Effect of biochemical characteristics and environmental factor of water purification photosynthetic bacteria PS2 on its growth

Nonsulfuric purple bacteria PS2 is a strain isolated from sediment of shrimp aquaculture ponds.Based on morphological,physiological and biochemical experiments,it was identified to be Rhodopseudomonas capsulate.The strain can effectively utilize broad categories of substrates including most small molecules such as organic acids, sugars and alcohols,and thus has great potential in purifying aquaculture waters.Influences of environmental factors on growth of the strain were studied using light absorption method. Results showed that the strain can grow under 20-40℃,salinity of 0-40.0 and pH 6.0-9.0,with optimum of 30℃, 10 and pH 7.0. Its growth rate increases with light intensity, under illumination of 500-5000lx. The strain can grow both anaerobically in dark and aerobically in light.The environment conditions in aquaculture ponds are favorable for growth of the strain, and the optimal growth conditions obtained from this study can be used for large-scale bacteria production.