Characterization of Bacilli Isolated from the Gut of Rohu, Labeo rohita, Fingerlings and Its Significance in Digestion

Abstract Three types of intestinal bacteria (Lr 1.1, Lr 1.2, and Lr 2.2) were isolated from the gut of rohu, Labeo rohita, fingerlings. Pure cultures of the bacteria were grown on Tryptone Soya Agar (TSA) plates and were identified as Bacillus circulans, B. pumilus, and B. cereus through morphological, physiological and biochemical tests. The extracellular protease, amylase, and cellulase producing capacity of the isolated organisms were detected in in vitro culture. Biochemical characterization of the isolates suggests that the microorganisms (Bacillus circulans, B. pumilus, and B. cereus) might play an important role in the nutrition of rohu fingerlings. The results of the study will be helpful in formulation of practical diets incorporating non-conventional ingredients.