产类胡萝卜素酵母菌的筛选及色素稳定性分析

该研究从赤霞珠酿酒葡萄表皮分离高产类胡萝卜素的酵母菌株，并研究了温度、氧化剂、还原剂及酸度调节剂等因素对菌株所产类胡萝卜素稳定性的影响。结果表明，从酿酒葡萄表皮分离到6株产类胡萝卜素较强的酵母菌，其中酵母菌Y7在以葡萄糖为碳源、蛋白胨为氮源的液体培养基中类胡萝卜素产量较高。经形态观察、生理生化特性和ITS基因序列分析鉴定，菌株Y7属于粘红酵母（Rhodotorula glutinis）。酵母菌生产色素的基本稳定性良好，但高温（＞40 ℃）、添加氧化剂（H2O2）、还原剂（亚硫酸钠、抗坏血酸）和酸度调节剂（柠檬酸、柠檬酸钠）使其稳定性下降，但影响较小，加入苹果酸和氢氧化钠对类胡萝卜素有增色的效果。研究结果将为粘红酵母Y7在类胡萝卜素商业化生产中的应用提供参考。

Screening of carotenoid-producing yeast and pigment stability analysis

In this study, a high-yield carotenoid yeast strain was isolated from the epidermis of Cabernet Sauvignon wine grapes, and the effect of temperature, oxidants, reducing agents, and acidity agents on the stability of the carotenoid produced by the strain was investigated. The results showed that six yeast strains with high-yield red pigment were isolated from grape epidermis, and the carotenoid yield of yeast strain Y7 was higher in liquid medium with glucose as carbon source and peptone as nitrogen source. According to the result of morphological observation, physiological and biochemical characteristics, and ITS gene sequence analysis, the strain Y7 was identified as Rhodotorula glutinis. The carotenoid produced by strain Y7 had good stability, and the stability decreased under the conditions of high temperature (＞40 ℃), addition of oxidant H2O2, reducing agents (sodium sulfite, ascorbic acid), and acidity regulator (citric acid and sodium citrate), but the effect was little. Addition of malic acid and sodium hydroxide had enhancing effect on red pigment color. The results will provide reference for the application of R. glutini Y7 in the commercial production of carotenoids.