Biological effect of phosphate on the dissimilatory arsenate-respiring bacteria-catalyzed reductive mobilization of arsenic from contaminated soils

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

“…The expression of arrAB genes was effectively activated and induced by both As­(III) and As­(V). , Numerous studies have highlighted the significant influence of environmental factors on the expression of the microbial arrAB genes. For example, humic substances and biochar, serving as electron shuttles, have been demonstrated to markedly enhance the transcription of the microbial arrA gene. ,, Phosphates can facilitate arrA gene expression by increasing substrate As­(V) availability and inhibiting the entry of As­(V) into bacteria, thereby reducing the usage of the ArsC detoxification system that is high-energy-consuming . Sulfate can promote bacterial metabolism, leading to increased arrA gene expression per DARP cell .…”

“…31,63,64 Phosphates can facilitate arrA gene expression by increasing substrate As(V) availability and inhibiting the entry of As(V) into bacteria, thereby reducing the usage of the ArsC detoxification system that is high-energy-consuming. 32 Sulfate can promote bacterial metabolism, leading to increased arrA gene expression per DARP cell. 29 Furthermore, manganese enhances bacterial resistance to arsenic and promotes bacterial growth, thereby further increasing arrA gene expression.…”

“…The bacterial enrichment approach was utilized to isolate representative cultivable DARP strains from the As-contaminated sediments. 32 Approximately 5 g of solids were ground and placed into an anaerobic bottle with 20 mL of O 2 -free MMM, supplemented with 1 mM As(V) and 5 mM pyruvate. The bottles were cultivated at 30 °C under anaerobic conditions until all As(V) were converted into As(III).…”

“…Recent investigations suggest that environmental factors, such as sulfate, manganese chloride, humic acid, and phosphate, significantly affect the DARPs-mediated reductive mobilization of As in contaminated soils and sediments through interfering the bacterial activities or growth. – Additionally, nitrate stands as another commonly seen environmental contaminant. Most nitrate contaminants are derived from agricultural fertilizers, microbial degradation of plant residues and animal manure, industrial wastewater, as well as weathering and transformation of N-bearing ore minerals. , In uncultivated soils, nitrate contents vary between 5 and 10 mg/kg.…”

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

“…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]. This process can increase the arsenic concentration in groundwater by several orders of magnitude [19,20].…”