1株分离自煤矿废水的铁硫氧化细菌LY01的鉴定及其氧化特性研究

从贵州省某煤矿废水中分离出1株嗜酸性的铁硫氧化细菌菌株LY01,经过对该菌株的形态特征、理化特征检测及16S rRNA序列分析,初步鉴定菌株LY01为嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans).在无机盐培养液中菌株LY01可以从氧化Fe2+、单质硫(S0)及黄铁矿(FeS2)获得能量生长,对Fe2+的氧化速率最快,反应30 h即可将44.2 g.L-1的FeSO4.7H2O完全氧化,菌体细胞达到4.2×107个.mL-1;反应21 d可将溶液中10 g.L-1含量的S0氧化6.7%,溶液中SO24-浓度达2 001 mg.L-1,菌体细胞达到8.9×107个.mL-1;反应20 d可将溶液中30 g.L-1含量的FeS2氧化10%,溶液中SO24-浓度达4 443 mg.L-1,菌体细胞达到3.4×108个.mL-1.研究重金属离子Ni2+、Pb2+对菌株LY01氧化FeS2活性的影响,结果发现10～100 mg.L-1的Ni2+对菌株LY01氧化FeS2活性有一定的影响,而10～100 mg.L-1Pb2+对菌株LY01氧化FeS2的活性无影响.

Isolation, Identification and Oxidizing Characterization of an Iron-Sulfur Oxidizing Bacterium LY01 from Acid Mine Drainage

An acidophilic iron-sulfur oxidizing bacterium LY01 was isolated from acid mine drainage of coal in Guizhou Province, China. Strain LY01 was identified as Acidithiobacillus ferrooxidans by morphological and physiological characteristics, and phylogenetic analysis of its 16S rRNA gene sequence. Strain LY01 was able to grow using ferrous ion (Fe²⁺), elemental sulfur (S⁰) and pyrite as sole energy source,respectively, but significant differences in oxidation efficiency and bacterial growth were observed when different energy source was used. When strain LY01 was cultured in 9K medium with 44.2 g·L^-1 FeSO₄·7H₂O as the substrate, the oxidation efficiency of Fe²⁺ was 100% in 30 h and the cell number of strain LY01 reached to 4.2×10⁷ cell·mL^-1. When LY01 was cultured in 9K medium with 10 g·L^-1 S⁰ as the substrate, 6.7% S⁰oxidation efficiency, 2001 mg·L^-1 SO₄^2- concentration and 8.9×10⁷ cell·mL^-1 cell number were observed in 21 d respectively. When LY01 was cultured with 30 g·L^-1 pyrite as the substrate, the oxidation efficiency of pyrite, SO₄^2- concentration and cell number reached 10%, 4443 mg·L^-1 and 3.4×10⁸ cell·mL^-1 respectively in 20 d. The effects of different heavy metals (Ni²⁺, Pb²⁺) on oxidation activity of strain LY01 cultured with pyrite were investigated. Results showed that the oxidation activity of strain LY01 was inhibited to a certain extent with the addition of Ni²⁺ at 10-100 mg·L^-1to the medium, but the addition of 10-100 mg·L^-1 Pb²⁺had no effect on LY01 activity.