Investigation of Arsenotrophic Microbiome in Arsenic‐Affected Bangladesh Groundwater

Abstract

Arsenotrophic bacteria contribute to the nutrient cycling in arsenic (As) affected groundwater. This study employed a culture-independent and -dependent investigation of arsenotrophic microbiomes in As affected groundwater samples collected from Madhabpur, Sonatengra, and Union Porishod in Singair Upazila, Manikganj, Bangladesh. Total As contents, detected by Atomic Absorption Spectrophotometry (AAS) of the samples, were 47 µg/L (Madhabpur, SNGW-1), 53 µg/L (Sonatengra, SNGW-2), and 12 µg/L (Union porishod, SNGW-3), whereas the control well (SNGW-4; depths >150 m) showed As content of 6 µg/L. Denaturing Gradient Gel Electrophoresis (DGGE) analysis of the amplified 16S rRNA gene from As-affected groundwater samples revealed the dominance of aerobic bacteria Pseudomonas within heterogeneous bacterial populations. DGGE of heterotrophic enrichments supplemented with arsenite [As (III)] for 4 weeks showed the dominance of Chryseobacterium, Flavobacterium, and Aquabacterium, whereas the dominant genera in that of autotrophic enrichments were Aeromonas, Acinetobacter, and Pseudomonas. Cultured bacteria retrieved from both autotrophic and heterotrophic enrichments were distinguished into nine genotypes belonging to Chryseobacterium, Acinetobacter, Escherichia, Pseudomonas, Stenotrophomonas, Janibacter, Staphylococcus, and Bacillus. They exhibited varying range of As(III) tolerance from 4 to 27 mM. As(III) transformation potential was confirmed within the isolates with oxidation rate as high as 0.143 mM/h for Pseudomonas sp. Sn 28. The arsenotrophic microbiome specifies their potential role in groundwater As-cycling and their genetic information provide the scientific basis for As-bioremediation.

Exploring Biodiversity and Arsenic Metabolism of Microbiota Inhabiting Arsenic-Rich Groundwaters in Northern Italy

“…For other species retrieved in autotrophic consortia (i.e., Sphingopyxis chilensis, Luteimonas aestuarii , and Lysobacter capsici ), the oxidative activity has never been demonstrated, although in GenBank several As gene sequences are deposited from the genome of related species, including genes for As(III) oxidation. In the heterotrophic As(III)-oxidizing cultures (Supplementary Table 6), several As(III) oxidizers were found, including a close relative of Delftia sp., which was shown to be a facultative chemolithoautotrophic As(III) oxidizer (Sultana et al, 2017). In As(V) reducing enrichments most of the strains already retrieved in As(III) oxidizing cultures were detected, with the exception of Microbacterium hydrocarbonoxydans and Rhodococcus ruber strains (Supplementary Table 7).…”

“…Previous studies focused on the microbiological characterization of As-rich groundwaters in South and South East Asia, including Bangladesh (Hassan et al, 2016; Sultana et al, 2017), China (Guo et al, 2015; Li P. et al, 2015; Wang et al, 2016), West Bengal (Osborne et al, 2015) and Taiwan (Das et al, 2016). Here, As pollution is more severe in shallow aquifers (generally < 50 m below surface) formed by Holocene sediments (Ravenscroft et al, 2009; Fendorf et al, 2010; Zheng et al, 2019).…”

Exposure to Arsenic Alters the Microbiome of Larval Zebrafish

“…Mounting concern over arsenic contamination in drinking water has led to a better understanding of both arsenic's negative outcomes on human health (Smith et al, 2000 ) and its influence on microbial communities in the environment (Cai et al, 2009 ; Sarkar et al, 2012 ; Escudero et al, 2013 ; Bhadury, 2014 ; Farias et al, 2015 ; Paul et al, 2015 ; Sultana et al, 2017 ). In this study, we investigated whether environmental concentrations of arsenic can perturb microbiota in developing zebrafish larvae.…”

Next-generation sequencing showing potential leachate influence on bacterial communities around a landfill in China

“…The high concentration of As and Hg in RL and FL2 could have inhibited the growth of other phyla, whereas Pseudomonas spp. have recently been identified as key members of arsenotrophic consortia in contaminated groundwater environments in Bangladesh (Sultana et al, 2017). The low diversity in leachate samples, compared with samples taken from within the landfill (e.g., (Wang et al, 2017) may also be due to the concentration of landfill microbiota within surface-attached biofilms rather than in mobile planktonic forms (Costerton and Wilson, 2004).…”