Manipulation of temperature and illumination conditions for enhanced beta-carotene production by mutant 32 of Rhodotorula glutinis

Abstract

Aims: Enhancement in the production of beta-carotene by the hyper producer mutant 32 of Rhodotorula glutinis by manipulation of temperature and illumination.

Methods and results: Growth and beta-carotene production was investigated in a 1 litre fermenter at different temperature and illumination conditions. The optimum temperature for growth and beta-carotene production was 30 and 20 degrees C, respectively. At 30 degrees C, beta-carotene production was 125 +/- 2 mg l-1 and accounted for 66% of the total carotenoids in 72 h; at 20 degrees C, it was 250 +/- 7 mg l-1 and accounted for 92% of total carotenoid content. Continuous illumination of the fermenter by 1000 lx white light hampered growth as well as carotenoid synthesis. At 30 degrees C, illuminating the fermenter in late logarithmic phase resulted in a 58% increase in beta-carotene production with a concurrent decrease in torulene; at 20 degrees C, however, it showed no appreciable increase.

Significance and impact of the study: Proper manipulation of culture conditions enhanced beta-carotene production by R. glutinis which makes it a significant source of beta-carotene.