六神曲发酵过程中微生物群落结构研究

Investigation of microbial community involved in fermentation of Massa Medicata Fermentata

该文研究了采用同一发酵工艺的优化和部颁2组处方六神曲发酵过程中的微生物种类、优势物种及种群变化趋势,旨在明确六神曲发酵过程中的优势微生物种群,探寻六神曲药效物质来源。在规范发酵工艺的基础上,采用筛选优化组方和部颁标准组方制备六神曲,分别利用8种不同培养基分离培养和高通量DNA测序技术分析了六神曲发酵过程中的5个时间点(0,17,41,48,65 h)样品中真菌和细菌的群落结构及生长过程。研究结果显示,2组处方的六神曲发酵初始阶段样品中真菌的物种多样性较高,优势类群为曲霉属。随着发酵进程,扣囊复膜酵母Saccharomycopsis fibuligera和米根霉Rhizopus oryzae自发酵起点后17 h即迅速上升为优势物种,直至发酵终点,而其他物种则自17 h被抑制在较低水平。发酵初始样品中细菌的物种多样性也较高,优势类群为肠杆菌属Enterobacter。进入发酵后17 h阴沟肠杆菌Enterobacter cloacae、戊糖片球菌Pediococcus pentosaceus、阪崎肠杆菌Cronobacter sakazakii等优势种数量快速增长,物种多样性降低。研究结果将为推进六神曲纯培养微生物发酵工艺提供科学依据。

This study aimed to clarify the microbial diversity,dominant species and the change of community structures in the fermentation of Liushenqu(Massa Medicata Fermentata),and explore the material foundation of its pharmacodynamics effect.On the basis of standardizing the fermentation process,Massa Medicata Fermentata was prepared by screening and optimizing the recipes and the standard formula issued by the Ministry.The community structure and growth process of fungi and bacteria in the samples at five time points(0,17,41,48,65 h)in the fermentation process of Massa Medicata Fermentata were analyzed by using isolation and culture of eight different media and high-throughput DNA sequencing technology.The results indicated that the samples of the two recipes pre-sented high microbial diversity at the initial fermentation stage,with Aspergillus spp.as the dominant species.As the fermentation process goes forward,Saccharomycopsis fibuligera and Rhizopus oryzae soon became dominant species from 17 h after fermentation commencement point to the fermentation end,while the other species were inhibited at a lower level from 17 h.The species diversity of bacteria in the initial fermentation samples was also high,and Enterobacter was the dominant species.Enterobacter cloacae,Pediococcus pentosaceus and Cronobacter sakazakii became dominant bacterial species 17 h after fermentation commencement,while the species diversity was decreased.Our results will be a scientific basis for promoting the fermentation process of Massa Medicata Fermentata by using pure microbial cultures.