Production Of β-Carotene From Blakeslea Trispora

The production of beta-carotene from Blakelea trispora was investigated, which includes the optimation of medium, the fermentation technology, selection of accelerator and the extraction of beta-carotene. The results showed the optimal growth medium was: 3 % glucose, 5% maltodextrint, 0.5 g/L monopotassium phosphate, 0.3 g/L magnesium sulfate, 0.5 mg/L thiamine hydrochloride. The initial pH was 5.5-7.0, the shaker rotate speed was 150 rpm and temperature was 28℃. The optimized fermention mediums was: 20 g/L glucose, 30 g/L soybean protein power, 3 g/L monopotassium phosphate, 1 g/L magnesium sulfate, 0.5 mg/L thiamine hydrochloride. The flask cultures were incubated at 28℃for 120 h under the condition of pH 6.5-7.5, shaker rotate speed 220 rpm with the inoculum of 10 %. The production of beta-carotene was 1.13 mg/L.Optimized by single-factor and orthodox experiments, the addition of asselerator was: 2 % soybean, 0.4 % Span-60, and 0.15 % beta-ionone at the fermentation time of 48 h. After 120 h culture, the production of beta-carotene by Blakelea trispora was 13.79 mg/L.The different methods for the extraction of beta-carotene were also studied: (1)Extraction by organic solvent. The best extraction conditions were acetone:petroleum ether=1:1 at 28℃for 10 h. The extraction rate rise to 298μg/g.(2)Extraction enhanced with ultrasonic wave. The optimal extraction time was 30 min. The extraction rate rise to 311μg/g. (3)Pigment granule. The granule was crushed by adding high concentration of sodium chloride and observed with microscope. The extraction rate rise to 344μg/g.The characteristic absorption peak of beta-carotene was analysed by IR Spectrum.