Effects of Soybean Meal Incorporated Diet on Enzyme Producing Autochthonous Gut Bacteria in Fingerlings of Labeo Rohita (Hamilton)

- Gut microbiota have important role in the digestive process of fish. Soybean meal based diet effects on gut microbiota of Labeo rohita by altering enzymatic activities like amylase, protease and cellulase. Two diets were prepared, one using fish meal and the other using soybean meal as the major protein source. The feeding trial was conducted in 90L circular flow-through fibre-glass tanks for 90 days under laboratory condition. After ninety days of feeding trial fish weight gain percentage, SGR FCR, PER was better with soybean meal diet in comparison to the fish meal diet. Amylase, cellulase and protease producing aerobic bacterial count were increased in both the proximal intestine (PI) and distal intestine (DI). The isolated strains from the PI and DI of the test fish were screened by qualitative enzyme test. The specific amylase, cellulase and protease activity before and after feeding trial were recorded. A distinct change in the quantitative enzyme activities in the bacterial strains were noticed after feeding with soybean meal diets which indicated that soybean meal can influence the autochthonous enzyme-producing microbial community in the GI tract of fish.