Saccharomyces cerevisiae is being used for long as a rich source of proteins, sugars, nucleotides, vitamins and minerals. Autolyzed and hydrolyzed yeast biomass has found numerous applications in the health food industry as well as livestock feeds. Here, we have compared three lysis methods for production of yeast lysates using autolysis, plasmolysis (ethyl acetate 1.5%), and enzymatic hydrolysis (Alcalase 0.2%). The efficiency of each process was compared according to soluble solid and protein contents, cell lysis monitoring, and release of intracellular materials, cell viability and microscopic analysis. Results showed that plasmolysis by ethyl acetate was found to be more efficient compared to autolysis, with a higher recovery of yeast extract (YE) content. In comparison, the content of released solids and proteins were higher during the enzymatic hydrolysis using Alcalase compared to autolysis and plasmolysis treatments. The highest decrease in optical density of 600 nm was monitored for the hydrolyzed cells. Besides, we defined "Degree of Leakage (DL)" as a new index of the lysis process, referring to the percentage of total released proteins from the cells and it was estimated to about 65.8%, which represents an appropriate indicator of the cell lysis. The biochemical and biophysical properties of the hydrolyzed yeast product as well as its biological activity (free radical scavenging activity and bacterial binding capacity) suggest that Alcalase could be used to accelerate the lysis of yeast cells and release the valuable intracellular components used for foodstuffs, feed and fermentation media applications. Production of baker's yeast lysates using autolysis, plasmolysis, and enzymatic hydrolysis methods.

中文翻译：

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面包酵母（Saccharomyces cerevisiae）的自溶、质壁分离和酶水解：一项比较研究

长期以来，酿酒酵母一直被用作蛋白质、糖类、核苷酸、维生素和矿物质的丰富来源。自溶和水解酵母生物质已在健康食品工业和牲畜饲料中得到了大量应用。在这里，我们比较了使用自溶、质壁分离（乙酸乙酯 1.5%）和酶水解（Alcalase 0.2%）生产酵母裂解物的三种裂解方法。根据可溶性固体和蛋白质含量、细胞裂解监测、细胞内物质的释放、细胞活力和显微分析，比较每个过程的效率。结果表明，与自溶相比，乙酸乙酯的质壁分离效率更高，酵母提取物 (YE) 含量的回收率更高。相比下，与自溶和质壁分离处理相比，使用 Alcalase 的酶促水解过程中释放的固体和蛋白质的含量更高。对于水解细胞，监测到 600 nm 光密度的最大降低。此外，我们将“渗漏度（DL）”定义为裂解过程的新指标，指的是细胞释放的蛋白质总量的百分比，估计约为65.8％，这是细胞裂解的合适指标. 水解酵母产品的生化和生物物理特性及其生物活性（自由基清除活性和细菌结合能力）表明 Alcalase 可用于加速酵母细胞的裂解并释放用于食品的有价值的细胞内成分，饲料和发酵培养基应用。使用自溶、质壁分离和酶水解方法生产面包酵母裂解物。