The Study On Isolation, Identification Of The Purple Non-Sulfur Bacteria And It's Application In Organic Wastewater With High Concentration

Utilization of the photosynthetic bacteria (PSB) in wastewater treatment is a new technology that has been developed in recent years. This method has some unique advantages, but as a new technology, it also has some defects, one of which is that too much CODcr remained, The wastewater treated by PSB must be retreated by the activated-sludge reactor. In order to improve the treatment efficiency of PSB, a strain of purple non-sulfur bacteria with high capacity of degradation was isolated and screened from nature, At the same time, the mixed-culture technology was employed to study the treatment efficiency of soybean wastewater using pure PSB, mixed PSB and the mixed cultures of the PSB and Sacchromyces.cerevisiae respectively. In addition, the biological factors that influenced treatment efficiency of PSB were also investigated.The main results were described as follows:(1) Cells of the strain YT0813 isolated from nature was gram-negative, facultatively aerobic, and was motile by means of a single flagellum .After 18h of culture, the cells slightly rod-shaped, 0.75 to 1.2um wide, 2.5um long. Under anaerobic conditions in the light, the cultures appears purplish red and ultrathin sections of photosynthetically growing cells revealed the presence of lamellar intracytoplasmic membrane(ICM)systems. The lamellae formed were extended parallel to the cytoplasmic membrane and in the form of stacks. Strain. YT0813 can utilize various organic compounds as carbon sources, eg acetate, propionate and butyrate, but cannot utilize sugar et al. According to the Sergey's Manual of Determinative Bacteriology, 8th ed. Strain YT 0813 was proposed for Rhodoseudomonas.palustris(2) The study on soybean wastewater treatment by PSB showed that under microaerobic conditions, the mixed purple non-sulfur bacteria have a high CODcr removal rate of 73.5%, while using strain YT0813, the rate was only 50.2%.(3) The study on soybean wastewater treatment by combined bacterium showed thatthe CODcr removal rate of the combined bacterium A, which were composed of strainYT0813 and Sacchromyces.cerevisiae, was only 53.17%. However the CODcr removal rate of the combined bacterium B, which were composed of mixed purple non-sulfur bacteria and Sacchcromyces.cerevisiae, could reach 87.3%. The difference was obvious.