Received: Aug 21, 2018 / Accepted: Aug 21, 2018 / Published: Aug 21, 2018
In this study, experiments were performed to identify and screen Streptomyces strains that are antagonistic to Aeromonas hydrophila, which causes hemorrhagic disease in fishes. Among 80 isolates, 3 strains capable of antagonizing Aeromonas hydrophila by the agar diffusion plate method were obtained. The strain numbered 1083 had a strong activity with a 25 mm diameter clear zone of bacteria. This strain showed grey colonies after 7 days of incubation. After 7 days of incubation, the grey colonies had white borders, produced soluble pigments on the medium, grew well at 30°C and neutral pH, and adapted well to medium containing a high salt concentration. Strain 1083 was able to utilize different sources of carbon and nitrogen. Sequence analysis of 16S rRNA showed that strain 1083 had a similarity of 99% compared to Streptomyces antibioticus. Based on morphological, physiological, and biochemical characteristics, as well as molecular biological analysis, strain 1083 was identified as Streptomyces antibioticus.
