PCR-DGGE技术监测自然发酵葛根中微生物菌群动态变化

Dynamic Changes of Microbial Community in the Process of Natural Fermentation of Puerariae lotaba Monitored by PCR-DGGE

采用自然堆积发酵对葛根进行预处理,处理后葛根总异黄酮的提取量提高了5.7%左右。随后,分别采用传统平板法和PCR-DGGE技术,对发酵过程中不同时期微生物菌群的变化进行分析,从而筛选出发酵中起主要作用的微生物。结果表明,自然发酵过程中的细菌呈升高-降低-再升高的变化趋势:升温期明显增多,高温期有所下降,降温期再次增多;真菌的数量在整个发酵过程中都呈持续升高的趋势。发酵过程中起主要作用的微生物也被初步确定,它们分别是地衣芽孢杆菌、桃色欧文氏菌、芽孢杆菌属、枯草芽孢杆菌、不可培养细菌、爪哇青霉、黑曲霉、溜曲霉、米根霉和不可培养曲霉。

In this study,the extraction yield of total isoflavones from Puerariae lotaba increased by 5.7% after pretreated with naturalcompost fermentation. After that,in order to determine the microorganisms playing a major role in this fermentation,the dynamic changesof the microbes in the process of natural fermentation of P. lotaba powder were analyzed using traditional flat culture method and PCR-DGGEtechnology respectively. The results showed that the number of bacteria showed an ＂increase-decrease-increase＂ trend in the whole fermentationprocess ：increased significantly in the temperature-rising stage,then decreased slightly in the thermophilic stage,and finally rose again inthe temperature-cooling stage,but the number of fungi presented a continuous increase trend. Besides,several microorganisms isolated fromP. lotaba were initially identified to have positive effects on improving the extraction yield of total isoflavones,and these microbes included ：Bacillus licheniformis,Rhizoctonia solani,Bacillus,Bacillus subtilis,non-cultivable bacteria,Penicillium japonicum,Aspergillus niger,Aspergillus,Asparagus,and non-cultivable Aspergillus.