John Thomas

The bioactive compounds from Actinomycetes have antibacterial, anticancer, antioxidant, and antifungal properties. The antioxidant activity of ethyl acetate extract of Bacillus licheniformis was determined by carrying out several assays. Preparation of a bioactive feed encapsulated with sodium alginate and chitosan was carried out for treating the bac- terial infection in Macrobrachium rosenbergii. An experimental trial with three diferent groups was conducted to determine the efect of crude extract of B. licheniformis against pathogenic bacteria, Aeromonas hydrophila in freshwater prawn, M. rosenbergii. The frst group of prawns was given commercial diet. The second group of prawns challenged with A. hydrophila was given commercial feed. The third group of A. hydrophila challenged prawns was given the encapsulated B. licheniformis feed. The survival percentage of prawns was decreased in group 2 compared to the prawns of group 1 and group 3. The anti- oxidant properties were found to be signifcantly increased in case of group 3 prawns. Real time Reverse transcription - Polymerase chain reaction (RT-PCR) study of three diferent groups with three immune genes - Superoxide dismutase (SOD), Crustin and Prophenolox- idase was carried out and antioxidant enzymatic activity, and immunological parameters were recorded. Group 1 was designated as control, injected with saline. Group 2 was desig- nated as infected, challenged with A. hydrophila and group 3 as treated, challenged with A. hydrophila and injected with crude extract of B. licheniformis. The results revealed that the SOD and Prophenoloxidase of gills and hemolymph showed highest gene expression in the case of treated group compared to the infected and control group. The data indicated that B. licheniformis showed enhanced antioxidant activities, immune response, disease resist- ance, and gene expression in M. rosenbergii challenged with A. hydrophila.