Abstract
DNA regions corresponding to portions of two different pressure-regulated operons previously identified in two deepsea barophilic bacteria were separately PCR amplified from a variety of deep-sea microorganisms and sequenced. With the two sets of primers employed, amplification was particularly successful from the more barophilic bacteria examined. 16S rRNA sequence analysis revealed that these bacteria are all phylogenetically related and belong in a sub-branch of the genus Shewanella containing only the deep-sea Shewanella barophilic bacteria, which we define as the "Shewanella barophiles branch" containing at least two different species. Our results suggest that the DNA sequences of the pressure-regulated operons can be considered as marker sequences to identify the Shewanella barophilic strains.
