Arsenicicoccus bolidensis a novel arsenic reducing actinomycete in contaminated sediments near the Adak mine (northern Sweden): Impact on water chemistry

Weathering of mine tailings in Adak results in high As concentrations in surface and ground water, sediments, and soil. In spite of the oxic conditions, As-rich surface and ground water samples indicate As(III) species predominantly (up to 83%). Several microorganisms were isolated from the enrichment cultures that were involved in As cycling. Amongst them was Arsenicicoccus bolidensis—a novel gram-positive, facultatively anaerobic, coccus-shaped actinomycete, which actively reduced As(V) to As(III) in aqueous media. A. bolidensis reduced 0.06–0.20 mM day−1 As(V). As(V) reduction displays a direct correlation between the initial As(V) concentration, growth rate, and biomass yield.