Molecular analysis of the bacterial communities in the live Pacific oyster ( Crassostrea gigas ) and the influence of postharvest temperature on its structure

• Published in: Journal of Applied Microbiology
• Main Authors: Fernandez Piquer, J, Bowman, JP, Ross, T, Tamplin, ML
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Publishing Ltd 2012
• Subjects: Biological Sciences; Microbiology; Microbiology not elsewhere classified; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://doi.org/10.1111/j.1365-2672.2012.05287.x; http://www.ncbi.nlm.nih.gov/pubmed/22429335; http://ecite.utas.edu.au/77419

Aims: To evaluate the effect of postharvest temperature on bacterial communities in live Pacific oysters ( Crassostrea gigas ) using nonculture-based methods. Methods and Results: Live oysters were compared before and after storage at 4, 6, 15, 20 and 30 Celsius Degree using terminal restriction fragment length polymorphism (T-RFLP). Bacterial communities in freshly harvested (control) vs stored oysters were significantly different. Changes in bacterial communities at 4, 15 and 30 Celsius Degree observed by T-RFLP were further investigated by clone library analysis. Members of the Proteobacteria predominated (43.0-57.0% of clones) in control oysters, while storage altered the bacterial profile. At 4 Celsius Degree, Psychrilyobacter spp.(phylum Fusobacteria ) predominated (43.8% of clones), while at 15 and 30 Celsius Degree, members of the phylum Bacteroidetes represented 63.0 and 60.2% of clones, respectively. High microbial diversity in oysters was observed, with at least 73 different genera-related clones among all samples. Conclusions: Changes in the overall bacterial community of Pacific oysters were influenced by storage temperature and would likely not be detected by standard culture-based methods currently used to assess oyster quality. Certain dominant genera, such as Psychrilyobacter , Polynucleobacter and a bacterial group related to Alkaliflexus , should be further studied as possible indicators for postharvest temperature control. Significance and Impact of the Study: This work is the first report describing the effect of different storage temperatures on bacterial diversity in postharvest live Pacific oysters using molecular-based methods.