C. Sumathi, D. Mohana Priya, V. Dilli Babu and G. Sekaran
The present investigation includes isolation, enumeration and comparison of the gut microbial flora of Labeo rohita fed differentially treated Animal Fleshing (ANFL) as a sole protein source in their diets and related increase in enzyme secretion. ANFL is the proteinaceous tannery solid waste generated during leather processing and inclusion of ANFL in aqua feed will pave way for the novel alternative cheaper protein source in replacement of fish meal. Six experimental diets were formulated with differentially processed ANFL. The isolates from the gut extract were qualitatively screened and quantitatively assayed for amylase, cellulase, lipase and protease activities. The total culturable bacterial count (10 × 10 7 CFU/g) as well as the proteolytic bacterial count (27 × 10 6 CFU/g) was high in the fish gut fed with diet 5 containing the fermented ANFL. Almost all the bacterial isolates possesses protease activity in which strains (FF5, CF3and CF4) isolated from the diet 5 (287U) and 7 (282U) exhibited highest activities. Maximum cellulase (FF2), amylase and lipase (RF6) activity were observed in the strains isolated from the diets 5 and 1 (78U, 186U and 97U). This study proves the existence of diet dependent enzyme producing bacterial community in the gut of Labeo rohita through SEM analysis and the information generated from the present study might contribute towards utilization of enzyme producing bacterial isolates as probiotic and in better feed formulations at low cost for rohu incorporating the tannery solid waste ANFL as a protein source.