Effects of dissolved organic matter derived from chicken manure on the biotransformation of roxarsone in soil

Mengtuo Wen; Yaci Liu; Qiulan Zhang; Changli Liu; Yasong Li; Yuqi Yang

doi:10.1016/j.chemosphere.2022.137118

Effects of dissolved organic matter derived from chicken manure on the biotransformation of roxarsone in soil

Chemosphere. 2023 Jan;311(Pt 2):137118. doi: 10.1016/j.chemosphere.2022.137118. Epub 2022 Nov 3.

Authors

Mengtuo Wen¹, Yaci Liu², Qiulan Zhang³, Changli Liu⁴, Yasong Li⁴, Yuqi Yang³

Affiliations

¹ Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang, 050061, PR China; Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen, 361000, PR China; School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China.
² Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang, 050061, PR China; Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen, 361000, PR China. Electronic address: liuyaci@mail.cgs.gov.cn.
³ School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China.
⁴ Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang, 050061, PR China; Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen, 361000, PR China.

PMID: 36336016
DOI: 10.1016/j.chemosphere.2022.137118

Abstract

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, ROX), widely used as a livestock feed additive, is excreted untransformed in large concentrations. Accumulation of this manure in the open environment increases dissolved organic matter (DOM) and ROX in soil within the aeration zone. And microbial action plays a dominant role in the transformation of ROX. However, the specific effect of DOM on the biotransformation of ROX is not known. In this paper, we investigated the transformation rate, metabolite content, and microbial community response of ROX in soils with different DOM concentrations (71.61, 100, 200, 500, and 800 mg L^-1). The transformation of ROX was consistent with first-order transformation kinetics. DOM promoted the transformation of ROX, and with high DOM (DOM ≥200 mg L^-1), ROX was transformed almost completely within two days. In this case, DOM provided nutrients to microorganisms and promoted their growth, accelerating the transformation of ROX. Also, the solubility of ROX was enhanced by DOM to increase its bioavailability. The microbial diversity was negatively correlated with DOM concentration and ROX transformation time; during the transformation of ROX, Bacillus, Arthrobacter, Enterococcus, Acinetobacter, and Pseudomonas became dominant in the soil with anomalously high levels of DOM. This study demonstrates the transformation process of ROX under actual environmental conditions where organic matter coexists with ROX, and this understanding is important for the prevention and control of arsenic pollution in soil within the aeration zone with anomalously high levels of DOM.

Keywords: Arsenic contamination; Biotransformation; Dissolved organic matter; Microbial communities; Roxarsone; Soil.