Abstract:

A strain of Rhodotorula sp. was mutagenized with UV radiation and the mutant stain was adopted to produce carotenoid. The effects of glucose concentration and initial pH of fermentation medium, temperature and fermentation time on carotenoid production were investigated by single-factor method. An orthogonal array design leading to a set of 9 combinations of the four variables was conducted to attain the highest carotenoid yield. The UV mutagenization for 30 s resulting in about 80% mutation rate was chosen to obtain high-yield carotenoid-producing mutant strains. The optimal conditions for improved carotenoid production was determined as follows: glucose concentration 2.5%, initial pH 5.0, temperature 28 ℃, and fermentation time 120 h. Under these conditions, the carotenoid yield was found to reach 11.61 mg/L, higher than that by starting stain.

Key words: Rhodotorula sp., carotenoid, UV mutagenization, optimization