一株耐镉促生细菌Achromobacter sp.A81的分离鉴定及特性  

Isolation,identification,and characterization of a cadmium-tolerant bacterium Achromobacter sp.A81 with plant growth-promoting effect

作　　者：陆君铭 吉春喜 郭健杰 刘睿 张莉刚 殷豆豆 唐家昊 张红岩 申乃坤 LU Junming;JI Chunxi;GUO Jianjie;LIU Rui;ZHANG Ligang;YIN Doudou;TANG Jiahao;ZHANG Hongyan;SHEN Naikun(Guangxi Key Laboratory for Polysaccharide Materials and Modification,School of Marine Sciences and Biotechnology,Guangxi Minzu University,Nanning 530006,Guangxi,China)

机构地区：[1]广西民族大学海洋与生物技术学院,广西多糖材料与改性重点实验室,广西南宁530006

出　　处：《微生物学报》2025年第1期90-105,共16页Acta Microbiologica Sinica

基　　金：国家自然科学基金(32160017);广西壮族自治区科技重大专项(AB21196019,AB21220020);广西民族大学引进高层次人才科研项目(2018KJQD17);广西民族大学国家级大学生创新创业项目(202410608026)。

摘　　要：【目的】从广西某矿区污染土中筛选并鉴定耐镉(cadmium,Cd)促生细菌,评估其耐Cd、去Cd^(2+)效率、促生特性及对Cd胁迫下水稻生长的影响,展现其在植物促长与土壤修复中的潜力。【方法】通过稀释涂布和Cd^(2+)浓度梯度驯化分离耐Cd细菌,进一步通过形态学、生理生化及16S r RNA基因系统发育树法进行鉴定;再运用微量稀释法、电感耦合等离子体质谱法、比色法测定菌株的耐Cd能力、去Cd^(2+)效率和植物促生特性;最后通过盆栽试验考察施加菌株后对Cd胁迫下水稻生长的影响。【结果】从重金属污染土壤中分离得到12株对Cd^(2+)表现较好抗性的细菌,其中对Cd耐受最好的一株细菌鉴定并命名为无色杆菌属(Achromobacter sp.)A81,其对Cd^(2+)的耐受浓度高达800 mg/L,在10 mg/L Cd^(2+)浓度下培养7 d,其最大Cd^(2+)去除率为44.66%;菌株A81的上清液和菌体可共同吸附Cd^(2+);在Cd胁迫下分泌大量胞外聚合物(extracellular polymeric substance,EPS),主要成分为不溶性和可溶性蛋白。此外,该菌株具有固氮、溶磷、产铁载体、吲哚乙酸(indole-3-acetic acid,IAA)和1-氨基环丙烷-1-羧酸(1-aminocyclopropane-1-carboxylic acid,ACC)脱氨酶等植物促生活性,展现出显著的促生潜力。盆栽试验结果表明,与Cd胁迫组的对照相比,接种菌株A81后水稻的株高、根长、茎粗和鲜重分别增加了9.08%、39.59%、41.94%和73.58%。【结论】本研究探究了Achromobacter sp.A81在耐Cd、除Cd与植物促生方面的特性,以及其在Cd污染土壤修复中的应用潜力,为微生物治理重金属污染与农业绿色发展提供科学依据与优质菌株资源。[Objective]To screen and identify cadmium(Cd)-tolerant bacteria with plant growth-promoting effect from contaminated soil of a mining area in Guangxi,characterize the strain screened out in terms of the Cd tolerance,Cd^(2+)removal efficiency,plant growth-promoting effect,and influence on rice growth under Cd stress,and demonstrate the potential of the strain in plant growth and soil remediation.[Methods]Cd-tolerant bacteria were isolated by the dilution coating method and Cd^(2+)concentration gradient acclimation and further identified based on the morphological,physiological,biochemical characteristics and the 16S rRNA gene phylogenetic tree.The Cd tolerance,Cd^(2+)removal efficiency,and plant growth-promoting effect of the target strain were measured by microdilution,inductively coupled plasma mass spectrometry,and colorimetry.Finally,the effect of the strain on the growth of rice plants under Cd stress was investigated by a pot experiment.[Results]Twelve strains of bacteria with good tolerance to Cd^(2+)were isolated from heavy metal-contaminated soil,and one strain with the best tolerance to Cd was identified as Achromobacter sp.A81,which could grow in the presence of 800 mg/L Cd^(2+).Strain A81 cultured with 10 mg/L Cd²+for 7 days showed the maximum Cd²+removal rate of 44.66%.Both the supernatant and cells of strain A81 demonstrated the ability to adsorb Cd^(2+).Under Cd stress,the strain secreted a large amount of extracellular polymeric substances(EPS)primarily composed of insoluble and soluble proteins.Furthermore,this strain was capable of fixing nitrogen,solubilizing phosphorus,and secreting siderophores,indole-3-acetic acid(IAA),and 1-aminocyclopropane-L-carboxylate(ACC)deaminase,demonstrating remarkable plant growth-promoting effect.Pot experiment results revealed that compared with the group subjected to Cd stress,the rice plants inoculated with strain A81 showed increases of 9.08%,39.59%,41.94%,and 73.58%in plant height,root length,stem diameter,and fresh weight,respectively.[Conclusion]This study

关 键 词：耐镉 无色杆菌属 植物促生 镉胁迫 水稻盆栽 

分 类 号：X172[环境科学与工程—环境科学] X53