一株Tl^+抗性菌株的鉴定及吸附特性

Identification and biosorption characterization of a thallium-resistant strainIdenti cation and biosorption characterization of a thallium-resistant strain

为了获得吸附铊(Tl)的功能菌株以应用于实际工业废水处理,从某矿区土壤中分离筛选出一株抗Tl+细菌BSA-68,对其进行了初步鉴定,并对其Tl+吸附特性和初步机理进行了研究.16S rDNA序列分析表明,该菌株属于假单胞菌,命名为Pseudomonas sp.BSA-68(登录号:JF901709).该菌株最大抗Tl+浓度为30 mg/L,溶液初始浓度、pH值、吸附时间、摇床转速及菌体生物量对Tl+吸附具有一定的影响,菌株在Tl+初始浓度20 g/L,吸附时间30 min,pH 6.0,摇床转速150 r/min,生物量2.0 g/L时,吸附效果最佳,在该条件下,BSA-68菌株对Tl+的吸附率可达93.77%.红外光谱分析表明,该菌株细胞壁中的羟基、羧基及氨基是对Tl+吸附起主要贡献的官能团.研究结果表明,BSA-68菌株可作为经济、高效、环境友好的生物材料进行Tl+废水处理.

This study aimed to obtain functional strains adsorbing thallium for application in industrial wastewater treatment. A thallium resistant bacterium BSA-68 strain was isolated from mining soil, preliminarily identified, and its Tl＋ biosorption characteristics analyzed. The 16S rDNA sequence analysis revealed that the strain belonged to Pseudomonas sp. （accession number JF901709）, therefore named as Pseudomonas sp. BSA-68. The strain possessed the capability of Tl＋ resistance up to 30 mg/L in aqueous solution. The initial concentration of the solution, pH, adsorption time, speed and biomass all had certain degree of effect on Tl＋ biosorption. The result showed that the optimum conditions for maximum biosorption were pH of 6.0 with biomass of 2.0 g/L, initial Tl＋ concentration of 20 g/L, rotation 150 r/min and contact time of 30 min. Under such conditions, the adsorption rate could reach 93.77%. The Fourier transform infrared spectroscopy （FT-IR） analysis indicated that the main functional groups responsible for biosorption of thallium were hydroxyl, carboxyl and amino groups. The results presented in this study showed that the strain BSA-68 could be used as an effective, low cost biosorbent for the removal of thallium from waste water.