Pavlova I. Morphophysiological properties of purple sulfur bacteria genus Thiocystis and Chromatium isolated from reservoirs that are enriched with hydrogen sulfide

The thesis is devoted to study of purple sulfur bacteria genus Thiocystis and Chromatium, their morphophysiological and biochemical properties, their ability to use hydrogen sulfide in process of anoxygenic photosynthesis, optimization of cultivation conditions and H2S utilization by purple sulfur bacteria. The pure cultures of purple sulfur bacteria were isolated. Isolated strains were identified to genus Thiocystis and Chromatium. Optimal conditions for bacteria growth were established. The qualitative and quantitative pigment compositions of isolated strains were investigated. The main factors that have an influence on pigment composition were established. It is established that isolated strains are resisting to high concentration of hydrogen sulfide in the medium. The most effective process of hydrogen sulfide utilization occurred at concentration of 200 mg/l and light intensity 1000 lx. On the basis of the multifactorial analysis the nutrient medium was created. This medium has allowed to increasean output of Thiocystis sp. Ya2006 biomass and to accelerate hydrogen sulfide detoxication.