Microbiomes in agricultural and mining soils contaminated with arsenic in Guanajuato, Mexico

In this report, physical and chemical properties, and total arsenic (As) concentrations were analyzed in agricultural (MASE) and mining soils (SMI) in the State of Guanajuato, Mexico. Additionally, a metagenomic analysis of both types of soils was the bases for the identification and selection of bacteria and fungi resistant to As. The SMI soil showed higher concentration of As (39 mg kg(-1)) as compared to MASE soil (15 mg kg(-1)). The metagenome showed a total of 175,240 reads from both soils. MASE soil showed higher diversity of bacteria, while the SMI soil showed higher diversity of fungi. 16S rRNA analysis showed that the phylum Proteobacteria showed the highest proportion (39.6% in MASE and 36.4% in SMI) and Acidobacteria was the second most representative (24.2% in SMI and 11.6% in MASE). 18S rRNA analysis, showed that the phylum Glomeromycota was found only in the SMI soils (11.6%), while Ascomycota was the most abundant, followed by Basidiomycota, and Zygomycota, in both soils. GeneraBacillusandPenicilliumwere able to grow in As concentrations as high as 5 and 10 mM, reduced As (V) to As (III), and removed As at 9.8% and 12.1% rates, respectively. WhenaoxB,arsB, ACR3(1), ACR3(2,)andarrAgenes were explored, only thearsBgene was identified inBacillussp.,B. simplex, andB. megaterium. In general, SMI soils showed more microorganisms resistant to As than MASE soils. Bacteria and fungi selected in this work may show potential to be used as bioremediation agents in As contaminated soils.

Automated summary

This report analyzed physical and chemical properties, as well as total arsenic concentrations in agricultural and mining soils in Guanajuato, Mexico. Metagenomic analysis identified bacteria and fungi resistant to arsenic, with the mining soil showing higher arsenic concentration. The study found that microorganisms in mining soils exhibited greater resistance to arsenic compared to agricultural soils.