G+(a14∶0、i14∶0、i15∶0、a16∶0、i16∶0)为主;不同工艺大曲微生物群落结构存在明显差异,随着制曲温度的升高,大曲微生物多样性指数有下降趋势。Abstract: The community diversity of microbial in sauce-flavor Daqu,strong-flavor Daqu and light-flavor Daqu were investigated using phospholipid fatty acids( PLFA) as a culture-independent method. The results showed that according to phospholipid fatty acid( PLFA) technique,a total of 18 fatty acids with chain lengths ranging from C_14 to C_20were detected,including straight-chain PLFA,branched PLFA,monounsaturated PLFA,and the polyunsaturated PLFA. The amount of fungi dominated in the different Daqu.Specifically,gram-positive bacteria( G~+) were the main bacteria,the 18∶2ω6,9 and 18∶ 1ω9accounted for more than 90% PLFA.The correlation between the craftwork of Daqu and the microbial community structure was obvious.The community diversity was decreased as the craftwork temperature of Daqu increasing.