Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
Jiangsu King's Luck Brewery Co., Ltd., Huaian 223001, China.
Int J Food Microbiol. 2021 Jan 16;337:108951. doi: 10.1016/j.ijfoodmicro.2020.108951. Epub 2020 Nov 4.
Pit mud microbiota plays a key role in flavour production for Chinese strong-aroma type liquor. However, the pit mud microbiota cannot be cultured in laboratory. In this study, an oligotrophic medium with acetate as carbon source was used to enrich pit mud microbiota. The 16S rRNA gene amplicon sequencing was applied to examine the microbial dynamics of the enrichment consortia. Both methanogens and bacteria were simultaneously enriched. Euryarchaeota, Bacteroidetes and Firmicutes were the top 3 enriched phyla, and 31 genera were successfully enriched. More specifically, 11 genera (65%) out of the 17 dominant genera in pit mud were successfully enriched, including Petrimonas, Proteiniphilum, Anaerocella, Hydrogenispora, Methanosarcina, Fermentimonas, LNR_A2-18, Sedimentibacter, Lutispora, Syntrophomonas and Aminobacterium. Furthermore, 20 rare genera in the analyzed pit mud samples were also enriched. Aceticlastic Methanosaeta and Methanosarcina were found to be dominant methanogens in the enrichment consortia. Metagenomic sequencing was then applied to the enriched microbial consortia to explore the metabolic potentials of pit mud microbes. Aceticlastic methanogenesis pathway of Methanosaeta was reconstructed. Furthermore, 26 high-quality metagenome-assembled genomes (MAGs) were obtained based on the metagenomic binning analysis. Moreover, nutrients in pit mud were found to be crucial to sustain the methanogenesis of the enriched microbial consortia. These results suggested that the enrichment approach by using oligotrophic culturing can effectively cultivate the pit mud microbiota. Combined with metagenomics, the oligotrophic culturing will be greatly helpful to decipher the community composition and metabolic potentials of pit mud microbiota.
窖泥微生物群在产生中国浓香型白酒风味方面起着关键作用。然而，窖泥微生物群不能在实验室中培养。在这项研究中，使用以乙酸盐为碳源的贫营养培养基来富集窖泥微生物群。应用 16S rRNA 基因扩增子测序来检测富集菌群的微生物动态。同时富集了产甲烷菌和细菌。广古菌门、拟杆菌门和厚壁菌门是前 3 个优势门，成功富集了 31 个属。更具体地说，在窖泥中成功富集了 17 个优势属中的 11 个属（65%），包括 Petrimonas、Proteiniphilum、Anaerocella、Hydrogenispora、Methanosarcina、Fermentimonas、LNR_A2-18、Sedimentibacter、Lutispora、Syntrophomonas 和 Aminobacterium。此外，还富集了分析的窖泥样本中 20 个罕见的属。在富集菌群中发现乙酸营养型 Methanosaeta 和 Methanosarcina 是优势产甲烷菌。然后对富集微生物菌群进行宏基因组测序，以探索窖泥微生物的代谢潜能。重建了 Methanosaeta 的乙酸营养型产甲烷途径。此外，基于宏基因组 binning 分析，获得了 26 个高质量的宏基因组组装基因组（MAGs）。此外，还发现窖泥中的营养物质对维持富集微生物菌群的产甲烷作用至关重要。这些结果表明，使用贫营养培养的富集方法可以有效地培养窖泥微生物群。结合宏基因组学，贫营养培养将极大地有助于破译窖泥微生物群的群落组成和代谢潜能。
