摘要： 酵母β -D-葡聚糖是一种极富有生物活性的多糖，具有较强的免疫活性以及其它具有医疗作用的功能特性。假丝酵母细胞壁中存在大量的β -D-葡聚糖，所以，如何从酵母的细胞壁中提取纯度高的β -D-葡聚糖是实现全面利用其价值的重要关键。本论文利用土豆淀粉生产过程所产生的废弃液作为假丝酵母的培养基的主要营养源，通过改变pH值（pH值4.0，pH值5.0，pH值7.0）和甘油添加量（5%，10%，15%，20%，25%），设计了15种试验性培养基和一种YPD对照培养基，并且通过测定不同试验性培养基所培养的产朊假丝酵母CICC1769菌株的生物量以及其细胞壁中的葡聚糖含量来筛选出最佳组成的培养基，然后用所筛选出的最佳培养基培养产朊假丝酵母，并用一种新的提取方法提取其细胞壁中的葡聚糖并对葡聚糖进行了纯度和结构分析。实验结果表明：去蛋白土豆汁能够有效的促进产朊酵母细胞壁中葡聚糖的代谢合成，其最佳培养基的构成为在pH值为5.0的条件下甘油的添加量为10%，最佳培养基中假丝酵母的葡聚糖得率为：14.18%。纯度和结构分析表明：诱导自溶-高温浸提-超声波破壁-酶解-脱脂的提取方法到的样品纯度是77.51%，其中蛋白质的含量为6.26%。红外光谱表明：所提取的为β-1,3-葡聚糖，其中不含甘露糖，但含有少量的蛋白质杂质。42843

毕业论文关键词：去蛋白土豆汁；产朊假丝酵母；β -葡聚糖；高效液相色谱；红外光谱

Bio-synthesis of β -glucans of cell wall of the yeast Candida utilis

Abstract：Yeast β-glucans exhibit valuable functional properties, including therapeutic ones.The yeast cell wall contains a large number of β -glucans,therefore, how to extract high purity beta -D-glucans from yeast cell wall is the key to realize its comprehensive utilization.In this paper, the waste produced by the production of potato starch is used as the main nutrient source of the culture medium of Candida.Experiments were performed in 16 variants of experimental media.Experimental media from deproteinated potato juice water were differentiated in terms of glycerol concentration as a carbon source. Doses of 50, 100, 150, 200, and 250 g of glycerol/L deproteinated potato juice water were investigated.Media with deproteinated potato juice water with glycerol were prepared in three different pHs (4.0, 5.0, and 7.0).Control cultures of the yeast trains were cultured in a synthetic yeast extract-peptoneglucose medium (YPD)，which was treated as a reference Medium.Therefore，experiments were performed in 16 variants of experimental media.Each culture variant (in reference to the culture medium) was replicated three times.The optimal composition of culture medium was screened out by measuring the biomass of the CICC1769 strains and the content of beta-glucans in the cell wall of Candida utilis cultured by different experimental medium,and then selected the best medium culture the yeast Candida utilis , and the purity and structure of the glucans were analyzed after a novel method was performed for the extraction of the cell wall glucans.Experimental results show that the protein potato juice can effectively promote the metabolic synthesis of glucan in the yeast cell wall , the optimum culture medium was at pH 5.0 glycerol addition amount is 10%, the yield of Candida yeast glucan in the best culture medium was 14.18%. Purity and structural analysis show that autolysis temperature induced extraction ultrasonic wall breaking enzyme - to skim the extraction method of sample purity is 77.51%. The protein content of 6.26%. Infrared spectrum showed that the extracted β-1,3- glucan, which does not contain mannose, but contains a small amount of proteinimpurities.

Keywords: β-glucan;Deproteinated potato juice water;Candida utilis;high performance liquid chromatograpHy;infrared spectrum analysis