Primary processing and storage affect the dominant microbiota of fresh and chill-stored sea bass products

Abstract

The cultivable microbiota isolated from three sea bass products (whole, gutted, and filleted fish from the same batch) during chilled storage and the effect of primary processing on microbial communities in gutted and filleted fish were studied. Microbiological and sensory changes were also monitored. A total of 200 colonies were collected from TSA plates at the beginning and the end of fish shelf-life, differentiated by High Resolution Sequencing (HRM) and identified by sequencing analysis of the V3–V4 region of the 16S rRNA gene. Pseudomonas spp. followed by potential pathogenic bacteria were initially found, while Pseudomonas gessardii followed by other Pseudomonas or Shewanella species dominated at the end of fish shelf-life. P. gessardii was the most dominant phylotype in the whole sea bass, P. gessardii and S. baltica in gutted fish, while P. gessardii and P. fluorescens were the most dominant bacteria in sea bass fillets. To conclude, primary processing and storage affect microbial communities of gutted and filleted fish compared to the whole fish. HRM analysis can easily differentiate bacteria isolated from fish products and reveal the contamination due to handling and/or processing, and so help stakeholders to immediately tackle problems related with microbial quality or safety of fish.