Studies on Optimization of Growth Parameters for Mass Multiplication of Actinobacteria

Abstract

Aim: To isolate, characterize and optimize the growth parameters for mass multiplication of Actinobacteria. Place and Duration of Work: The study was carried out in Department of Agricultural Microbiology, GKVK, University of Agricultural Sciences, Bangalore during 2019-20. Methodology: Actinobacterial isolates were characterized morphologically and screened for optimization of growth parameters viz., pH, temperature, salt concentration and utilization of carbon source for their mass multiplication. Results: Forty actinobacterial isolates were enumerated from rhizosphere soil of finger millet, cowpea and also from different organic manures. Color of aerial mycelium in most of the actinobacterial isolates were white, grey or cream with dry, cottony or powdery appearance. All forty isolates were Gram positive, non-acid forming and motile. During optimization of growth parameters, results showed that all the actinobacterial isolates growth was observed good at 30℃, pH 7 and 2 per cent NaCl concentration. Starch was confirmed as the best carbon source for all the actinobacterial isolates during carbon source utilization ability. Conclusion: Based on the results, it is showed that all the actinobacterial isolates enumerated were aerobic, spore-forming, Gram positive bacteria, non-acid forming and motile. Maximum growth of Actinobacterial isolates was obtained at temperature of 30℃, pH 7 and 2 per cent NaCl concentration with the ability of growing on ten different carbon sources during the optimization of nutritional and cultural characterization studies. Among the different carbon sources, starch was confirmed as the best carbon source for all the isolates during the study of carbon source utilization ability.