Study on microbial diversity of biofloc system

Ammonia nitrogen control is very important in intensive aquaculture. The present study evaluated different management strategies i. e. chemoautotrophic, heterotrophic with glucose or polyhydroxy butyrate- hydroxy valerate (PHBV) added as carbon sources, and a mature biofloc system on the water quality and microbial community in the system. In the domestication stage, the average NO2--N concentration, pH and DO in the glucose adding group were significantly lower than those in the control and PHBV adding groups. The genus Nitrosospira and Nitrosomonas were the main ammonia oxidation bacteria detected, and Nitrospira was the only genus of nitrite oxidation bacteria detected. Carbon sources addition decreased both the bacteria richness and diversity in the fish culture stage.