产生辅酶Q_(10)的光合细菌菌株的分离及鉴定

Isolation and identification of a photosynthetic bacteria producing coenzyme Q_(10)

对水塘污泥中富集分离的13株光合细菌产生的CoQ10进行定性定量分析,筛出CoQ10含量较高的菌株2c并对其进行系统鉴定。菌株2c为革兰氏阴性菌,细胞杆状,菌体大小0.6μm^0.9μm×1.2μm^2.0μm,单极生鞭毛,片层状光合内膜,位于细胞质膜下并与之平行。光照厌氧或黑暗好氧条件下均可生长,光照下菌体产生红色素,菌体含有细菌叶绿素a和类胡萝卜素。最适生长温度30~35℃,pH7.0~8.0。多种有机化合物均可作为光合作用的电子供体和碳源,蛋白胨和硫酸铵是其生长的较好氮源,酵母膏对其生长有明显刺激作用。16S rDNA序列系统发育分析表明,菌株2c在系统进化树上与GenBank中序列号为AY751758、DQ001155、DQ001158的沼泽红假单胞菌聚为一族。菌株2c至少能稳定传代15次。初步确定菌株2c为沼泽红假单胞菌。

13 isolates producing Coenzyme Q10 （CoQ10） of purple non sulfur photosynthetic bacteria were enriched out of pond sludge,one isolate named 2c was selected based on its high CoQl0content and identified systematically. The gramnegative and short-rod shaped strain 2c is 0.6μm - 0.9μm × 1.2μm - 2.0μm, has one long flagellum on one end of the cell and contains lamellar intracytoplasmic membrane（ICM） system parallel to cytoplasmic membrane. Cultures produce red pigments in the light. Live cells under phototrophic conditions contain bacteriochlorophyll a and carotenoids. 2c grows anaerobically in the light and aerobically in the dark. Optimal growth occurs at 30℃-35 ℃ and at pH7.0 - pH8.0.Various organic compounds are used as photosynthetic electron donors and carbon sources. Peptone and （NH4）2 SO4 are its better nitride source,yeast extracts stimulates its growth. A phylogenetic analysis based on 16S rDNA gene sequences reveales that strain 2c gathers a cluster with 3 strains of Rhodopseudomonas palustris whose accession number in GenBank are AY751758, DQ001155, DQ001158, respectively. 2c subcultures 15 generations stably at least. The results presented here demonstrated strain 2c is Rhodopseudomonas palustris.