• K. Sivagami
• J. Ronald

Present study was aimed at isolation, selection, and identification and counting of bacteria from the gastrointestinal tract of Indian major carp, Cirrhinus mrigala fed with probiotic yeast (Saccharomyces cerevisiae) supplementary test diets. The gastrointestinal tract of fish is an important ecosystem possessing a specific microbiota. The gut is the major organ where probiotics establish and execute their functions. The continuous application of living yeast may lead to high level of colonization and modulated gastro intestinal microbial population. On the basis of morphological characteristics, gram staining reaction, bio chemical test and sugar utilization, seven species of bacteria were isolated and identified from both the proximal and distal intestine and screened. The identified species were E.coli, Bacillus staphylococcus, Lactobacillus, Micrococcus, Lactococcus and Enterobacteria. The results have revealed that occurrence of gram negative bacteria was around 75% and of gram positive was 25%. Amongst the isolates, heterotrophic bacteria were maintained in nutrient agar stand at 4oC. These bacteria were mass cultured and the total bacterial count was found. The highest level of yeast supplementation significantly increased in the relative occurrence of bacterial population. The total bacterial count was maximum when compared to that of control. These results clearly indicate that yeast supplementation affected the diversity and composition of gut microbiota in Cirrhinus mrigala and increased the relative abundance of potential beneficial bacterial species. The results indicate that there is ample scope for further research to appraise fish gut microorganisms to improve feed efficiency in fish.

Fish gut bacteria, Indian major carp, Probiotics, Saccharomyces cerevisiae

"EVALUATION OF GUT BACTERIAL POPULATION IN Cirrhinus mrigala FED WITH PROBIOTIC YEAST FEED", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.9, Issue 4, page no.b552-b571, April-2022, Available :http://www.jetir.org/papers/JETIR2204172.pdf

"EVALUATION OF GUT BACTERIAL POPULATION IN Cirrhinus mrigala FED WITH PROBIOTIC YEAST FEED", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.9, Issue 4, page no. ppb552-b571, April-2022, Available at : http://www.jetir.org/papers/JETIR2204172.pdf