1株耐重金属细菌的筛选、鉴定及吸附性能研究

Screening and Identification of a Heavy Metal Resistant Bacterium and Its Biosorption Property

为了更加有效地对重金属污染环境进行生物修复,从Cd污染废水中分离到1株耐Cd的菌株DJ16,经形态观察、生理生化特性、脂肪酸组分及16S rRNA基因序列分析确定该菌株属于沙雷氏菌属(Serratia)。该菌株的重金属耐受性试验表明,菌株对Zn^(2+)的耐受性最强,Cd^(2+)次之,Cu^(2+)最差。菌株的重金属富集试验显示,菌株对Cu^(2+)、Zn^(2+)的吸附量随培养时间的增加先增加后降低,对Cu^(2+)的吸附量在培养12 h时最高,为6.8 mg/g,对Zn^(2+)的吸附量也在培养12 h时最高,为9.0 mg/g。菌株对Cd^(2+)的吸附量随培养时间的增加而增加,培养36 h时最高,为8.8 mg/g。综上,该菌株在生物修复方面具有很大的应用前景。

In order to effectively carry out bioremediation of heavy metals polluted enviroment,a Cd resistance strain DJ16 was isolated from Cd contaminated wastewater. On the basis of morphological observation,physiological and biochemical characteristics,fatty acid composition analysis and 16 S rRNA gene sequence analysis,the strain DJ16 was considered to represent a strain of the Serratia. The heavy metal tolerance tests showed that the strain had the strongest tolerance to Zn^(2+),followed by Cd^(2+),and Cu^(2+)was the worst. The enrichment of ions showed that biosorption amounts of Cu^(2+)and Zn^(2+)first increased and then decreased with time going on,the most adsorption capacity of Cu^(2+)was 6. 8 mg/g when the strain was cultured for 12 h,the most adsorption capacity of Zn^(2+)was 9. 0 mg/g when the strain was cultured for 12 h. The biosorption amount of Cd^(2+)increased with the time going on,the most adsorption capacity of Cd^(2+)was 8. 8 mg/g when the strain was cultured for 36 h. In summary,this strain had a great application prospect in bioremediation.