一株嗜酸硫氧化细菌的分离鉴定及生长特性

从北京清河污泥中分离出一株硫氧化细菌,命名为QH-1,并对该菌株进行了分离鉴定.同时,初步研究了该菌株对几种重金属离子的耐受能力.结果发现,该菌株为革兰氏阴性,短杆状,需氧型,可从氧化还原态的硫元素中获得能量.QH-1菌株具有很好的产酸和耐酸能力,培养24h后pH即可下降到2.0,1周内可达到1.0以下,对数生长期为15d,进入稳定期时pH降为0.6.QH-1菌株的16S rRNA基因测序与分析表明,该菌株与Acidithiobacillus thiooxidans strain AAU具有99%以上的16S rRNA基因序列相似性.通过构建该菌株在相关种属中的系统发育树,并结合形态与生理生化特征分析,将QH-1菌株鉴定为氧化硫嗜酸硫杆菌(Acidithiobacillus thiooxidans).QH-1菌株对Zn2+和Cu2+有一定的耐受性,对Mo2+的耐受性较差.

The isolation,identification and characteristics of a sulfur-oxidizing bacterium,Acidithiobacillus thiooxidans

Acidithiobacillus thiooxidans QH-1 was isolated and purified from sludge which was collected from the Qinghe River in Beijing. A preliminary study of the strain's tolerance to several heavy metal ions was made. QH-1 was a Gram-negative, short rod, facultative aerobe. The strain could oxidize reduced sulfur compounds to obtain energy. The strain had a high acid production capacity, was resistant to acid, and showed a long logarithmic growth phase of probably 15 days. The strain grew well in a pH environment between 6.0 and 0.6 and could survive in a low pH environment. Using the 16S rRNA sequence and homology analysis, a phylogenetic tree of the strain with related species was constructed. The results showed that QH-1 is a strain of Acidithiobacillus thiooxidans. QH-1 has a high tolerance to Zn2+ and Cu2+ and a poor tolerance to Mo2+.