The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost ...The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost toxic cyanotoxin,microcystin-LR(MC-LR)enter soil via runoff,irrigated surface water and sewage,and the application of cyanobacterial biofertilizers as part of the sustainable agricultural practice.Earthworms in such remediation systems must sustain the potential risk from both nZVI and MC-LR.In the present study,earthworms(Eisenia fetida)were exposed up to 14 days to MC-LR and nZVI(individually and inmixture),and the toxicity was investigated at both the organismal andmetabolic levels,including growth,tissue damage,oxidative stress,metabolic response and gut microbiota.Results showed that co-exposure of MC-LR and nZVI is less potent to earthworms than that of separate exposure.Histological observations in the co-exposure group revealed only minor epidermal brokenness,and KEGG enrichment analysis showed that co-exposure induced earthworms to regulate glutathione biosynthesis for detoxification and reduced adverse effects from MC-LR.The combined use of nZVI promoted the growth and reproduction of soil and earthworm gut bacteria(e.g.,Sphingobacterium and Acinetobacter)responsible for the degradation of MC-LR,whichmight explain the observed antagonism between nZVI and MC-LR in earthworm microcosm.Our study suggests the beneficial use of nZVI to detoxify pollutants in earthworm-based vermiremediation systems where freshwater containing cyanobacterial blooms is frequently used to irrigate soil and supply water for the growth and metabolism of earthworms.展开更多
基金supported by the National Natural Science Foundation of China(No.21777139)the National Key Research and Development Program of China(No.2017YFA0207003).
文摘The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost toxic cyanotoxin,microcystin-LR(MC-LR)enter soil via runoff,irrigated surface water and sewage,and the application of cyanobacterial biofertilizers as part of the sustainable agricultural practice.Earthworms in such remediation systems must sustain the potential risk from both nZVI and MC-LR.In the present study,earthworms(Eisenia fetida)were exposed up to 14 days to MC-LR and nZVI(individually and inmixture),and the toxicity was investigated at both the organismal andmetabolic levels,including growth,tissue damage,oxidative stress,metabolic response and gut microbiota.Results showed that co-exposure of MC-LR and nZVI is less potent to earthworms than that of separate exposure.Histological observations in the co-exposure group revealed only minor epidermal brokenness,and KEGG enrichment analysis showed that co-exposure induced earthworms to regulate glutathione biosynthesis for detoxification and reduced adverse effects from MC-LR.The combined use of nZVI promoted the growth and reproduction of soil and earthworm gut bacteria(e.g.,Sphingobacterium and Acinetobacter)responsible for the degradation of MC-LR,whichmight explain the observed antagonism between nZVI and MC-LR in earthworm microcosm.Our study suggests the beneficial use of nZVI to detoxify pollutants in earthworm-based vermiremediation systems where freshwater containing cyanobacterial blooms is frequently used to irrigate soil and supply water for the growth and metabolism of earthworms.
