Studies On Production Of Carotenoid With Rhodotorula Glutinis

Extraction method and fermentation conditions of carotenoid were studied in the paper. Rhodotorula glutins was employed in the study. The high yield strains were obtained through UV mutagenesis. At last the compositions of carotenoid were analyzed.Different methods of breaking cell wall and extracting solvent were compared. The acid-heat method and the solvent of petroleum ether and acetone (1:1) were appropriate.Through single factor experiment, orthogonal test, uniform design and Box-Burman method, the optimal fermented condition were obtained as follows: sucrose40g/L,yeast extract 20g/L, K2SO4 1.0%, MgSO4 7H2O 0.05%, CuSO4 5H2O 0.0045%, VB1 0.2 mg/L,VB2 1.0mg/L, VC 0.7 mg/L, tomato juice 3.0 ml/L, peanut oil 0.8ml/100ml, pH 6.0, medium volume 30ml (in 500ml flask) , 28 C,150rpm and culture time 84h. The cell biomass, carotenoid content and yield could reach 15.63g/L, 941.14 g/g, 14.71 mg/L respectively under the selected optimum conditions.The best conditions of 5L fermentor were as follows: the total sucrose concentration 80g/L, yeast extract 20g/L, sucrose concentration was maintained 10~20g/L, pH6.0, DO15~25%. The fermentation kinetics was studied by MATLAB. Two kinetic models were constructed which could reflect the regularity of growth, production formation in the process of batch fermentation.The start strain was treated with ultraviolet. Carotenoid synthesis inhibitor dipheny-lamine was used in selection of the mutants. Ruv701 was selected through determination of characters of mutants. The mutant has good stabilization of inheritance. The production of carotenoid was increased 42.06% and 62.56% respectively than the start strain in flask and fermentor.TLC and HPLC method were used to separate and identify Rhodotorular glutinis pigments in the text. Four components were separated and one of them could be -carotenoid; others could not be identified accurately here.