OPTIMIZATION OF PROCESS PARAMETERS FOR THE PRODUCTION OF ANTIBACTERIAL COMPOUND BY A NEWLY ISOLATED NOCARDIA CYRIACIGEORGICA, KD-15 STRAIN FROM KAZIRANGA NATIONAL PARK OF NORTH EAST INDIA

摘要

Objective: An attempt has been made to evaluate the optimal cultural conditions for obtaining high yields of bioactive metabolites. Methods: A strain of actinobacteria was isolated from the soil sample of Kaziranga National Park of Assam. Strain was identified on the basis of biochemical test as well as 16SrDNA sequence . The strain was tested for antibacterial activity using agar well diffusion method and to enhance its growth and metabolite production, the strain was cultured at different carbon and nitrogen sources and at different pH, salinity and temperature. Results: The strain was identified as Nocardia cyriacigeorgica. The secondary metabolites exhibited excellent antimicrobial activity against dreaded human pathogenic bacteria Staphylococcus aureus (MTCC 96), Bacillus subtilis (MTCC 441), Escherichia coli (MTCC 739) and Pseudomonas aeruginosa (MTCC 2453). The strain utilized glucose as good carbon source for growth and starch for metabolite production. Soybean meal and beef extract were the nitrogen sources for the elaboration of both growth and bioactive metabolites. The optimum temperature, salinity and pH for growth and bioactive metabolite production of the strain were recorded as 28±2 o C, 1.5% and 7.5 respectively. Conclusion: As our results showed the potency of N. cyriacigeorgica as an antibacterial agent under these optimal conditions, so further study can be carried out in this regard. This is the first report of production of antibacterial compound from this emerging pathogenic strain N. cyriacigeorgica . Keywords: Bioactive metabolites, Nocardia cyriacigeorgica , Optimization, Pathogenic bacteria.