Diversity of Fe-hydrogenase microbe in Guizhou red paddy soil during flooding incubation

Abstract:

Abstract:［Objective］ The diversity of Fe-hydrogenase based on Fe-hydrogenase gene of Clostridium was studied for exploring the biochemical mechanism of soil microbial hydrogen production and revealing the Fe-hydrogenase microbial community structure changes during the paddy soil flooding incubation ［Methods］ We used denatured gradient gel electrophoresis and real-time quantitative PCR to achieve the goal． ［Results］ The band number of Fe-hydrogenase denatured gradient gel electrophoresis fingerprints indicated Fe-hydrogenase microbes structure varied significantly during the completely flooding incubation． The Principal Component Analysis (PCA) showed the highly similar communities of Fe-hydrogenase microbial was divided into three groups: 1 d and 20 d，the 5 d，30 d and 40 d．With the growth of the flooding incubation time Fe-hydrogenase microbial community structure became relatively stable and convergence． α diversity index analysis found that the richness index (R)，Shannon-Weaver index (H')，Simpson index (DS) numerical values of 1 d and 10 d were lower compared with other points，indicated the two time points of low Fe-hydrogenase diversity，simple Fe-hydrogenase microbial community structure and successive variation of community structure during the whole flooding incubation． After sequencing 15 Fe-hydrogenase preponderant bands (labeled by G1－G15)，the phylogenetic tree of Fe-hydrogenase showed that the preponderant bands all had high similarity with the Clostridium Fehydrogenase in earlier flooding incubation stage and non-Clostridium Fe-hydrogenase in the later stage．Real-time quantitative PCR results demonstrated that the Fe-hydrogenase gene copy number was 106 level．［Conclusion］ In the research we found 4 kinds of Clostridium Fe-hydrogenases and three kinds of non-lostridium Fe-hydrogenases，the corresponding Fe-hydrogenase microbial community structure had successively significant variation in the early incubation stage and tend to be relatively stable and convergence in the late stage．