Pit mud is an important habitat for anaerobic microbes that are involved in the production of aromas and flavors for strong-flavor Baijiu. However, most of the anaerobes have not been cultured under artificial culture conditions, which severely hinders the understanding of the functions of anaerobes in pit mud. To explore the types and dynamics of the enriched microbiota, CGM, NBM, and MCI culture media with different nutrients were used. Typical pit muds from a Chinese strong-flavor type liquor distillery were used as inocula. Combined with amplicon sequencing technique, the results showed that oligotrophic MCI medium was the most effective medium to enrich the dominant microbes in pit muds, including Euyarchaeota, Bacteroidetes and Firmicutes at the same time. The oligotrophic culturing based on MCI medium not only enriched the high- and low-abundance anaerobes in pit muds such as Prevotellaceae, Rikenellaceae, Dysgonomonadaceae, Heliobacteriaceae, Ruminococcaceae and Methanosarcinaceae, but also effectively enriched rare anaerobes such as Methanosaetaceae, Peptostreptococcacea, Enterobacteriaceae, Oligosphaeraceae, Cloacimonadaceae, Fibrobacteraceae, and Pedosphaeraceae. More detailed microbial structures and species composition of the enriched microbiota were further revealed by metagenomics sequencing. In this study, combined with high-throughput sequencing approaches, oligotrophic culturing technique shows high values on illuminating the classification and genomic structures as well as the metabolic potentials of pit mud microbiota.
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