An investigation on the intestinal bacterial flora of cultured rainbow trout (Oncorhynchus mykiss)

Objective: The use of probiotic organisms to modify the fish gut microflora is considered as a popular topic for investigation. Probiotics are harmless bacteria that help the well being of the host animal and contribute, directly or indirectly to protect the host animal against harmful bacterial pathogens. Normal microflora of fish gut has an inseparable function in relation to probiotics. Method & Materials: In order to know intestinal bacterial flora which inhabit as normal flora of healthy rainbow trout gut for production of proficient probiotics, 12 rainbow trouts with average weight of 45 g were sampled from one of fish farms of Fars Province. Immediately after euthanizing, the fish were dissected and intestinal mucosal was inoculated on common and specific bacteriological media. Results & Conclusion: After isolation of bacteria and performing of biochemical tests, Aeromonas hydrophila was isolated from 10 fish, Pseudomonas fluorescens was isolated from 6 fish, Proteus rettgeritrom was isolated from 4 fish, Acinetobacter caicoafeticus was isolated from 4 fish, Flavobacterium sp. was isolated from 1 fish, Arthrobacter crystallopoietel was isolated from 1 fish and Carnobacterium sp. was isolated from 1 fish

Keywords:

normal bacterial flora , rainbow trout , probiotics