ASSESSMENT OF BIO-PROCESS VARIABLES FOR THE ENHANCED PRODUCTION OF CAROTENOID PIGMENT BY SOIL ISOLATE RHODOCOCCUS kroppenstedtii
Bio-process variables Optimization in Rhodococcus kroppenstedtii.
Natural pigments like carotenoids are known for possessing an extensive range of health promoting antioxidant, antibacterial and anticancer properties. Rhodococcus kroppenstedtii has the potential to produce an intense red carotenoid pigment. There are various factors influencing the pigments productions, among which are the nutrient media composition, pH, temperature, aeration, incubation time and inoculum concentration. This study aimed at improving the medium composition for efficient and economical production of pigment. The present research work revealed the influence of various physical parameters such as temperature, pH, inoculum %, aeration, and incubation time as well as nutritional parameters such as sugars, organic and inorganic nitrogen, metal ions and phosphates on the biomass, pigment and pigment production rate in Rhodococcus kroppenstedtii. In the present study optimum cultural parameters were determined to obtain the enhanced production of carotenoid pigment. This research study focuses that the maximum growth and pigment production in Rhodococcus was achieved when inoculated with 2% inoculum at 37°C, pH 7.0 with shaking at 120-150 rpm up to 48 hours. Among the various sugars studied as a carbon source maximum biomass and pigment production rate was found with sugar sucrose and mannitol. Studies on the influence of various inorganic and organic nitrogen sources revealed that yeast extract and beef extract among the organic nitrogen and ammonium chloride as an inorganic nitrogen source was found to boost the pigment production in Rhodococcus kroppenstedtii. Out of the various metal ions MgSO4 and CaCl2 was found to enhance the pigment production while K2HPO4 as the best phosphate source for biomass and pigment production in isolate. When shake flask experiment containing optimized media was conducted, it revealed that two fold increase in pigment production was achieved in optimum physico – chemical nutritional parameters as compared to growth of isolate in basal medium.