复配菌群降解煤产甲烷的宏基因组与宏转录组分析OA北大核心CSTPCD

[Objective]Aromatic compound metabolism is considered a limiting factor for the generation of biogenic coalbed methane.To increase biomethane production from coal,the compounded microflora(CM)was obtained by compounding raw inoculum(RI)with ability of producing methane by degrading coal and phenanthrene-degrading functional microflora enriched from produced water.[Method]A combined metagenome and metatranscriptome approach was used to analyze the differences in the community structure and metabolic pathways of CM and RI.[Result]The methane yield of CM increased significantly by 114.55%.Compounding significantly increased the proportion of aromatics-degrading bacteria,such as Pseudomonas,accounting for 63.49%,and also increased the metabolic activity of the dominant bacteria as well as the synthesis and expression of the key enzymes in the metabolic pathway of aromatic compounds.Gene abundance of the aromatics-degrading pathway in CM was 1.65 times higher than that of RI,and the gene expression abundance was 6.34 times higher than that of RI(P<0.05).The gene abundance and expression abundance of EC:1.13.11.2 were 2.24 and 62 times higher than those of RI,respectively.The increased expression abundance of these enzymes prompted the transformation of aromatic compounds to pyruvate.Compounding also enhanced the gene expression during the process of pyruvate metabolism to acetyl-CoA.The expression abundance of EC:1.2.4.1 reached 14.70-fold of the RI in CM.The gene expression abundance of the respective methanogenic pathways in CM was 2.66 to 7.10-fold of the RI.[Conclusion]The compounding enriched the aromatics-degrading bacteria and significantly increased gene abundance,especially gene expression abundance,in the whole metabolic pathway of degrading aromatics to methane generation,resulting in the increased methane production.