The role of probiotics in the control of bacterial diseases and biodegradation of organic matter in shrimp (Penaeus vannamei) culture ponds of South India

Objective: To utilize bacterial consortium as probiotics for the biodegradation of organic matter and to control the emergence of bacterial disease in shrimp culture pond. Methods: Water samples were collected from shrimp culture ponds of Southern India. The physico-chemical properties of the water viz., pH, temperature and colour were analyzed. The bacteria were isolated and were screened for different enzyme assays. The bacterial isolates named MSWS24, MSWS30, and MSWS19 were identified and were optimized at different physical parameters for the maximum enzyme production. The treatment of bacterial pathogen using bacterial consortium was tested to analyze the degradation. Then the water quality at four different setups were analyzed and the amount of organic load was accumulated. Finally the survival rate of the shrimp was observed and total shrimp yield was examined. Results: In this study the cell suspensions of Bacillus subtilis, Bacillus licheniformis, Bacillus firmus strains, were isolated from shrimp pond water, taken in equal proportions and administered as probiotic in Penaeus vannamei culture. The optimization of enzyme activity of the three isolates showed a particular parameter with high productivity. When compared to the untreated control group significant differences in survival of shrimp was recorded in the probiotic treated test tank. The survival percentage of shrimp in untreated T1 tank was 40% whereas in T2 tank was 80%. Conclusions: These results suggested that administration of Bacillus consortium in the rearing water of shrimp confers beneficial effect on water quality, shrimp growth, disease resistance and shrimp survival.