Marine Pseudoalteromonas sp. Composes Most of the Bacterial Population Developed in Oysters (Tiostrea chilensis) Spoiled During Storage

ABSTRACT: To identify bacteria associated with spoilage in oysters, changes in both the load and composition of the bacterial community occurring in storage were followed. Oyster spoilage was accompanied by a 100-fold increase in the number of CFU. Molecular analysis revealed that a large proportion of the bacteria present in spoiled oysters possessed an intergenic 16S-23S rDNA spacer of approximately 400 bp. A spacer with the same size was also found in spoiled oysters of different origin and dates of harvest. The bacterial strains containing this spacer may constitute a common cause of the oyster spoilage. These strains were salt-dependent marine Pseudoalteromonas species and were probably present in oysters before harvest.