Influence of organic matters on AsIII oxidation by the microflora of polluted soils

• Published in: Environmental geochemistry and health Vol. 38; no. 3; pp. 911 - 925
• Main Authors: Lescure, T., Moreau, J., Charles, C., Ben Ali Saanda, T., Thouin, H., Pillas, N., Bauda, P., Lamy, I., Battaglia-Brunet, F.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2016; Springer Nature B.V; Springer Verlag (Germany)
• Subjects: Aerobic conditions; Arsenic; Arsenic - chemistry; Arsenic - metabolism; Continental interfaces, environment; Culture Media; Earth and Environmental Science; Environment; Environmental Chemistry; Environmental Health; France; Geochemistry; Microbiological culture; Microbiota - physiology; Microorganisms; Nutrient availability; Organic carbon; Organic Chemicals - chemistry; Organic matter; Original Paper; Oxidation; Oxidation-Reduction; Pollution; Public Health; Sciences of the Universe; Soil - chemistry; Soil Microbiology; Soil nutrients; Soil organic matter; Soil Pollutants - chemistry; Soil pollution; Soil Science & Conservation; Soil surfaces; Soils; Speciation; Substrates; Terrestrial Pollution; Yeasts; Polluted soils; Organic matter; Microorganisms; AsIII oxidation; Arsenic
• ISSN: 0269-4042; 1573-2983
• DOI: 10.1007/s10653-015-9771-3

The global AsIII-oxidizing activity of microorganisms in eight surface soils from polluted sites was quantified with and without addition of organic substrates. The organic substances provided differed by their nature: either yeast extract, commonly used in microbiological culture media, or a synthetic mixture of defined organic matters (SMOM) presenting some common features with natural soil organic matter. Correlations were sought between soil characteristics and both the AsIII-oxidizing rate constants and their evolution in accordance with inputs of organic substrates. In the absence of added substrate, the global AsIII oxidation rate constant correlated positively with the concentration of intrinsic organic matter in the soil, suggesting that AsIII-oxidizing activity was limited by organic substrate availability in nutrient-poor soils. This limitation was, however, removed by 0.08 g/L of added organic carbon. In most conditions, the AsIII oxidation rate constant decreased as organic carbon input increased from 0.08 to 0.4 g/L. Incubations of polluted soils in aerobic conditions, amended or not with SMOM, resulted in short-term As mobilization in the presence of SMOM and active microorganisms. In contrast, microbial AsIII oxidation seemed to stabilize As when no organic substrate was added. Results suggest that microbial speciation of arsenic driven by nature and concentration of organic matter exerts a major influence on the fate of this toxic element in surface soils.