农业环境科学学报2025，Vol.44Issue(6)：1486-1496,11.DOI:10.11654/jaes.2025-0438
胞外聚合物介导的Pantoea dispersa对高浓度铜和镉的耐受机制
Mechanisms of extracellular polymeric substances-mediated copper and cadmium tolerance in Pantoea dispersa
摘要
Abstract
To explore the survival strategies of microorganisms in response to heavy metal stress,clarify the functions of extracellular polymeric substances(EPS)in the heavy metal tolerance of microorganisms,and reveal the differences in tolerance mechanisms to different heavy metals,this study measured the EPS production of Pantoea dispersa MSC14 and revealed the role of EPS in the tolerance mechanisms by comparing the changes in physiological indicators before and after EPS removal.Furthermore,transcriptomics elucidated the different tolerance mechanisms between Cu2+and Cd2+.The results showed that strain MSC14 still exhibited considerable metabolic activity under 300 mg∙L-1 Cu2+and Cd2+.Meanwhile,the content of EPS increased significantly.Under Cu2+stress,the contents of polysaccharides and proteins increased to 19.0-fold and 9.3-fold respectively at the highest,while under Cd2+stress,they increased by 5.8-fold and 7.8-fold respectively at the highest.The extracellular adsorption by strain MSC14 was significantly higher than intracellular accumulation.After removing EPS,the total accumulation decreased by 49.8%-52.0%and 40.0%-68.6%respectively,while the degree of oxidative stress was aggravated.KEGG pathway analysis indicated that Cu2+induced nitrogen metabolism,facilitating the reduction of Cu2+to Cu+,while Cd2+enhanced small molecule synthesis and transport.This suggested that Cd2+improved tolerance through intracellular precipitation and efflux.In summary,EPS serves as an important barrier for strain MSC14 to tolerate Cu2+and Cd2+.Meanwhile,the strain has developed distinct specific tolerance strategies for Cu2+and Cd2+.关键词
Cu2+/Cd2+/胞外聚合物/Pantoea dispersa MSC14/生理响应/转录组学Key words
Cu2+/Cd2+/extracellular polymeric substances/Pantoea dispersa MSC14/physiological response/transcriptomics分类
资源环境引用本文复制引用
宋雨欣,袁梦,陈国涛,谢光虹,朱崇岭,崔堂兵,任源..胞外聚合物介导的Pantoea dispersa对高浓度铜和镉的耐受机制[J].农业环境科学学报,2025,44(6):1486-1496,11.基金项目
国家重点研发计划项目(2020YFC1808803) National Key Research and Development Program of China(2020YFC1808803) （2020YFC1808803）
