author(s)
Dipika Doloi and Dip Jyoti Haloi

abstract
Microbial isolation from the gastro-intestinal tracts (only the midgut and hindgut) of Channa punctata have been performed to detect their importance in the digestion process of the experimental fish. Three types of microbes (bacteria and fungi) were separated from the GI tract of Channa punctata. Pure bacterial cultures were grown on Nutrient Agar (NA) media and were identified as Gram –ve cocci shaped bacteria through morphological test. While pure cultures of fungi were grown on Potato Dextrose Agar (PDA) media and were identified as Penicillium sp. and white sterile mycelia with no spore formation through morphological test. Intestinal isolates were checked for extra-cellular enzyme producing abilities by plate screening method. Amylolytic and cellulolytic microbes were found in the experimental fish’s gut. Cellulase activity was shown by all microbial isolates, while amylase activity was exhibited by the bacterial isolates and Penicillium sp. isolated from the GI tract of Channa punctata. Thus, from the experimented study, it can be concluded that, there would be a possibility of the digestive enzymes to be supplemented by the microbes of the experimental fish’s gut, which would be helpful in the preparation of diets, constituting or including the feeds that are non-conventional ones. Moreover, the microbes of the fish gut may help in the digestion process of the fish, and this study have isolated and identified the enzyme‐producing microbes.