重金屬對(duì)其鐵氧化能力影響的評(píng)估
(1. 湖南科技大學(xué) 生命科學(xué)學(xué)院，湘潭 411201；2. 中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用稀釋分離法，從山西中條山銅礦的酸性礦坑水中分離出一株鐵氧化細(xì)菌，命名為ZTS菌株。該菌株為革蘭氏陰性細(xì)菌，螺旋狀或弧狀，最適生長(zhǎng)溫度為30 ℃，最適生長(zhǎng)pH值為2.5，對(duì)低濃度的酵母浸出物較敏感。形態(tài)學(xué)和生理學(xué)分析表明，ZTS菌株可能屬于鉤端螺旋菌屬的成員；16S rDNA序列的系統(tǒng)發(fā)育分析表明，該菌株與氧化亞鐵鉤端螺旋菌典型菌株ATCC 49879位于系統(tǒng)發(fā)育樹(shù)的同一分支，相似度為100%，從而證實(shí)ZTS菌株屬于氧化亞鐵鉤端螺旋菌。考慮到當(dāng)前的商業(yè)利益，考察了Cu2+、Co2+ 和Ni2+對(duì)ZTS菌株氧化亞鐵能力的影響。結(jié)果表明：3種金屬對(duì)ZTS菌株的毒性強(qiáng)弱依次為Co2+＞Cu2+＞Ni2+。就Ni2+抗性能力而言，ZTS菌株能夠耐受Ni2+的濃度高達(dá)160 mmol/L，這比已報(bào)道的氧化亞鐵鉤端螺旋菌的Ni2+抗性能力要強(qiáng)得多，這種能力可能與它的遺傳特性有關(guān)。
關(guān)鍵字: 酸性礦坑水；氧化亞鐵鉤端螺旋菌；鐵氧化能力；重金屬抗性
（1. School of Life Science, Hunan University of Science and Technology, Xiangtan 411201, China;
2. School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:Using a dilution method, an iron-oxidizing bacterium, designated strain ZTS, was isolated from acid mine drainage of Zhongtiaoshan Copper Mine, Shanxi Province, China. Cells of strain ZTS were spiral or curved-shaped, gram-negative, and the optimum temperature was 30 ℃ and the optimum pH was 2.5. The strain ZTS was sensitive to low concentration of yeast extract. The cell shape, physiological characteristics and 16S rDNA sequence analysis indicated that the strain ZTS should belong to the species of Leptospirillum ferrooxidans. Considering its recent commercial interest, the effects of copper (Cu2+), cobalt (Co2+) and nickel (Ni2+) on strain ZTS were investigated during the oxidation of a ferrous iron solution (40 g/L). The results show that copper, cobalt and nickel individually inhibit the ferrous iron oxidation in the order Co2+＞Cu2+＞Ni2+. Interestingly, the nickel resistance capability of strain ZTS, which can resist nickel of 160 mmol/L, is much stronger than that of Leptospirillum ferrooxidans reported ago. This ability of strain ZTS may be relevant to its genetic characteristics.
Key words: acid mine drainage; Leptospirillum ferrooxidans; iron oxidation ability; heavy metal resistance
