Ecology Of Bacterial Physiological Groups Of Dajingshan Reservoir, Zhuhai

The population distribution of physiological groups of bacteria, including hetertrophic bacteria, nitrite fixer, nitrite reducer, ammonia oxidizer, nitrite oxidizer, inorganic phosphate bacteria, organic phosphate bacteria, aerobic cellulose decomposer, anaerobic cellulose decomposer, CMC-Na decomposing bacteria in the surface water and sediment of Dajingshan Reservoir were investigated by using MPN and flat count method from April 2005 to December 2005. Limiting factors of heterotrophic bacteria in the surface water were studied in Dajingshan Reservoir by pure cultural and natural cultural experiments.Main bacterial physiological groups in the surface water and sediment of Dajingshan Reservoir have a significant seasonal dynamics. In July, bacterial physiological groups were low, but abundant in Dcember, which was associated with temperature and nutrient concentrations. In Dajingshan Reservoir, water temperature was over 16℃ and nutrient concentrations were high in the winter, while the nutrient concentrations were low in the summer. As the input water of Dajingshan Reservoir was pumped from Qianshan River that was heavily polluted, bacterial physiological groups were relatively abundant in the surface water and sediment near the water input site. Physiological groups play an important role in the recycling of phosporus and nitrogen. 4 strains of phosphate bacteria were selected to study their ability in phosphorus release. Phosphate bacteria have strong ability to liberate phosporus. Inorganic phosphorus liberated by phosphate bacteria in cultrural medium was up to 51μg/L. Sediment is the center for nutrient recycle, And physiological groups in this site were 10～10⁵ times richer than of that in the surface water. There were signigicant correlations between bacterial physiological groups and environmental factors such as temperature, pH, PO₄-P, NO₃-N, NO₂-N and NH₄-N.Limiting factors of heterotrophic bacteria was studied by pure and natural cultural experiemnts. The result showed that growth factor and phosphorus were more important to bacterial growth than nitrogen and carbon. In addition, pH and high densities of planktons in the water body also affect the growth of heterotrophic...