| 摘要: |
| 挖掘适用于农田镉（Cadmium，Cd）污染修复的高耐镉功能菌株，可明确其对水稻Cd胁迫的缓解效应。本研究从广西矿区镉污染土壤中分离筛选耐镉菌株，通过形态学、生理生化特征与16S rDNA基因序列分析法进行鉴定，系统测定菌株的耐镉特性、环境适应性与植物促生潜能，并采用种子萌发和盆栽试验评价其对水稻镉污染的缓解促生效果。结果分离获得一株高耐镉优势菌株，最高可耐受1 400 mg/L Cd²?，经鉴定为Cellulosimicrobium cellulans，命名为C1。菌株C1在pH值为5.0-10.0、NaCl浓度为0-100 g/L条件下均可生长，环境适应性强，且可通过胞外吸附来钝化Cd²?。此外，菌株C1还具有产氨基环丙烷羧基（ACC）脱氨酶的植物促生活性；Cd胁迫会显著抑制水稻种子萌发与苗期生长，而接种菌株C1后可使水稻种子萌发率由20.00%恢复至52.50%，且苗期中水稻株高、根长、鲜重与干重均较Cd胁迫组显著回升，生长状态基本恢复至对照水平。综上，菌株C1具有高Cd耐受性、吸附钝化能力及产ACC脱氨酶功能，可有效缓解Cd对水稻的毒害作用，在Cd污染农田的微生物修复中具有良好应用潜力。 |
| 关键词: 镉污染 纤维微菌 耐镉特性 植物促生 水稻 |
| DOI： |
| 投稿时间：2026-05-05修订日期：2026-08-06 |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Isolation, Identification of Cadmium-tolerant Strain Cellulosimicrobium cellulans C1 and Its Alleviating Effect on Cadmium Contamination in Rice |
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JI Chunxi1,2, WANG Xuan1,2, WANG Xuan1,2, LU Junming1,2, SHEN Naikun1,2, ZHANG Hongyan1,2
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| (1.Guangxi Key Laboratory of Polysaccharide Materials and Modification,School of Marine Sciences and Biotechnology,Guangxi Minzu University,Nanning;2.China) |
| Abstract: |
| This study aimed to identify a highly cadmium (Cd)-tolerant functional bacterial strain suitable for the remediation of Cd-contaminated farmland and to elucidate its capacity to alleviate Cd-induced phytotoxicity in rice (Oryza sativa). Cd-resistant bacterial strains were isolated and screened from Cd-polluted soils collected from mining-affected areas in Guangxi Province, China. Strain identification was conducted based on morphological and physiological-biochemical characteristics, supplemented by 16S rDNA gene sequence analysis. The selected strain’s Cd tolerance, environmental adaptability, and plant growth-promoting traits were systematically evaluated. Seed germination assays and pot-based experiments were performed to assess the strain’s efficacy in mitigating Cd toxicity and enhancing rice growth under Cd stress. A dominant, highly Cd-tolerant strain, designated C1, was successfully isolated; it exhibited robust resistance to Cd2＋ at concentrations up to 1,400 mg/L and was identified as Cellulosimicrobium cellulans C1. Strain C1 demonstrated broad environmental adaptability, growing vigorously across a pH range of 5.0–10.0 and in the presence of NaCl concentrations ranging from 0 to 100 g/L. Furthermore, it effectively immobilized Cd2＋ via extracellular adsorption. Notably, C1 produced 1-aminocyclopropane-1-carboxylate (ACC) deaminase, an enzyme known to lower endogenous ethylene levels in plants and thereby promote growth under abiotic stress. Cd stress severely inhibited rice seed germination and early seedling development; however, inoculation with strain C1 significantly restored germination rates, from 20.00% under Cd-only treatment to 52.50%. Furthermore, key growth parameters, including plant height, root length, fresh weight, and dry weight, were markedly improved relative to the Cd stress group and approached those of the unstressed control. In summary, C. cellulans C1 is a highly promising microbial candidate for Cd bioremediation. Its integrated functional attributes, including extraordinary Cd tolerance, efficient extracellular Cd immobilization, and ACC deaminase–mediated promotion of plant growth under stress, enable effective mitigation of Cd toxicity in rice. This strain holds substantial potential for application in the microbial remediation of Cd-contaminated agricultural soils. |
| Key words: cadmium pollution Cellulosimicrobium cadmium tolerance plant growth promotion Oryza sativa |
