Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Poland.
AGH University of Science and Technology, Faculty of Geology, Geophysics and Environmental Protection, Department of Mineralogy, Petrography and Geochemistry, Krakow, Poland.
Ecotoxicol Environ Saf. 2021 Apr 15;213:112054. doi: 10.1016/j.ecoenv.2021.112054. Epub 2021 Feb 15.
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 AsS. 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.
废菌糠（SMC）是一种富含木质纤维素的废料，常用于重金属污染环境的被动处理。在这项研究中，我们研究了 SMC 对无机砷的生物修复潜力，考察了 SMC 进行的单独非生物和生物转化。我们证明了，SMC 中的关键细菌生理群（反硝化菌、纤维素分解菌、硫酸盐还原菌和异养菌）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在呼吸代谢中氧化 As(III)和还原 As(V)，尽管 SMC 中并不含有任何 As。我们表明，砷酸盐和硫酸盐还原菌之间的合作导致了 AsS 的沉淀。我们还发现了有机酸在砷络合中可能发挥重要作用的证据，并在 SMC 中证明了砷结合蛋白的存在。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 SMC 在吸附实验中表现出对 As(V)（高达 25%）和 As(III)（高达 16%）的高吸附效率以及优异的缓冲性能的原因。
