<i>Shewanella oncorhynchi</i> isolated from a recirculatory aquaculture system (RAS) in Alberta, Canada

Certain <i>Shewanella</i> spp. cause spoilage of seafood. However, <i>Shewanella</i> from fish production facilities in Canada have not yet been characterized. In our study, we first isolated <i>Shewanella oncorhynchi</i> S23-S33 (S2-3) from the water in a rainbow trout tank from a recirculating aquaculture system (RAS) facility located in Alberta, Canada. Later we found another strain (FD-1) from the biofilters from the same facility. Whole genome sequencing revealed that both strains possess gene clusters for the biosynthesis of eicosapentaenoic acid and we confirmed the production in FD-1 by gas chromatography. Phylogenetic analyses showed the close relatedness of FD-1 and S2-3 to <i>S. oncorhynchi</i> S-1. Rainbow trout filets inoculated with FD-1 turned brown in colour compared to uninoculated. However, when we inoculated retail pink salmon (<i>Oncorhynchus gorbuscha</i>) with either FD-1 or S2-3, we did not observe the brown colour change. The storage time had a significant (<i>P</i> < 0.0001) impact on the lightness (L^*), red/green (a^*), and yellow/blue (b^*) of pink salmon. In summary, our research note records the preliminary characterization of <i>Shewanella</i> from a RAS trout facility in Alberta, Canada.