[Effect of Water Bloom on the Nitrogen Transformation and the Relevant Bacteria].

The biogeochemical cycle of nitrogen in the aquatic environment is the research hotspot in the world all the time. Nitrification and denitrification are the special processes of the microorganisms, and also the key steps in the nitrogen biogeochemical cycle possessing great significance in the freshwater ecosystem. In the processes of outbreaks of cyanobacterial blooms, total nitrogen, chlorophyll a, dissolved oxygen and pH decreased sharply, whilst dissolved organic carbon and ammonium nitrogen increased. The results of simulation of outbreaks of cyanobacterial blooms using micro-universe system in lab showed that the amoA gene abundance was reduced in the early stage and AOA was replaced by AOB gradually. Our results also showed that the amount of denitrifiers with nirS/nirK was elevated by also 100 times during the bloom outbreak, which can explain the promoted denitrification in the water during cyanobacterial bloom.