Abstract

BACTERIOLOGICAL ANALYSIS IN THE GUT OF Cirrhinus cirrhosus AND SCREENING THE EFFECT OF BACTERIOCIN AGAINST COMMON GRAM-NEGATIVE BACTERIAL PATHOGENS

Karuppasamy Murugan*

Abstract

In the present study focuses, Cirrhinus cirrhosus (mrigal fish) was collected from the freshwater fish cultivation pond and the total heterotrophic bacterial population (THBP), the total lactic acid bacterial density and the amylase, protease and cellulase producing bacterial load in the gastro-intestinal tract were enumerated. In this study quantitative wise, amylase and protease producers were found to be in the first two positions and the last position was acquired by cellulase producing bacteria were also determined. Using selective media, common pathogens and beneficial bacteria were isolated for this study. A total of 10 bacterial isolates were selected and taken for identification up to generic level by morphological and biochemical aspects. Aeromonas sp., Vibrio sp., Pseudomonas sp., Salmonella sp. and Lactobacillus sp. were the identified pathogenic and beneficial bacteria. From this study, the probiotic role of Lactobacillus sp. was checked through cross streaking technique and the presence of antagonistic activity in Lactobacillus sp. against the Aeromonas sp. was confirmed. Production of bacteriocin in the two Lactobacillus sp. isolates was noted and the bacteriocin was found to be effective at pH 8 but not at pH 7 was determined. Finally I concluded from this study, revealed the possibility of using bacteriocin as a food preservative and the Lactobacillus sp. as a probiotic and antibiotic resistance studies revealed the emergence of resistance invariably in all the studied bacterial pathogens against the tested antibiotics and the need for the inclusion of sustainable friendly techniques such as probiotics, immunostimulatns etc. for managing fish health and diseases.

Keywords: Mrigal fish, Lactic acid bacteria, Nutrient agar medium, Bacteriocin, Probiotics and Antibiotics.