Effect of H₂ on soil bacterial community structure and gene expression

Abstract

Previous studies have showed that H[subscript 2] evolved from HUP- legume nodules is oxidized by rhizospheric microorganisms and alters the soil microbial diversity in rhizosphere. This H[subscript 2] oxidation is linked with the CO[subscript 2] fixation and O[subscript 2] reduction activities. Metatranscriptome analysis in this study revealed that soil bacterial community was changed significantly by H[subscript 2] . Populations of [beta]-proteobacteria and [delta]-proteobacteria were stimulated by H[subscript 2] exposure whereas Actinobacteria was suppressed. Results also showed that genes related with CO[subscript 2] fixation and O[subscript 2] reduction were up-regulated after H[subscript 2] treatment. Several speculated pathways were generated for the H[subscript 2] metabolisms in the soil. The quantification analysis of hydrogenase, the key enzyme in H[subscript 2] oxidation in soil, was carried out using HoxK NiFe hydrogenase small subunit gene via real time PCR. The result showed that the gene copy number had a significant increase after H[subscript 2] treatment.