Arsenic biomineralization and selenium nanoparticles biosynthesis by Halomonas boliviensis strain H-10 isolated from the high-altitude Salar de Huasco salt flat (Chile)

Abstract

High-altitude Andean wetlands of the Atacama Desert (Chile), including the Salar de Huasco salt flat, are unusual environments characterized by a great variability of physical-chemical conditions, often combined with a high concentration of heavy metals, including arsenic (As) and semimetals, such as selenium (Se). Microorganisms present in these environments evolved adaptative strategies to cope with environmental stresses, with biotechnological potentials. The present work investigated the natural bacterial community composition in sediments collected from the Salar de Huasco salt flat, by high-throughput Illumina sequencing, and to isolate bacterial strains able to remove As and biosynthesize Se nanoparticles (SeNPs). Dominant taxonomic groups (abundance ≥1%) were affiliated to Proteobacteria (mainly consisting in Delta- and Alfa- Gamma-proteobacteria) Bacteriodetes, Firmicutes, Acidobacteria, Spirochaetes, Deinococcus-Thermus, Gemmatimonadetes and Verrucomicrobia. Halomonas boliviensis strain H-10 was able to both biomineralize As and biosynthesise SeNPs; therefore, the characteristics of H. boliviensis strain H-10 could be used for biotechnological purposes, including As bioremediation from water and bioproduction of SeNPs.