【作者】 郭建辉；

【导师】 赵华；

【作者基本信息】 天津科技大学 ， 发酵工程， 2005， 硕士

【摘要】 本论文研究了UVB照射培养对酵母菌生长、生理性能和活性成分的影响,确定了UVB照射培养后酵母细胞的最佳酶解条件,并对活酵母细胞衍生物(LYCD)在化妆品中的应用进行了研究。 1.UV-B照射会影响酵母菌的生长繁殖,尤其是在接种量较小时(小于1×10~7/mL),酵母菌生长受到UV-B的影响较明显,而在较大接种量时影响较小。使用pH5.0的柠檬酸-柠檬酸钠缓冲溶液配制培养基可以降低UV-B照射培养过程中酵母的死亡率。在UVB照射培养过程中,酵母细胞的絮凝性随培养时间的延长逐渐增强,说明酵母细胞在UVB照射培养过程中,细胞壁的组成发生了某些变化。 2.在UV-B照射培养过程中,酵母菌为抵御紫外线的伤害,细胞内会发生复杂的生物化学变化,各种活性物质的含量也随之发生变化,其中核酸、蛋白质、海藻糖、麦角甾醇和葡聚糖含量均有不同程度的提高,而酵母细胞中谷胱甘肽的含量和超氧化物歧化酶活性则均呈下降趋势。 3.对影响细胞酶解破壁的各单因素条件进行了研究,并结合正交试验分析,确定了破壁的最佳条件为:12%的酵母悬浮液中添加3%的蛋白酶(细胞干重),pH6.0,恒温50℃水浴震荡28h。添加1%的纤维素酶可以提高酶解破壁的效果。 4.对LYCD的主要成分进行了分析。认为其含有通过O-型糖肽键相连的小分子糖肽。 5.涂抹添加了LYCD的防裂护肤霜的皮肤电导率比涂抹普通护肤霜提高10-20%,说明添加LYCD的防裂护肤霜保湿效果得到较为明显的提高。更多还原

【Abstract】 The effects of UVB on the growth of yeast, physiological properties and substances were studied. The optimum hydrolysis condition of yeast cells cultured by UVB was determined, and the application of Live Yeast Cell Derivative (LYCD) in cosmetic was studied.1. UVB radiation had the effects on the growth of yeast. It was apparent when the inoculation was less than 1×10~7/mL, but the effects were not significant different if the inoculation was raised. The death rate of yeast was decreased when the medium was made with pH5.0 citric acid-natrium citrate buffer solution. Yeast cell agglutinated with the prolonged time of the UVB culture, which proved that the structure of cell wall was changed in the UVB culture.2. The results showed that the contents of RNA, protein, trehalose, ergosterol and glucan in yeast cells increased to a certain extent. But the contents of GSH and the activity of SOD decreased. UV-B influenced greatly the growth of yeast, and different changes of many kinds of physiological substances contents had appeared.3. The optimum hydrolysis condition of yeast cells cultured by UVB was determined with orthogonal test after the factors that influenced the hydrolysis were studied respectively. The optimum processes condition was that the suspension of yeast cell 12%, neutrase 3% (dry weight of the cells), pH6.0, 50 ℃ and the time of hydrolysis 28h. The effects of hydrolysis could be improved by adding cellulase 1%.4. The components of LYCD were analyzed. A little molecule glycopeptide with O-glucopeptide bond was found.5. The electric conductivity of skin smeared with moisturizing frost adding LYCD increased from 10-20% according the control, which proved that the moisturizer effects of skin cream increased after adding LYCD.更多还原