Department of Molecular Biology, Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju, Jeollabuk-do 561-756, Republic of Korea; Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju, Jeollabuk-do 561-756, Republic of Korea.
Fermented Food Science Division, Department of Agrofood Resource, NAAS, RDA, Wanju-gun, Jeollabuk-do 565-851, Republic of Korea.
Food Microbiol. 2016 Dec;60:73-83. doi: 10.1016/j.fm.2016.07.002. Epub 2016 Jul 2.
Nuruk, a traditional natural starter, is extensively used in the brewing of Makgeolli, one of Korea's most popular alcoholic beverages that has been recently gaining global popularity. Thus, the quality of traditional nuruk needs to be enhanced. The nuruk mycobiome greatly influences both fermentation process as well as palatability enhancement. Limitations of culture-dependent identification restrict an accurate analysis of fungal diversity and distribution in nuruks. 454 pyrosequencing of two traditional wheat-based nuruks, prepared at two representative temperature conditions revealed a total of 153 and 53 OTUs for nuruks A and B, respectively, from a total of 33,157 ITS sequences. Phylogenetic assignments indicated that nuruk A mycobiota was dominated by the genera Aspergillus and Mucorales, whereas nuruk B by Rhizomucor. Species-level identification indicated that Mucorales sp., Aspergillus candidus, and Aspergillus cibarius predominated in nuruk A mycoflora whereas Rhizomucor pusillus, Mucorales sp., and Thermoascus crustaceus in nuruk B. The alpha diversity indices suggest nuruk A mycobiota to be more diverse than that of nuruk B at almost all time points of fermentation. Resemblances of patterns of predominant species composition and succession between culture-dependent and -independent phylogenetic analysis creates the potential to reconstruct the nuruk mycobiome in vitro, which allows the establishment of a standard inoculum for scientific comparison.
糯米糕，一种传统的天然发酵剂，被广泛用于酿造韩国最受欢迎的酒类之一——马格利酒，近年来，这种酒类在全球范围内越来越受欢迎。因此，传统糯米糕的质量需要得到提升。糯米糕的真菌菌群极大地影响了发酵过程和口感的提升。基于培养的鉴定方法的局限性限制了对糯米糕中真菌多样性和分布的准确分析。对两个传统的小麦基糯米糕（在两个代表性温度条件下制备）进行的 454 焦磷酸测序，共获得了 33157 个 ITS 序列，其中 A 号和 B 号糯米糕分别有 153 和 53 个 OTUs。系统发育分配表明，A 号糯米糕真菌群主要由曲霉属和毛霉目属组成，而 B 号糯米糕则由根霉属组成。种水平的鉴定表明，毛霉目属 sp.、白曲霉和黄曲霉在 A 号糯米糕真菌群中占优势，而短小根霉、毛霉目属 sp.和嗜热毁丝霉在 B 号糯米糕中占优势。α多样性指数表明，在发酵的几乎所有时间点，A 号糯米糕的真菌群比 B 号糯米糕的真菌群更为多样化。基于培养和非培养的系统发育分析的主要物种组成和演替模式的相似性为重建糯米糕真菌菌群提供了潜力，这使得可以在体外建立标准接种物进行科学比较。
