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| 微生物生物吸附重金属性能及生理学机理研究 |
| Study on the Performance and Physiological Mechanism of Microbial Biosorption of Heavy Metals |
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| DOI：doi:10.3969/j.issn.1005-7021.2025.03.008 |
| 中文关键词: 微生物 重金属 生物吸附 细胞膜通透性 细胞壁 吸附机理 |
| 英文关键词: microorganism heavy metals biosorption cell membrane permeability cell wall adsorption mechanism |
| 基金项目:甘肃省自然科学基金项目（24JRRA741）；兰州资源环境职业技术大学校级重大科研项目（X2022ZD-06）；甘肃省教育厅青年博士支持项目（2023QB-021） |
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| 中文摘要: |
| 为挖掘可高效吸附重金属的微生物资源及揭示其吸附、应答重金属胁迫机理，以一株从重金属污染土壤中分离出的嗜根寡养单胞菌（Stenotrophomonas rhizophila）为研究对象，分别研究了其对不同浓度和类型的金属离子的吸附性能。通过扫描电镜（SEM）观察、傅里叶红外光谱仪（FTIR）分析及膜通透性检测分别研究了菌株响应重金属胁迫时的生理学机理。结果表明，嗜根寡单胞菌对不同浓度的金属离子显示出差异性耐受和吸附，其中可耐受160 mg/L的Cr6+，但对120 mg/L的Cd2+的吸附能力最强，为93.4%。吸附方式主要为胞外吸附和表面吸附，过程符合准二级动力学和Freundlich模型。生理学机理研究表明，微生物可通过细胞伸长、缩小、在细胞表面形成团聚物等方式响应不同类型金属的胁迫。微生物的细胞膜在响应重金属胁迫时发挥类似“开关”的作用，其可通过控制细胞膜的通透性来适应重金属胁迫。嗜根寡单胞菌细胞壁中的-OH、-COOH、-C=O等参与细胞外对金属离子的吸附，尤其是-OH，对不同类型的金属离子均有结合能力。 |
| 英文摘要: |
| To investigate microbial resources capable of efficiently adsorbing heavy metals and to elucidate the physiological mechanisms underlying adsorption and responses to heavy metal stress, Stenotrophomonas rhizophila, isolated from heavy metal-contaminated soil, was selected as the research subject. The biosorption properties of S. rhizophila were examined across various concentrations and types of metal ions. Additionally, the physiological mechanisms by which the strain responds to heavy metal stress were analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and membrane permeability assessments. The results indicated that S. rhizophila could tolerate 160 mg/L of Cr6+, while its adsorption capacity for 120 mg/L of Cd2+ was the highest at 93.4%. The primary adsorption mechanisms identified were extracellular adsorption and surface adsorption, with the biosorption process of S. rhizophila conforming to pseudo-second-order kinetics and the Freundlich isotherm model. Furthermore, studies on physiological mechanisms revealed that microorganisms can respond to various types of metal stress through cell elongation, shrinkage, and the formation of aggregates on the cell surface. The cell membrane functions similarly to a "switch" in response to heavy metal stress, adapting to such stress by regulating membrane permeability. Moreover, functional groups such as -OH, -COOH, and -C=O in the strain′s cell wall are involved in the extracellular biosorption of metal ions, particularly -OH, which can bind to different types of metal ions. |
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