Abundance and diversity of carbon monoxide dehydrogenase genes from BMS clade bacteria in different vegetated soils

- The abundance and diversity of BMS-type coxL genes were high in different vegetated soils.
- The abundance of BMS-type coxL genes varied with the type of vegetated soils.
- The abundance of BMS-type coxL genes was significantly affected by total P and Olsen -P concentrations in vegetated soils.

Carbon monoxide (CO)-oxidizing bacteria are active consumers of atmospheric CO, undergoing a CO oxidation process that is catalyzed by carbon monoxide dehydrogenase (CODH). Little is known about the phylogeny of a group of bacterial CO-oxidizers known as the BMS clade, which possess putative CODH genes, or their abundances in soils. In this study coxL genes indicative of bacteria belonging to the BMS clade were amplified from DNA directly extracted from four vegetated soils: paddy rice (PR) soil, maize cropland (ML) soil, tea plantation (TP) soil, and natural forest (NF) soil. Quantitative PCR (qPCR) analysis showed that BMS coxL gene copy numbers ranged from 1.47 × 107 to 7.40 × 108 copies g−1 dry soil and differed significantly among PR, ML, TP, and NF soils (P < 0.05). CoxL gene abundance appeared to be linked to total P and Olsen P concentrations, as revealed by correlation analysis (P < 0.05). Phylogenetic analysis of BMS coxL sequences indicated a diverse clade of BMS CO oxidizers closely related to Bradyrhizobium sp. ARR65, Rhizobiales GAS188, Paraburkholderia phytofirmans, and Tistlia consotensis. However, the community compositions of BMS coxL-containing bacteria differed among soils. Collectively, these results indicate a high abundance and diversity of BMS clade CO oxidizers in a wide variety of vegetated soils.