College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China.
Faculty of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, PR China.
J Hazard Mater. 2022 Mar 5;425:127778. doi: 10.1016/j.jhazmat.2021.127778. Epub 2021 Nov 14.
Atrazine accumulation in agricultural soil is prone to cause serious environmental problems and pose risks to human health. Vermicomposting is an eco-friendly approach to accelerating atrazine biodegradation, but the roles of earthworm cast in the accelerated atrazine removal remains unclear. This work aimed to investigate the roles of earthworm cast in promoting atrazine degradation performance by comprehensively exploring the change in atrazine metabolites and bacterial communities. Our results showed that earthworm cast amendment significantly increased soil pH, organic matters, humic acid, fulvic acid and humin, and achieved a significantly higher atrazine removal efficiency. Earthworm cast addition also remarkably changed soil microbial communities by enriching potential soil atrazine degraders (Pseudomonadaceae, Streptomycetaceae, and Thermomonosporaceae) and introducing cast microbial degraders (Saccharimonadaceae). Particularly, earthworm casts increased the production of metabolites deethylatrazine and deisopropylatrazine, but not hydroxyatrazine. Some bacterial taxa (Gaiellaceaea and Micromonosporaceae) and humus (humic acid, fulvic acid and humin) were strongly correlated with atrazine metabolism into deisopropylatrazine and deethylatrazine, whereas hydroxyatrazine production was benefited by higher pH. Our findings verified the accelerated atrazine degradation with earthworm cast supplement, providing new insights into the influential factors on atrazine bioremediation in vermicomposting.
阿特拉津在农业土壤中的积累容易导致严重的环境问题，并对人类健康构成威胁。蚯蚓堆肥是加速阿特拉津生物降解的一种环保方法，但蚯蚓粪在加速阿特拉津去除中的作用尚不清楚。本研究旨在通过综合探索阿特拉津代谢物和细菌群落的变化，研究蚯蚓粪在促进阿特拉津降解性能中的作用。研究结果表明，蚯蚓粪改良剂显著提高了土壤 pH 值、有机质、腐殖酸、富里酸和胡敏素，实现了更高的阿特拉津去除效率。蚯蚓粪的添加还通过富集潜在的土壤阿特拉津降解菌（假单胞菌科、链霉菌科和Thermomonosporaceae）和引入蚯蚓粪微生物降解菌（Saccharimonadaceae）显著改变了土壤微生物群落。特别是，蚯蚓粪增加了脱乙基阿特拉津和脱异丙基阿特拉津的代谢产物的产生，但没有羟基阿特拉津。一些细菌类群（盖尔氏菌科和微单胞菌科）和腐殖质（腐殖酸、富里酸和胡敏素）与阿特拉津代谢为脱异丙基阿特拉津和脱乙基阿特拉津呈强烈正相关，而羟基阿特拉津的产生则得益于较高的 pH 值。本研究验证了蚯蚓粪补充加速了阿特拉津的降解，为蚯蚓堆肥中阿特拉津生物修复的影响因素提供了新的见解。
