fmicb-12-634025 March 13, 2021 Time: 16:38 # 1 ORIGINAL RESEARCH published: 19 March 2021 doi: 10.3389/fmicb.2021.634025 Adaptation of Microbial Communities to Environmental Arsenic and Selection of Arsenite-Oxidizing Bacteria From Contaminated Groundwaters Sarah Zecchin1, Simona Crognale2, Patrizia Zaccheo3, Stefano Fazi2, Stefano Amalfitano2, Barbara Casentini2, Matteo Callegari1, Raffaella Zanchi1, Gian Attilio Sacchi3, Simona Rossetti2 and Lucia Cavalca1* 1 Dipartimento di Scienze per gli Alimenti, la Nutrizione e l’Ambiente (DeFENS), Università degli Studi di Milano, Milano, Italy, 2 Water Research Institute, National Research Council of Italy (IRSA-CNR), Rome, Italy, 3 Dipartimento di Scienze Agrarie e Ambientali—Produzione, Territorio, Agroenergia (DiSAA), Università degli Studi di Milano, Milano, Italy Arsenic mobilization in groundwater systems is driven by a variety of functionally diverse Edited by: Gonzalo Durante-Rodriguez, microorganisms and complex interconnections between different physicochemical Spanish National Research Council, factors. In order to unravel this great ecosystem complexity, groundwaters with Spain varying background concentrations and speciation of arsenic were considered in Reviewed by: Pinaki Sar, the Po Plain (Northern Italy), one of the most populated areas in Europe affected Indian Institute of Technology by metalloid contamination. High-throughput Illumina 16S rRNA gene sequencing, Kharagpur, India Jagat Rathod, CARD-FISH and enrichment of arsenic-transforming consortia showed that among the National Cheng Kung University, analyzed groundwaters, diverse microbial communities were present, both in terms of Taiwan diversity and functionality. Oxidized inorganic arsenic [arsenite, As(III)] was the main *Correspondence: driver that shaped each community. Several uncharacterized members of the genus Lucia Cavalca
[email protected] Pseudomonas, putatively involved in metalloid transformation, were revealed in situ in the most contaminated samples.