Heterotrophic Bacterial Community Structure of Multistage Biofilters in a Commercial Pufferfish Takifugu rubripes RAS

摘要

The success of a recirculating aquaculture system (RAS) greatly depends on the structure, dynamics and activities of microbial community. Heterotrophic bacteria as the major members play various roles. The heterotrophic bacterial community structure in three-staged biofilters was studied using four different media. 228 isolates belonging to 77 species were obtained and affiliated to Gammaproteobacteria, Alphaproteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Betaproteobacteria. Gammaproteobacteria was the predominant group. The concurrence was found between potential pathogens {Vibrio and Shewanella) and probiotics (Bacillus and Pseudomonas). On the basis of community diversity index, we could infer that differences existed between stages, and the diversity index increased along the biofilters. A comprehensive understanding of microbial community in RAS will be in favor of utilization of microbial resources and optimizing the culture systems' operation.