Dynamics of bacterioplankton in water bodies contaminated with nitrogen

There have been presented the results of the microbiological research for 2003-2005 into the cascade of ponds in the dendropark Aleksandriya (the town of Belaya Tserkov). The water of thereof had concentration of mineral nitrogen typical of hypertrophic water bodies (69.9-413.9 mg N/l). The amount of oxygen dissolved in the water was equal to 48.5-7.2%. The number and biomass of the bacterioplankton in ponds varied from 3.4 to 23.2 × 106/cells ml-1, from 64.6 to 412.4 μg C/l-1 respectively. During the whole period of the observation rod-shaped bacteria prevailed in the number and biomass of the bacterioplankton (68.0-85.0% and 62.8-77.1% accordingly); coccal forms reached 9.7-22.1% of the total number and 12.7-28.0% of the biomass of bacteria; curve-shaped bacteria - 0.9-18.9% and 1.9-23.3% respectively. The average volumes of rod-shaped bacteria amounted to 0.054 μm3, cocci - 0.074 μm3, curve-shaped cells to 0.191 μm3. In the most contaminated pond where ammonia nitrogen reduced, the volumes of cells, number and biomass of bacterioplankton rose, which indicated active processes of assimilation N-NH4 by bacteria using it to synthesize amino acids.