Studies on effect of media components on growth and b-carotene production by Rhodotorula graminis RC04

Abstract

Red pigmented yeast wasisolated from a freshwaterriverflowing through mining area of Goa. The isolate was identified as Rhodotorula graminis using morphological, biochemical and physiological features. This isolate showed the presence of pigments beta-carotene, torulene and torularhodin. Effect of different carbon and nitrogen sources was checked on biomass and beta-carotene production. Among the inorganic salts, the isolate grew best with potassium nitrate. Although the yield of total beta-carotene/gram of biomass was less than compared with other inorganic salts of nitrogen used in this study, the total beta-carotene production was found to be maximum. Amino acids supported accumulation of beta-carotene but gave poor yield. Complex nitrogen sources are the best substrates for growth and beta-carotene production. Among these, yeast extract isthe best nitrogen source for growth and beta-carotene production. Glucose appears to be the best carbon source for biomass and beta-carotene production followed by glycerol. Highest beta-carotene production was observed at a 10:1 carbon to nitrogen ratio.