摘要
为了解施用鸡粪有机肥对土壤中重金属含量变化及细菌对重金属抗性的影响,从西南地区某大型鸡场采集鸡粪、鸡粪有机肥及其施用土壤,测定其重金属含量,分离鉴定可培养细菌,测定细菌对重金属抗性表型,选择多重抗性的菌株进行全基因组测序分析。研究结果显示鸡粪有机肥中重金属含量符合相关标准,鸡粪有机肥的长期施用显著增加了土壤中锌(Zn)、锰(Mn)和铅(Pb)的含量,其中连续施肥3年显著增加土壤中的Zn和Mn的含量,连续施肥6年则提升了土壤中Zn和Pb的含量。从样品中分离出93株细菌,其中芽孢杆菌为分离菌株中的优势属(n=25,26.88%)。分离的菌株对铜Cu(56.99%,53/93)和Zn(70.00%,65/93)表现出较高的抗性,施肥3年显著使细菌对Cu的抗性增强,而施肥6年则进一步增强了细菌对Zn、镉(Cd)、Cu和Pb的抗性。全基因组测序发现蜡样芽孢杆菌携带与Cu、Zn、Mn和Cd抗性直接相关的基因,且这些基因的存在与菌株的抗性表型高度一致。连续施肥源菌株中注释到更多的重金属抗性基因,包括Mn抗性基因簇mntA-mntB-1-mntB-2、砷(As)抗性基因arsR-1和arsR-2以及Cd抗性基因cadI-1和cadI-2,重金属的积累可能诱导细菌进化出更多的抗性基因。该研究对开展有机肥及其施用土壤中重金属抗性菌株污染监测具有重要意义,对科学施用有机肥和维持农业生产安全具有指导作用。
To understand the effect of organic chicken manure fertilizer on soil heavy metal contents and bacterial resistance,chicken manure,organic fertilizer,and fertilized soil samples were collected from a large poultry farm in Southwestern China.Heavy metal contents were measured,and cultivable bacteria were isolated and identified.In addition,the resistance phenotypes of the isolated bacteria were assessed.Whole-genome sequencing was p erformed on multi-resistant strains.Results showed that heavy metal levels in the organic fertilizer met relevant standards.Long-term application of organic fertilizer significantly increased the contents of soil zinc(Zn),m anganese(Mn),and lead(Pb).Specifically,three years’fertilization increased the contents of soil Zn and Mn,while six years increased Zn and Pb.A total of 93 bacterial strains were isolated,and with Bacillus as the dominant genus(n=25,26.88%).High resistance to Cu(56.99%,53/93)and Zn(70.00%,65/93)was observed.Fertilization for three years enhanced Cu resistance,while six years further increased resistance to Zn,cadmium(Cd),Cu,and Pb.Whole-genome sequencing of Bacillus cereus revealed resistance genes related to Cu,Zn,Mn,and Cd were consistent with the resistance phenotypes.Strains from continuously fertilized soil had more heavy metal resistance genes,including the Mn gene cluster mntA-mntB-1-mntB-2,arsenic(As)genes arsR-1 and arsR-2,and Cd genes cadI-1 and cadI-2.Heavy metal accumulation probably induced bacterial evolution or acquisition of resistance genes.This study highlights the importance of monitoring heavy metal-resistant bacteria in organic fertilizers and fertilized soils,providing insights for sustainable fertilizer application.
作者
邓国游
闫敏
谭玉兰
戢林
赵珂
邹立扣
DENG Guoyou;YAN Min;TAN Yulan;JI Lin;ZHAO Ke;ZOU Likou(College of Resources,Sichuan Agricultural University,Chengdu 611130,China;School of Life Sciences,Guizhou Normal University,Guiyang 550025,China)
出处
《生态毒理学报》
北大核心
2025年第6期352-364,共13页
Asian Journal of Ecotoxicology
关键词
重金属
土壤
重金属抗性基因
重金属抗性菌株
鸡粪有机肥
heavy metals
soil
heavy metal resistance genes
heavy metal resistant strains
organic chicken manure fertilizer
