一株富含类胡萝卜素光合细菌菌株GP-7的分离鉴定

从珠海横琴岛近海海水中筛选到一株光合细菌GP-7,测定了其类胡萝卜素含量,通过形态观察及16S rRNA编码序列同源性比较分析确认其种属,并对该菌的生长条件和生物学特征进行了初步的研究。结果表明：GP-7的类胡萝卜素质量分数为4.87 mg/g（干菌体）,该菌符合光合细菌的生物学特征,其最适pH为7.0,盐度为1.0%;16S rRNA基因分子系统学分析表明,该菌株与紫色非硫菌（Rhodoplanes）相似性为99.5%。

Isolation and identification of a strain of photosynthetic bacteria GP-7 with high-yield production of carotenoid pigments

A strain photosynthetic bacteria GP7 was isolated from sea water of Hengqin island,Zhuhai city.The contents of carotenoid pigments in dry cells were measured,the growth condition and biological characters were studied basically.Results showed that the maximum production of carotenoids pigments for GP-7 was 4.87 mg/g dry cells and it accorded with the biological characters of photosynthetic bacteria.The optimum pH of GP-7 was 7.0 and the optimum salinity was 1%.Based on 16S rRNA sequences,a sequence similarity between GP-7 and Rhodoplanes was 99.5%.