CHARACTERIZATION AND ANTIBACTERIAL ABILITY OF THE Bacillus sp. STRAIN VNUA16 ISOLATED FROM FISH POND SLUDGE IN HAI PHONG

Abstract

Aquaculture industry, which plays an important role in Vietnam economy, has been oriented for effective and sustainable development. However, aquaculture is facing with the appearance of more serious water pollution and aquatic animal diseases. Bacillus species are capable of synthesizing antibacterial substances and degrading organic compounds, contributing to the control of aquatic diseases and improve water quality. Therefore, the study was carried out to determine biological characteristics and antibacterial ability of the VNUA16 strain isolated from fish pond sludge in Hai Phong  province. The study of morphological, biochemical characteristics and 16S rRNA gene sequence showed that the strain VNUA16 belongs to the genus Bacillus. The antagonistic activity of this strain was evaluated by the diffusion plate method.  According to the results, the Bacillus sp. strain VNUA16 was able to antagonize Vibrio parahaemolyticus, Pseudomonas aeruginosa P2.1 and Staphylococcus aureus SA12, recording inhibition zones of 6.43; 8.53; 9.57 mm, respectively. At pH6 and 30^oC, this strain exhibited the strongest antibacterial activity against Pseudomonas aeruginosa P2.1. The strain Bacillus sp. VNUA16 has a promising potential to be used as a biological agent for control of aquatic animal diseases.