【目的】荧光定量PCR法具有特异性高、灵敏度高等优点,在定量复杂环境中微生物数量方面得到广泛应用。本文采用荧光定量PCR方法对固态白酒发酵过程产土味素链霉菌进行定量分析并验证其准确性。【方法】通过优化大曲和酒醅中微生物基因组提取方法,并建立相应的大曲和酒醅两种基质条件下的荧光定量PCR标准曲线,并对方法的精度和准确度进行验证分析。采用荧光定量PCR方法对大曲和酒醅中产土味素链霉菌进行定量分析。【结果】结果表明大曲中产土味素链霉菌数量在10^5数量级,并且清茬曲中此类链霉菌数量最高。酒醅发酵起始阶段产土味素链霉菌数量在10^4数量级,而后随着发酵的不断进行,酒醅中此类链霉菌数量有所减少。【结论】荧光定量PCR方法能够对白酒固态发酵过程中产土味素链霉菌准确进行定量分析,对采用此方法定量其他微生物具有借鉴意义。
[Objective] The real-time PCR, with high specificity and high sensitivity, has been widely applied in quantifying microbial quantity in complex environments. We used this method to quantify TDMTDL (trans-1,10-Dimethyl-trans-9-decalol) producing microbes during the liquor brewing proecss. [Methods] Through the optimization of DNA extraction method for Daqu and fermented grains, we established two real time-PCR standard curves for Daqu and fermented grains respectively. The precision and accuracy of this method were verified. The real-time PCR method was applied to quantify the Streptomyces which produced TDMTDL in Daqu and fermented gains. [Results] The results showed that TDMTDL producing Streptomyces number was 10^5 orders of magnitude in Daqu and the number was highest in Qingcha among three kinds of Daqu. In the initial stage of fermentation, the microbial number was 10^4 orders of magnitude. Along with the continuous fermentation, the number of Streptomyces decreased. [Conclusion] Real-time PCR could quantify earthy odor producing Streptomyces in liquor significance of quantify other microbes in liquor brewing process successfully, this work also had brewing process.