Analysis of Enzyme Activities of the Gut Bacterial Communities in Labeo rohita fed Differentially Treated Animal Fleshing Diets

C Sumathi,D Mohana Priya

doi:10.4172/1948-5948.1000061

Abstract

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.

Highlights

The micro-environment of the digestive tract of fish confers a favorable growth for the microorganisms [1,2,3] by providing ecological niche for these organisms [4]
Proteolytic bacterial flora were found in all the experimental fish and the maximum count was observed in the gut of rohu (Labeo rohita) fed with fermented (27000 x103 CFU/g gut tissue) and microwave treated (24000 x103 CFU/g gut tissue) Animal Fleshing (ANFL) followed by raw, autoclaved > ozone > H2O2 treated ANFL
Protein is the dietary macronutrient and energy source whose requirement is prioritized in nutritional studies, either because it represents the highest fish feed cost, or greatly affects specific growth rate [78,80].Digestive enzyme activities of fish are associated with innate feeding habit and diet composition [81,82]

Summary

Introduction

The micro-environment of the digestive tract of fish confers a favorable growth for the microorganisms [1,2,3] by providing ecological niche for these organisms [4]. The microbiota of fish has been shown to be highly dependent on the bacterial colonization during early development, environmental conditions, nutrient composition and dietary changes [5,6,62]. These microorganisms grow upon the food absorbed by the host animal, digestive secretions and fragments scaled off the mucosal epithelium [7] and have a better chance of survival [8]. Preceding research suggests that digestive enzymes present in fish digestive tract can elucidate some aspects of their nutritive physiology [73] and be supportive to develop nutritional strategies for fish feeding and diet formulation [14,15,16,17]

Methods

Results

Conclusion