一株极端环境光合细菌的生理特性研究

THE ISOLATION AND CHARACTERIZATION OF HALORHODOSPIRA SP., A HALOPHILC AND ALKALIPHILC PHOTOSYNTHETIC BACTERIUM

  • 摘要: 从山西运城盐厂解化池分离获得一株嗜盐嗜碱细菌,编号为Y。其纯培养物经形态学、生理生化特性和DNA G+C含量等特征分析,结果表明,该菌株可在盐度ρ(NaCl)/gL-1为160和pH9.0碱性条件下生长。单细胞为杆状,大小为0.4-0.8×0.9-1.5μm。二分裂繁殖。革兰氏阴性。光合内膜为片层堆积并与细胞质膜相连,但并不与细胞质膜平行。细胞含有细菌叶绿素a,液体培养物呈玫瑰红色。Y菌株不仅可将硫化物氧化为元素硫沉积于细胞外,也可光同化多种有机物,并具有固氮和产H2特性。DNA中 G+C含量为61.6%。根据以上鉴定特征及相关资料,Y菌株应归于嗜盐红螺菌属(Halorhodospira)。但其生长所依赖的盐度、pH、细胞内色素成分及鞭毛着生方式与该属正式承认的3个种有明显的不同。该菌株独特的生理生化特性,对于极端环境微生物的资源开发和利用有重要的理论意义和应用价值。

     

    Abstract: Strain Y has been screened from salt flats of Yuncheng Saline lant in Shanxi Province. According to the 《Bergey's Manual of Determinative Bacteriology》ninth edition(1994), 《Bergey's Manual of Systematic Bacteriology》third volume)1989)and some related materials, the pure culture the morphological, salinity test, physiological and biochemical properties, should be classified into the genus Halorhodospira. Growth of strain Y was depended on 16 percent sodium chloride and pH 9.0 alkaline condition. Cell was rod shaped, 0.4-0.5μm wide and 0.9-1.5μm long. Photo-synthetic pigment is bacteriochlorophylla a. Color of cell suspensions is rose red under anaerobically with incandescent lamp. Multiplication is by binary fission. Internal photosynthetic membranes are present as lamellar stacks that are continuous with the cytoplasmic membrane. Under anaerobic condition, it is capable of growing photoautotrophically with reduced sulfur compounds as sole electron donors, sulfide is oxidized to element sulfur, which is deposited outside the cells, and may be further oxidized to sulfate. It is also able to grow photoheterotrophically with many simple organic compounds . On the basis of its optimum NaCl requirements, pH, photosysthetic pigment and the mode of flagellum, the strain is significantly different from all known species of Halorhodospira, this strain's taxonomic status will further be discussed.

     

/

返回文章
返回