Microbial transformation of arsenic in Bengal floodplain

However, to date there is limited data on how geomorphology, land use and soil microbes drive bioavailability of arsenic in the paddy soil in Bangladesh. In the present study, 16S rRNA amplicon sequencing and metagenomics (Illumina), alongside chemical analysis in paddy and nonpaddy soils, from Holocene and Pleistocene regions, of Bangladesh to investigate microbial composition and functional diversity of arsenic metabolism genes and how this may be related to differences in arsenic dynamics within these soils.

Compared to Pleistocene soils, the Holocene soils had higher concentrations of arsenic, other elements and pore water arsenic species, the latter dominated by iAs. Further to that, paddy soils were shown to be elevated in arsenic and soil solution arsenic species compared to nonpaddy soils. Based on 16S rRNA amplicon sequencing and metagenomics the dominant bacterial phyla common to all soils were Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi and Firmicutes but the overall diversity of bacteria was shown to be significantly higher in Holocene compared to Pleistocene soil.