鲤 Cyprinus carpio 生物扰动对养殖池塘底质甲烷生成的影响及其微生物学机制

To study the effect of bioturbation by Cyprinus carpio on the formation of methane in pond sediment, we measured the methanogenic potential in the sediment, the composition of the methanogens microbial community, and the interaction between methanogen groups in laboratory simulation experiment. Results show that, compared with the control group, the methanogenic potential of the disturbed group was significantly reduced. The gene abundance of total bacteria and total archaea in the sediment increased significantly while the abundance of mcrA decreased significantly due to the bioturbation. The dominant groups of methanogens indentified were Methanobacterium, Methanothrix, Methanoregula, and Methanocella. The methanogens in the disturbed group showed high α-diversity. Bioturbation was not conducive to the interaction among methanogens in sediment, and the symbiotic network relationship were less complicated. The average degree and number of links of symbiotic network were significantly reduced, while the modularity was higher. The among-species symbiotic network was negatively correlated with competition. Pearson correlation analysis indicated that the bottom redox potential was a key environmental factor affecting the abundance of mcrA gene and the structure of methanogenic bacteria. The bioturbation effect of C. carpio may reduce the potential for methane production in the sediment by increasing the redox potential of the sediment, thereby reducing the abundance of methanogenic functional bacteria and interspecies interactions.