Comparisons of four As(V)-respiring bacteria from contaminated aquifers: activities to respire soluble As(V) and to reductively mobilize solid As(V)

Contradictory Impacts of Nitrate on the Dissimilatory Arsenate-Respiring Prokaryotes-Induced Reductive Mobilization of Arsenic from Contaminated Sediments: Mechanism Insight from Metagenomic and Functional Analyses

“…19−22 DARPs are capable of anaerobically reducing As(V) into As(III) utilizing short-chain fatty acids, including formate, acetate, lactate, glycerin, pyruvate, and syringate, as an electron donor. 18,23,24 The As(V)-respiring activities of DARPs are attributed to the fact that there is an As(V)-respiring reductase (Arr) in the DARP cells. 55 Arr contains A and B subunits.…”

“…19,21,22 However, their activity to reduce solid As(V) is much lower than that of DARPs to reduce soluble As(V). 23 Even so, DARPs are still considered to be a key driver for the reductive mobilization of solid As. DARPs widely inhabit in a diverse As-contaminated environment, including various soils, water, sediments, and mining tailings.…”

“…Although other abiotic factors also participate in weathering, reduction, and mobilization of arsenic; however, undoubtedly, the microbial community in the environment is the major impetus of the arsenic biogeochemical cycle. – There are at least three large classes of As-metabolizing microorganisms: As­(III)-oxidizing prokaryotes (AOPs), dissimilatory As­(V)-respiring prokaryotes (DARPs), and As-methylating prokaryotes (AMPs). – Among them, DARPs are attracting high attention because they are considered to be a key culprit causing high-arsenic groundwater. – DARPs are capable of anaerobically reducing As­(V) into As­(III) utilizing short-chain fatty acids, including formate, acetate, lactate, glycerin, pyruvate, and syringate, as an electron donor. ,, The As­(V)-respiring activities of DARPs are attributed to the fact that there is an As­(V)-respiring reductase (Arr) in the DARP cells . Arr contains A and B subunits .…”

“…ArrA is a catalytic subunit, and its gene arrA was utilized as a genetic marker to identify DARPs in the environment . Some investigations demonstrated that DARPs are able to directly reduce As­(V) in solid phase. ,, However, their activity to reduce solid As­(V) is much lower than that of DARPs to reduce soluble As­(V) . Even so, DARPs are still considered to be a key driver for the reductive mobilization of solid As.…”

A Novel Mn- and Fe-Oxides-Reducing Bacterium with High Activity to Drive Mobilization and Release of Arsenic from Soils

“…Microbes can use arsenic as an electron donor or acceptor for their metabolic activities, depending on the environmental conditions and the availability of other electron donors or acceptors [12,13]. One of the main microbial processes that promote arsenic mobilization is the dissimilatory reduction of arsenate (As(V)) to arsenite (As(III)), which is more toxic and mobile than As(V) [14][15][16]. This process can be coupled with the oxidation of organic matter or methane as electron donors [17,18].…”