Functional genes distribution pattern in different positions of bio-filter in recirculating systems culturing Oncorhynchus mykiss

The community structure of ammonia oxidation bacteria (AOB), nitrite oxidation bacteria (NOB) and denitrification bacteria were investigated in different positions of the biofilter in a recirculating aquaculture systems (RAS) using function genes analysis. Results showed the water quality in the front (BFF), middle (BFM) and back (BFB) of the biofilter was different