Production of arsine and methylarsines in soil and in culture

Abstract

Arsenate, arsenite, monomethylarsonate, and dimethylarsinate were added to three different soils, and the evolution of gaseous arsenical products was determined over 3 weeks. Arsine was produced in all three soils from all substrates, whereas methylarsine and dimethylarsine were produced only from methylarsonate and dimethylarsinate, respectively. At least three times more arsine than dimethylarsine was produced in soil incubated with dimethylarsinate. Resting cell suspensions of Pseudomonas and Alcaligenes produced arsine as the sole product when incubated anaerobically in the presence of arsenate or arsenite. In all instances, no trimethylarsine was observed, nor could any evidence be shown for the methylation of any arsenical substrate in soil or in culture. It was concluded that reduction to arsine, not methylation to trimethylarsine, was the primary mechanism for gaseous loss of arsenicals from soil.

Growth of Strain SES-3 with Arsenate and Other Diverse Electron Acceptors

“…Strains of Pseudomonas and Alcaligenes spp. reduced As(V) and As(III) to As(ϪIII) but did not employ them as respiratory electron acceptors for growth (3).…”

Leaching of wood preservative components and their mobility in the environment : summary of pertinent literature

“…Although the significance of these microbial activities in preservative leaching is unknown, evidence shows that microorganisms affect the mobility and fate of arsenic when it enters the environment. Many common soil fungi and bacteria are capable of reducing arsenate to arsenite (Bautista and Alexander 1972;Osborne and Erlich 1976) or methylate oxyanions (Braman 1975;Cheng and Focht 1979;Cox 1974;Cullen and others 1984;O'Neill 1990;Sandberg and Allen 1975;Stranks 1976). Researchers have postulated that biomethylation plays a vital role in the global arsenic cycle by volatilizing and redistributing the element (Sandberg and Allen 1975;Wood 1974).…”

“…The soluble methylated forms then move up to the water surface where they can react with oxygen to form oxyanions that are again precipitated by reactions with inorganic constituents (Ferguson and Gavis 1972;Wood 1974). The biomethylation reactions that occur are influenced by not only the microorganisms present, but also the species of arsenic involved (Cheng and Focht;O'Neill 1990). Some organisms appear able to fully methylate arsenic compounds over a wide range of pH values, and others can methylate only certain species and to a lesser degree (O'Neill 1990).…”

Arsenic Concentration in the Surface Water of a Former Mining Area: The La Junta Creek, Baja California Sur, Mexico

“…In the surface water, under the oxidizing environmental conditions, the pentavalent species of arsenic are predominant; only one sample showed reducing environmental conditions with predominance of the (As 3+ ) species. The trivalent compounds of arsenic are generally more toxic than pentavalent compounds [ 53 , 54 , 55 , 56 ]). Although the observed arsenic concentrations in the surface water are lower than the concentrations of arsenic, reported for the groundwater of the same area [ 26 ], a negative impact may result because even low levels of As may be carcinogenic.…”