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

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.