Abundance and Diversity of Nitrifying Microorganisms in Marine Recirculating Aquaculture Systems

Recirculating aquaculture systems (RAS) are important for water quality management in facilities, and can help resume consumption. However, information about the community structure of micro-ecosystem existing biofilters, especially participation known nitrifying groups (i.e., AOA, AOB, NOB, comammox Nitrospira), remains to be fully clarified. In this research, we compared structures three RAS operated at different temperatures a marine aquarium, through both amoA-targeted qPCR assay 16S rRNA-targeted next-generation sequencing. As result, AOA was primary nitrifier biofilters typically abundant diverse high-temperature samples (ca. 25 °C). NOB’s relative abundance patterns were numerically similar that suggesting cooperation relationship between NOB system. AOB comparable level with medium-temperature 19 °C), while their sharply decreased samples. The number observed OTUs 1.9 1.5 times as much detected low 10 °C) medium temperature respectively, more predominant occurrence high temperatures. Comammox Nitrospira only biofilter samples, negligible contribution nitrification process such ammonia-limited, saline biofilms. Although cannot by rRNA-based analysis, diversity indicated prospective possibility complete ammonia oxidation