浓香型大曲菌系、酶系的研究进展

Research Progress on Microorganisms and Enzymes in Nong-flavor Daqu

浓香型大曲是酿造浓香型白酒专用的糖化发酵剂,长期在开放性的操作环境下,定向富集了大量的微生物并产生多种酶系,形成了有利于浓香型白酒酒质的自然复合体。本文较为全面地总结了浓香型大曲中菌系、酶系的研究进展,并从其各自的研究方法入手对其进行了比较和展望。传统的菌系研究方法主要依赖于对可培养微生物的分离鉴定,该方法可以有效认知特定优良菌种的特性,但识别物种数量有限。近年来,研究较多的是利用非培养方法进行微生物物种和优势群体的解析,包括聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)、高通量测序和组学技术等。传统的酶学研究主要包括大曲粗酶液和大曲来源微生物发酵粗酶液的研究,它可用来识别大曲主要酶系,但对各类功能酶的细分及其微生物溯源尚待深入研究;目前较前沿的酶系研究是利用宏转录组学和宏蛋白组学,开展大曲的丰富酶系和优势功能酶的研究,并在此基础上进一步通过异源表达,获取大曲特有功能酶系。鉴于浓香型大曲样品的复杂性以及目前技术的局限性,使得其中微生物群落的功能与联系、酶系之间复杂关系以及共性规律还无法完全、清晰地展示。因此,在有关检验检测持续发展和酿酒行业应用需求的驱动下,相信以上关系及共性规律还将得到不断的揭示和丰富。

Nong-favor Daqu is an important fermentation starter for Nong-favor Baijiu.In a long-term and open operating environment,a large number of microbes and enzymes have been enriched in Daqu,in which a balance natural complex is formed among microbes and enzymes.This review summarizes the recent researches on microorganisms and enzymes of Nong-flavor Daqu over the years,and systematically compares their analyzing methods,so as to propose reasonable ways for future work.The traditional method on microbes relied on the isolation and identification of culture-dependent microbial,can effectively obtain characteristics of excellent microbes,but the subdivision of various functional enzymes and their microbial origin remain to be further studied.In recent years,more studies have focused on the analysis of microbial species and dominant community using culture-independent methods,including PCR denaturing gradient gel electrophoresis(PCR-DGGE),high-throughput sequencing,omics technology and so on.Most enzymes are traditionally studied with Daqu crude enzyme solution and crude enzymes solution from Daqu microbial fermentation,which can be used to identify the main enzymes in Daqu,but could not specifically and accurately identify functional enzymes.Nowadays,the main focus of enzyme is to study the abundant and dominant functional enzymes of Daqu by metabtranscriptomics and metagenomics,so as to obtain the unique functional enzyme of Daqu through heterologous expression.In view of the complexity of Nong-flavor Daqu samples and the limitations of current technologies,the functions and relationships of microbial communities,the complex relationships among enzyme systems and the common rules of microbial communities in Nong-flavor Daqu cannot be fully and clearly demonstrated.Therefore,under the driving of the continuous development of the relevant detection and testing and the application demand of the Baijiu industry,it is believed that the above relations and common laws will be constantly revealed and enriched.