Microbial Community Succession is Associated With Corn Straw Degradation in Microbial Consortium M44 During Subculture

Abstract

To systematically analyze the succession of functional microbiota that plays an important role during culture of microbial consortia M44 and its relationship with straw degradation characteristics, we determined the straw degradation ratio and activities of cellulose, hemicellulose, lignin enzyme, and VFA content of M44 in different culture periods. We also used 16S rRNA gene sequencing to analyze the change in microbial community structure in M44 and explore the differences in microbial composition in the original sample. The results showed that at 15 ℃ for 21 days, the straw degradation rate, endoglucanase activity, and filter paper enzyme activity of M44 generally decreased with increasing culture age, reaching their highest values at F1. The activities of xylanase, laccase, and lignin peroxidase, as well as VFA content, were the highest at F5, showing a single-peak curve change with first an increase and then decrease. At the phylum level, Proteobacteria, Bacteroidetes, and Firmicutes were dominant in the original samples and in different culture stages. At the genus level, Devosia and Bacillus were dominant in the original sample. During subculture, the dominant bacteria in the first generation (F1) were Pseudomonas, Flavobacterium, Brevundimonas, Achromobacter, Chryseobacterium, and Devosia. The dominant genera in the last generation (F11) were Trichococcus, Acinetobacter, Dyssgonomonas, and Rhizobium. In conclusion, we identified changes in microbial community structure occurring in M44 during subculture, as well as similarities and differences in microbial communities from the original sample.