高产类胡萝卜素红酵母的筛选及发酵条件的优化

以自然环境中水池边红色附着物、公共浴室红色附着物、空气、果园土壤、汽车修理厂土壤、醪糟、葡萄汁为红酵母菌株初分离材料,采用酸热破壁法提取菌株类胡萝卜素,根据单位体积发酵液类胡萝卜素产量确定了一株高产红酵母(Rhodotorula sp.)菌株R3-2,进一步对其形态、生理生化特性、最适碳源和氮源、培养条件、生物量、类胡萝卜素含量和产量进行了初步研究。结果表明,R3-2菌株为红酵母(Rhodotorula sp.),其所产色素主要为β-胡萝卜素,该菌株的最佳发酵条件为:葡萄糖30 g/L,蛋白胨5 g/L,酵母粉5 g/L,装瓶量30 mL/250 mL,起始pH 6.5,发酵温度28℃,发酵时间96 h。在此发酵条件下其生物量、类胡萝卜素含量和产量分别达到17.6 g/L、639.8μg/g,11.3 mg/L,较原始培养基生物量有所降低,但类胡萝卜素含量和产量分别提高了44.0%和31.39%。

Screening of Rhodotorula Producing Carotenoid and Optimizing its Fermentation Conditions

Based on the preliminary parting materials in the natural environment such as the red attachments on the pool side and in the public bathroom,air,orchard soil,auto repair shop soil,laozaoping and grape juice,carotenoids of these strains were extracted using acid heat broken method.A strain of high carotenoids yields Rhodotorula sp.named R3-2 was screened according to the carotenoid production in the fermentation broth per unit volume.The features of its patterns,physiological and biochemical characteristics,the optimal carbon source and nitrogen,the cell biomass,carotenoids content and yield were further studied in this paper.The results suggested that the pigment production of R3-2 strain was mainly β-carotene.Its optimum fermentation conditions were as follows: glucose 30 g/L,tryptone 10 g/L,yeast extract 5 g/L,medium 30 mL(in 250 mL flask),initial pH 6.5 and culture time 96 h at 28 ℃.Although the cell biomass was 17.6 g/L which was a little lower,carotenoids content and yield could respectively reach 639.8 μg/g and 11.3 mg/L,which were respectively increased by 44.0% and 31.39% in contrast with those of the original medium.