PHENOTYPIC CHARACTERIZATION AND MOLECULAR IDENTIFICATION OF A LUMINESCENT MARINE BACTERUM ISOLATED FROM THE NW SHELF OF CUBA

Light emitted by luminescent bacteria is sensitive to several toxic compounds; therefore, some luminous species have been used to evaluate the quality of water environments. In the present study we carried out the phenotypic characterization and molecular identification of a marine luminescent isolate (CBM-784) from the NW Cuban coast. The identification of the CBM-784 luminous isolate was based on phenotypic and genotypic characteristics. Phenotypically, the CBM-784 strain revealed the following characteristics: Gram negative, positive to oxidase and catalase reactions, bioluminescent, and facultative anaerobic respiration. The bacterial strain produces enzymes with gelatinase, lysine carboxylase and amylase activity. Taken together, these assays indicated that CBM-784 showed a high phenotypic similarity to the Vibrio harveyi ATCC 14126 strain. On the basis of 16S rRNA gene sequencing, CBM-784 was closely related to Vibrio harveyi and Vibrio rotiferianus (94% similarity). Sequence analysis of gyrB gene, has shown that CBM-784 shares taxonomic position with Vibrio campbellii and Vibrio harveyi isolates, with 95% of bootstrap value. In addition, sequence analysis of pyrH gene, grouped this isolate to the Vibrio harveyi cluster with a strong bootstrap support (99%). The multilocus sequence analysis and phenotypic characterization of CBM-784 indicated that this strain have a strong relation to Vibrio harveyi.