Abstract

• This research aims at assessing and determining the antimicrobial activity of Lactic acid bacteria (LAB) from the gut of Catla catla (Catla). Samples of fish were collected from fishery pond near Hinthada Township, Ayeyarwaddy Region. Isolation of LAB was undertaken by serial dilution method on deMan Rogosa Sharpe (MRS) medium, supplemented with 0.5% CaCO3. They were identified based on colony morphology, cell morphology, gram staining, acid fast staining, MR, VP, indole, catalase and motility tests. Total of five strains were isolated. Most isolated strains were gram positive, catalase negative and non- motile, and all were non-acid fast. Colony forming unit (CFU/mL) of isolated bacteria were counted by spread plate technique. CFU were ranging from 24x108 to 30x1010 CFU/mL. Isolated bacteria were also tested for antimicrobial activities using paper diffusion assay against Saccharomyces cerevisiae, Argobacterium tumefaciens, Pseudomonas fluorescens and Escherichia coli. The diameters of the inhibition zones were ranged from 8.4 to 14.7 mm. Out of five isolates, two strains (Cc1 and Cc2) showed antimicrobial activity against four test organism and inhibition zones were significantly higher (p< 0.05) than that of other isolates. These strains demonstrated high antimicrobial properties and could be used as starters for probiotic in fishery pond feeding.