Abstract
Luminous bacteria were isolated from fish and shrimp culture waters in Japan and the Philippines. The viable counts of the water samples ranged from 101 to 106 cfu/ml and those of luminous bacteria ranged from 0 to 104 cfu/ml. A total of 63 luminous bacteria were selected from luminous colonies on agar plates and characterized alongside with Vibrio harveyi type strain based on morphological, biochemical and bacteriophage sensitivity tests. The luminous isolates were shown to belong to the genera Vibrio and Photobacterium based on their characteristics including flagellar arrangement, growth response to NaCl, glucose fermentation, oxidase production, and lysine and ornithine decarboxylase tests. Bacteriophage sensitivity test demonstrated that V. harveyi strains, including the type strain, were sensitive to two or more bacteriophages, while V. fischeri had no sensitivity to any of the bacteriophages tested. Seven isolates of V. harveyi from the Philippines were also confirmed to be sensitive to the bacteriophaes isolated in Japan.
