本文選題：還原型谷胱甘肽 + 發(fā)酵　； 參考：《大連工業(yè)大學(xué)》2011年碩士論文

【摘要】：還原型谷胱甘肽(reduced glutathione, GSH)是由L-谷氨酸、L-半胱氨酸和甘氨酸縮合而成的一種含有巰基的生物活性三肽化合物,是人體細(xì)胞內(nèi)的主要代謝物質(zhì),具有清除自由基、解毒、促進(jìn)肝酶活性等生理功能。在食品工業(yè)中,GSH亦可起到增強(qiáng)肉類(lèi)風(fēng)味、預(yù)防色素沉著及防止水果褐變等作用。日本等一些發(fā)達(dá)國(guó)家很早就開(kāi)始研究GSH且基本壟斷了中國(guó)市場(chǎng),我國(guó)主要是以微生物發(fā)酵法生產(chǎn)GSH,亟需對(duì)其工藝進(jìn)行優(yōu)化改進(jìn)以提高GSH的產(chǎn)率。本文從中科院沈陽(yáng)應(yīng)用生態(tài)研究所菌種保藏室的酵母菌庫(kù)中篩選得到一株產(chǎn)GSH能力較高的釀酒酵母Y,其GSH產(chǎn)量達(dá)9.60 mg/g。改進(jìn)發(fā)酵培養(yǎng)基配方以促進(jìn)菌體生長(zhǎng)和提高GSH產(chǎn)量,采用添加L-半胱氨酸和補(bǔ)加葡萄糖的策略,使得菌體濃度提高12.4倍,胞內(nèi)GSH產(chǎn)量達(dá)12.94 mg/g干菌體。選用熱水抽提法和乙醇提取法提取胞內(nèi)GSH,通過(guò)單因素實(shí)驗(yàn)和正交實(shí)驗(yàn)對(duì)pH值(A)、提取溫度(B)、提取時(shí)間(0、料液比(D)4個(gè)因素進(jìn)行優(yōu)化,并對(duì)兩種方法的提取效率和提取條件進(jìn)行比較,確定最佳提取方法為熱水抽提法,提取條件：料水比1：3,提取液pH 2.0,90℃水浴中提取10min, GSH的提取量可達(dá)14.27 mg/g。為了提高GSH純度,采用離子交換和葡聚糖凝膠層析技術(shù)分離純化提取液中的GSH。通過(guò)靜態(tài)實(shí)驗(yàn)優(yōu)化分離條件：D0017陽(yáng)離子交換樹(shù)脂,提取液上柱pH 4.5,用pH 7.0磷酸氫二鈉-檸檬酸鹽緩沖液+03 mol/L NaCl進(jìn)行洗脫,將最優(yōu)條件應(yīng)用于上柱分離實(shí)驗(yàn)中,柱高15 cm,洗脫流速2.0 mL/min, GS H回收率為91.46%。將GSH濃度大于250μmol/L的部分進(jìn)行冷凍干燥,濃縮后上Sephadex G-10凝膠層析柱,再次純化,最佳純化條件為：柱高45 cm,上柱量為柱體積10%,去離子水洗脫,流速為10 mL/min,GSH回收率為86.18%,雜蛋白去除率為87.6%。由實(shí)驗(yàn)結(jié)果可知,熱水抽提法提取GSH耗時(shí)短、無(wú)污染、提取徹底,用離子交換法和葡聚糖凝膠層析分離純化GSH效果好、操作簡(jiǎn)便、能較好的去除雜蛋白,有利于工業(yè)化生產(chǎn)。
[Abstract]:Reduced glutathione glutathione (GSH) is a bioactive tripeptide compound containing sulfhydryl group, which is formed by condensation of L-glutamic acid L-cysteine and glycine. It is the main metabolite in human cells and has the ability to scavenge free radicals and detoxify.Promote liver enzyme activity and other physiological functions.GSH can also enhance meat flavor, prevent pigmentation and prevent fruit browning in food industry.Some developed countries, such as Japan, have been studying GSH for a long time and have basically monopolized the Chinese market. In our country, the production of GSH is mainly by microbial fermentation, so it is necessary to optimize and improve the process to increase the yield of GSH.A Saccharomyces cerevisiae Y. with high GSH production capacity was obtained from the yeast bank of Shenyang Institute of Applied Ecology, Shenyang Institute of Applied Ecology, Chinese Academy of Sciences. Its GSH yield was 9.60 mg / g.The fermentation medium formulation was improved to promote the growth of bacteria and increase the GSH yield. By adding L- cysteine and glucose, the cell concentration was increased by 12.4 times, and the intracellular GSH production reached 12.94 mg/g dry bacteria.The intracellular GSH was extracted by hot water extraction and ethanol extraction. The extraction efficiency and extraction conditions of the two methods were compared by single factor experiment and orthogonal experiment. The four factors of pH value, extraction temperature, extraction time and ratio of material to liquid were optimized by single factor experiment and orthogonal experiment.The optimum extraction method is hot water extraction. The extraction conditions are as follows: the ratio of material to water is 1: 3, the pH value of the extract is 2. 0 ~ 90 鈩，

本文編號(hào)：1752432