• 关键词：耐镉细菌  重金属离子  吸附  红外光谱

• 基金项目：

• 刘爱民
• 1. 农业部农业环境微生物工程重点开放实验室, 南京农业大学生命科学学院微生物学系, 南京 210095; 2. 安徽师范大学生命科学学院, 芜湖 241000

• 黄为一
• 农业部农业环境微生物工程重点开放实验室, 南京农业大学生命科学学院微生物学系, 南京 210095

• 摘要：从安徽某冶炼厂污染土壤中分离出一株能耐高浓度镉的菌株(J₅),经初步鉴定为假单胞菌属(Pseudomonas sp.).该菌株在液体培养基中耐受40mmol.L^-1 CdSO₄,在固体培养基上耐受75mmol.L^-1 CdSO₄.培养基中Cd²⁺、Zn²⁺、Pb²⁺、Cu²⁺浓度分别为100mg.L^-1和Mn²⁺浓度为275mg.L^-1时,菌株生长正常.在重金属Cu²⁺、Pb²⁺、Zn²⁺、Mn²⁺存在时,采用红外光谱与原子吸收光谱分析菌株对Cd²⁺的积累,结果表明,在低浓度Cd²⁺溶液中菌株细胞对Cd²⁺的积累,主要靠细胞壁上—NH₂与Cd²⁺配位结合;在高浓度Cd²⁺溶液中,细胞壁上—NH₂、—OH、—COOH、—PO₄^3-、—M—O(O—M—O)基团吸附Cd²⁺的能力显著.Mn²⁺可以增加细胞壁上有效官能团活性,提高Cd²⁺积累率;但当有Zn²⁺、Pb²⁺、Cu²⁺重金属离子共存时,即使有Mn²⁺存在,菌体对Cd²⁺吸附积累能力未见提高.

• Abstract：Atoletant-cadmium strain J5, isolated from the polluted soil around the smeltery in Anhui province, was identified as Pseudomonas sp. strain. It can tolerate 40 mmol·L^-1 cadmium sulphate in liquid medium and 75 mmol·L^-1Cd²⁺ in solid medium. The strain grew normal in the presence of 100 mg·L^-1 of Cd²⁺, Zn²⁺, Pb²⁺, Cu²⁺ and 275 mg·L^-1 of Mn²⁺, respectively. The accumulation to Cd²⁺ in the strain was observed by infrared spectroscopy and atomic absorption spectroscopy, in the presence of Cu²⁺, Pb²⁺, Zn²⁺, Mn²⁺. The results indicated that in low Cd²⁺ concentration, —NH₂ group on the cell wall mostly match with Cd²⁺. When in high Cd²⁺ concentration, —NH₂, —OH, —COOH, —PO₄^3- and —M—O(O—M—O)groups strongly adsorbed Cd²⁺. Mn²⁺ increased the activity of the groups mentioned above, and facilitated the accumulation of Cd²⁺ on the cell wall. In contrast, Zn²⁺, Pb²⁺, Cu²⁺ ions coexisting decreased such adsorption and accumulation, even if in the presence of Mn²⁺.

• Key words：tolerant-cadmium bacterium  heavy metal ions  adsorption  Infrared spectroscopy

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