Antimicrobial Activity of Heterotrophic Bacterial Strains of Marine Origin

Background: Bacterium-bacterium antagonistic interactions could be important in the ecology of marine bacteria. Antimicrobial properties of microorganisms are exploited in various fields of human activities. Objectives: Antagonism of heterotrophic bacteria from different marine environments of tropical and temperate zones was examined. Materials and Methods: Bacteria were isolated from biofilm samples, tissues of hydrobionts and sea water. Isolates were characterized by phenotypic and 16S rRNA phylogenetic analyses. Agar diffusion assay was applied to investigate inhibitory interactions. 5 type strains and 21 strains of marine origin were used as test cultures. Results: 68.97% of isolates from temperate zone and 56.76% of tropical zone showed antimicrobial activity. The most active strains belonged to genera Pseudomonas and Pseudoalteromonas. Conclusions: Bacterial interspecies growth inhibition is widely distributed in marine environments. Marine bacteria, especially Vibrio spp., may be good probiotics which are active against pathogenic bacteria.