Spent mushroom compost (SMC) is a lignocellulose-rich waste material commonly used in the passive treatment of heavy metal-contaminated environments. In this study, we investigated the bioremediation potential of SMC against an inorganic form of arsenic, examining the individual abiotic and biotic transformations carried out by SMC. We demonstrated, that key SMC physiological groups of bacteria (denitrifying, cellulolytic, sulfate-reducing, and heterotrophic) are resistant to arsenites and arsenates, while the microbial community in SMC is also able to oxidize As(III) and reduce As(V) in respiratory metabolisms, although the SMC did not contain any As. We showed, that cooperation between arsenate and sulfate-reducing bacteria led to the precipitation of As_xS_y. We also found evidence of the significant role organic acids may play in arsenic complexation, and we demonstrated the occurrence of As-binding proteins in the SMC. Furthermore, we confirmed, that biofilm produced by the microbial community in SMC was able to trap As(V) ions. We postulated, that the above-mentioned transformations are responsible for the sorption efficiency of As(V) (up to 25%) and As(III) (up to 16%), as well as the excellent buffering properties of SMC observed in the sorption experiments.

废蘑菇堆肥（SMC）是一种富含木质纤维素的废料，通常用于被动处理重金属污染的环境。在这项研究中，我们调查了SMC对无机形式的砷的生物修复潜力，并研究了SMC进行的单个非生物和生物转化。我们证明，细菌的关键SMC生理基团（硝化，纤维素分解，硫酸盐还原和异养）对亚砷酸盐和砷酸盐具有抗性，而SMC中的微生物群落也能够氧化As（III）和还原As（V）在呼吸代谢中，尽管SMC不包含任何As。我们表明，砷酸盐和硫酸盐还原菌之间的合作导致As _x S _y的沉淀。我们还发现有机酸可能在砷络合物中发挥重要作用的证据，并且我们证明了SMC中As结合蛋白的出现。此外，我们证实，SMC中微生物群落产生的生物膜能够捕获As（V）离子。我们推测，上述转化是As（V）（高达25％）和As（III）（高达16％）的吸附效率以及在SMC中观察到的SMC优异的缓冲性能的原因。吸附实验。