Response of soil microbial communities to roxarsone pollution along a concentration gradient

Abstract

The extensive use of roxarsone (3-nitro-4-hydroxyphenylarsonic acid) as a feed additive in the broiler poultry industry can lead to environmental arsenic contamination. This study was conducted to reveal the response of soil microbial communities to roxarsone pollution along a concentration gradient. To explore the degradation process and degradation kinetics of roxarsone concentration gradients in soil, the concentration shift of roxarsone at initial concentrations of 0, 50, 100, and 200 mg/kg, as well as that of the arsenic derivatives, was detected. The soil microbial community composition and structure accompanying roxarsone degradation were investigated by high-throughput sequencing. The results showed that roxarsone degradation was inhibited by a biological inhibitor, confirming that soil microbes were absolutely essential to its degradation. Moreover, soil microbes had considerable potential to degrade roxarsone, as a high initial concentration of roxarsone resulted in a substantially increased degradation rate. The concentrations of the degradation products HAPA (3-amino-4-hydroxyphenylarsonic acid), AS(III), and AS(V) in soils were significantly positively correlated. The soil microbial community composition and structure changed significantly across the roxarsone contamination gradient, and the addition of roxarsone decreased the microbial diversity. Some bacteria tended to be inhibited by roxarsone, while Bacillus, Paenibacillus, Arthrobacter, Lysobacter, and Alkaliphilus played important roles in roxarsone degradation. Moreover, HAPA, AS(III), and AS(V) were significantly positively correlated with Symbiobacterium, which dominated soils containing roxarsone, and their abundance increased with increasing initial roxarsone concentration. Accordingly, Symbiobacterium could serve as indicator of arsenic derivatives released by roxarsone as well as the initial roxarsone concentration. This is the first investigation of microbes closely related to roxarsone degradation.

Diagnosing bioremediation of crude oil-contaminated soil and related geochemical processes at the field scale through microbial community and functional genes

“…Metagenomic sequencing was conducted on the MiSeq sequencing platform at Sangon Biotech Co., Ltd. (Shanghai, China) (Hatta et al 2016). The sequence reads were trimmed, optimized, subsampled, aligned, and clustered into operational taxonomic units (OTUs) (Liu et al 2017). The representative sequences were annotated with the RDPclassifier 2.2 (QIIME) (Lan et al 2012).…”

Soil Pollution Characteristics and Microbial Responses in a Vertical Profile with Long-Term Tannery Sludge Contamination in Hebei, China

“…High-throughput sequencing was conducted for analyzing the microbial community compositions and their functions in the soil samples by Shanghai Personal Biotechnology Co., Ltd. (Shanghai, China). DNA extraction, PCR amplification, purification, pooling, and sequencing of a region of the 16S rRNA gene were performed using standard procedures [18]. Total bacterial genomic DNA samples were extracted using the Fast DNA SPIN extraction kits (MP Biomedicals, Santa Ana, CA, USA).…”

“…The UPGMA employed a sequential clustering algorithm to identify the local topological relationships in order of similarity, and the phylogenetic tree was built in a stepwise manner [22]. The responses of soil microorganisms to the contaminant factors were evaluated using the spearman rank correlation, and the significant differences of statistical tests were estimated at a significance level of p < 0.05 [18].…”

Identification of an anaerobic bacterial consortium that degrades roxarsone

“…Approximately 80% of the additive is discharged to the environment in poultry urine and excrement and degraded into more toxic compounds such as As(V) and As(III). Various arsenic speciation forms can be detected in animal manure or ROX amended soil, such as As(V), As(III), HAPA (3‐amino‐4‐hydroxy benzyl arsonic acid), MMA (methyl arsonic acid), DMA (dimethyl arsonic acid), and other arsenic species (Cortinas et al, ; Garbarino, Bednar, Rutherford, Beyer, & Wershaw, ; Ji, Shi, Kong, & Lu, ; Liu, Zhang, Li, Wen, & Fei, ; Yang et al, ; Yao et al, ).…”

“…Degradation can occur under both aerobic and anaerobic conditions (Cortinas et al, ; Guzmán‐Fierro et al, ; Mafla et al, ; Stolz et al, ), and the rate of degradation is related to the initial ROX concentration in soil (Liu, Zhang, Li, Wen, et al, ). Degradation is faster in anaerobic conditions than in aerobic conditions, with ROX being completely degraded after 48 hr of dark anaerobic incubation, while only 79.9% and 94.5% were degraded after 288 hr of dark aerobic and light aerobic incubation, respectively (Liu, Zhang, Li, Wen, et al, ). Light and microbial action are the main factors responsible for ROX degradation, which is also controlled by environmental factors such as moisture, temperature, and the organic content of the vadose zone (Fu, Blaney, & Zhou, ; Katherine et al, ; Sun, ).…”