Identification and Cu Enrichment Capacity of TLSB_2-K, a Cu-tolerant Strain

耐铜菌株TLSB_2-K的鉴定及其铜富集能力测定(英文)

[Objective] The Cu-tolerance and Cu enrichment capacity of TLSB2-K were investigated. [Method] The previously isolated TLSB2-K strain was identified though morphological observation, gram staining and 16S rDNA sequence alignment. In ad- dition, the effects of temperature, pH and osmotic pressure on the growth of strain were also investigated by using shaking culture. The Cu-tolerance and Cu enrich- ment capacity of TLSB2-K strain under Cu stress were also studied. [Result] The results showed TLSB2-K belongs to Bacillus spp., and its optimum growth conditions were as follows： temperature, 27 ~C; pH, 7.0; osmotic pressure, 1.1% NaCI. When the Cu concentration ranged from 100 mg/L to 500 mg/L, the strain grew well; when the Cu concentration ranged from 100 mg/L to 400 mg/L, the Cu content in bacteria was increased with the increase of Cu concentration; when the Cu con- centration was 400 mg/L and the incubation time was 30 h, the Cu content in bac- teria reached the peak （2 250 mg/kg）; the highest tolerant concentration was 700 mg/L. [Conclusion] TLSB2-K strain had relatively high Cu tolerance and Cu enrich- ment capacity. They had important theoretical research and engineering application values.

[目的]研究菌株TLSB2-K的铜耐性以及其铜富集能力的特性。[方法]通过形态观察、革兰氏染色和16S r 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富集能力。[结果]TLSB2-K属于蜡样芽孢杆菌（Bacillus cereus）,最适生长条件为：温度为27℃、p H值为7、渗透压为1.1%Na Cl。铜浓度100~500 mg/L范围内,菌体生长良好,铜浓度在100~400 mg/L范围内,菌体铜含量随着铜浓度的升高而增加,当铜浓度400 mg/L胁迫培养30 h,菌体铜含量达到最大值2 250mg/kg;菌株的最高铜耐受浓度为700 mg/L。[结论]菌株TLSB2-K具有较强的铜耐性和较高的铜富集能力,具有重要的理论研究和工程应用价值。