一株耐铜细菌TLSB_2-K的鉴定及其铜吸附能力

Identification and Absorption Ability of Copper- resistant Bacteria TLSB_2- K

通过形态观察、革兰氏染色和16Sr DNA序列比对,对前期分离的菌株TLSB2-K进行了鉴定,并采用振荡培养法,探讨了温度、p H值和渗透压对菌株生长的影响,以及铜胁迫下菌株对铜的耐性及吸附能力。结果表明,TLSB2-K属于芽孢杆菌属,其最适生长条件为：温度27℃、p H值7、渗透压1.1%Na Cl。铜胁迫下菌株生长周期缩短。铜浓度在100~500 mg/L的范围内,菌体生长良好,铜浓度为100 mg/L时胁迫培养25 h,菌体铜含量为1 253.4 mg/kg;铜浓度为200 mg/L和300 mg/L时胁迫培养30 h,菌体铜含量分别达到2 087.2 mg/kg和2 188.4 mg/kg;菌株的最高铜耐受浓度为700 mg/L。实验结果证实,菌株TLSB2-K具有较强的铜耐性和较高的铜吸附能力,其具有重要的理论研究和工程应用价值。

A bacterial strain TLSB2 - K separated in earlier stage was identified by morphological observation, gram stain and 16SrDNA sequence alignment. The influence of temperature ,pH value and osmotic pressure to the bacterial strain＇s growth, and the capability of endurance and absorption for copper under copper stress conditions were explored by the method of shaking culture. The result showed that strain TLSB2 - K was pri- marily identified as Bacillus sp. from its morphological, its optimum temperature was 27 ℃, optimum pH was 7 and it grew best under 1.1% NaC1. The growth cycle was shortened under the copper stress condition. Strains grew well in copper concentration of 100 -500 mg/L. when cultivated them about 25 hours in 100 mg/L copper concentration, the strains＇copper content would reach to 1 253.4 mgcZkg. While cultivated them about 30 hours and the copper concentration were in 200 and 300 mg/L,the copper content of TLSB2 -K were 2 087.2 mg/kg and 2 188.4 mg/kg respectively. What the highest copper concentration TLSB2 - K could live in was 700 mg/L. All of these confirmed that TLSB2 - K had a strong capability of copper endur- ance and absorption,which showed a great significance in theoretical research and engineering practice.