Pyrosequencing of bacterial 16S rRNA was undertaken to assess diversity in microbial communities of Pacific and Sydney rock oysters during storage. Pyrosequencing yielded 112,624 sequences (after quality trimming) from the 18 oyster samples analysed. The minimum sequence reads per sample was 1325, the maximum was 17,355 and the mean number of reads was 6256.
At the phyla level (Fig. 4), the bacterial profile of fresh Pacific oysters was dominated by Proteobacteria (58%) and Tenericutes (42%). The initial profile of fresh Sydney rock oysters was similar to Pacific oysters, although Proteobacteria (14%) represented a smaller proportion of the profile with increased abundance of Tenericutes (53%) and Spirochetes (27%). However, by Day 7 the microbial profiles of spoiled Pacific and Sydney rock oysters were nearly exclusively dominated by Proteobacteria (95% and 99% respectively).