Breeding Of Red Yeast Yielding Beta-carotene Pigment Separation, Purification And Identification

β-carotene is one of the most important carotenoids in food.It can effectively protect cells from free radical damage to sustain the metabolism of the cells,slow down the aging process,prevent and treat the related diseases,cancer in particular and improve the immune system.β-carotene is a promising market.Rhodotorula,as a main source, has several advantages in producingβ-carotene.For instance,comparatively simple culture conditions,lower costs,short cycle time,and nontoxic bacteria with high protein. Besides,it is easy for industrial production.Based on the above mentioned merits, Rhodotorula has become the focus of recent researches on how to produceβ-carotene in an efficient,safe and cost-effective way.The methodology of this paper is to screen one out of 15 Rhodotorula from the wild,namely the SCAU-3-2,and then the author of this paper selected and optimized this Rhodotorula's main nutrition and environment.Seven mutant strains were obtained from the parent strain SCAU-3-2 by UV mutagenesis.After testing their biomass and capacity of carotenoid,the author screened out the mutant strain MUT-Y-5 that can dramatically enhance the productivity ofβ-carotene.The strain MUT-Y-5 has passed the stability test.Then the author optimized the culture conditions of MUT-Y-5.Finally,the acetone extract of both strain SCAU-3-2 and the mutant strain MUT-Y-5 was isolated,purified and identified by Thin layer chromatography(TLC),column chromatography and UV-Vis and a comparative analysis was conducted.The major findings are as follows:1.The best culture conditions of the strain SCAU-3-2:glucose:30g/L;peptone: 5g/L;yeast powder:5g/L;media amount 30 mL/250 mL(flask);starting at pH 6.5;and fermentation time:96 hours.Under this condition,the strain's biomass and carotenoid content are up to 15.2g/L and 621.0μg/g respectively.2.As for the mutant strain MUT-Y-5,under the conditions of media amount 30/250 (mL/mL),starting at pH 6.5,temperature:28℃,fermentation time:96 hours,the best combination between carbon and nitrogen is as follows:glucose(30g/L);peptone:5g/L; yeast powder:5g/L.Under this circumstance,the mutant strain's biomass and carotenoid content are up to 14.7 g/L,952.6μg/g respectively.The carotenoid content has been enhanced by 54.8%.3.Both strain SCAU-3-2 and MUT-Y-5 generate the same kinds of carotenoid,namelyβ-carotene,torulene and torularhodin;and a unsaturated fatty.By conducting a further analysis,The proportion among theβ-carotene,torulene,and torularhodin in SCAU-3-2 is 16:61:23;while the one in MUT-Y-5 is 77:12:11.Theβ-carotene in MUT-Y-5 is 4.8125 times more than the original one,which is a sound prove that the mutant strain MUT-Y-5 is a highβ-carotene production strain.