Abstract
Eighty-five strains of marine bacteria were isolated from the Muroto deep seawater at a depth of 320m off the coast of Cape Muroto, Kochi Prefecture, Japan. The bacteria were analyzed based on the sequences of the 16S rRNA gene. Seventy-five strains were identified as 12 genera; 29 strains to the genus of Vibrio, 16 to Pseudoalteromonas, 9 to Shewanella, 6 to Alteromonas, 4 to Marinobacter, 3 to Erythrobacter, 2 to Tenacibaculum, 2 to Dietzia and 1 strain each to the genera of Bacillus, Halomonas, Idiomarina and Photobacterium. Some of these strains were closely related to known bacteria including psychrotrophs, barophilic bacteria and bacteria which decompose hydrocarbons. Some other strains produced pigments reported to have physiological activities. On the other hand, the remaining 10 unidentified strains contained novel bacteria whose DNA sequences showed low homology with those of the already identified bacteria. Thus, the Muroto deep seawater has been demonstrated to be an important source for investigations of unknown, yet potentially useful, bacteria.
