Characterization of microbial community in high-pressure treated oysters by high-throughput sequencing technology

High-pressure (HP) processing technology has great application potential in bivalve mollusk industry. In this study, the effects of HP treatment on shucking and shelf-life extension of Pacific oysters (Crassostrea gigas) during 4 +/- 1 degrees C storage were studied. Culture-independent high-throughput sequencing (HTS) technology was used to investigate the microbiota of oysters treated by HP (300 MPa, 2 min) during storage. Results showed that HP treatment at 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle, pressures higher than 300 MPa caused disadvantageous damage of shells. Therefore, HP treatment at 300 MPa for 2 min was particularly appropriate. Based on organoleptic, biochemical and microbiological analyses, shelf life of 6-8 days for control and 12 days for HP-treated oysters could be expected. The dominant bacteria in fresh oysters were Vibrio (28.3%), Shewanella (10.3%) and Pseudoalteromonas (7.2%). HP treatment changed the spoilage microbiota of oysters dramatically. Psychrobacter was dominant in the HP-treated spoiled oysters and its proportion was 42.3%, while Pseudoalteromonas (32.2%) and Shewanella (19.5%) were dominant in the spoiled oysters without HP treatment. This study confirmed that HP processing was effective in facilitating the removal of oyster meats from the shells and prolonging their shelf-life. More importantly, HP treatment changed the microbiota of oysters during chilled storage. Industrial relevance: As seafood, oysters have a short shelf-life. High-pressure (HP) processing technology has showed great application potentials in the bivalve mollusk industry. In this work, we determined the effects of HP treatment on the shucking and shelf-life extension of oysters. We used high-throughput sequencing technology to investigate the microbiota of control and HP-treated oysters during refrigerated storage. We found that HP treatment changed the spoilage microbiota of oysters dramatically. Psychrobacter was dominant in the HP treated spoiled oysters, while Pseudoalteromonas and Shewanella were dominant in the spoiled oysters without HP treatment. Therefore, controlling the growth of Psychrobacter could help to improve the quality of oysters treated by HP during storage.