| In this paper, saccharomyces cerebisiae2144had been chosen for studying on toleranceunder extreme condition. This paper studied on intracellular protein, extracelluar secretprotein and extracelluar organic acid metabolism change with YNB medium. In its naturalhabitat environment and industrial cultivation process, Saccharomyces cerevisiae mayencounter several environmental stresses, such as saline stress, sugar stress. Therefore, thisstudying aimed to provide theoretical base for industry production.1. The results of experiments show that high sugar and normal condition saccharomycescerebisiae. Cells in logarithmic phase phase were longer with suger concentration raising. Instable phase, appeared next growth. There were major difference in cells growth and fallingsugar condition with high sugar and normal condition; In high sugar concentration, decliningsugar were fast, but in stable process delining sugar is stable;in medium pH is decliner thannormal in primary process and in stable process pH is similar; the trend of yeast intracellulartrehalose change is consistent with sugar concentration change; Intracellular and extracelluarglycerine change is increasing in high sugar, but glycerine content were stable in normalgroup.2. Separated and analyzed yeast protein with Sephadex G-25, Sephadex G-75andSDS-PAGE, the results showed that yeast growth under extreme condition, in order to adaptenvironment change，extracelluar protein metabolism change and protein bands appeared anddisappeared. Especially extracelluar secretory protein, small molecular weight proteinsdiscrepancy was very obvious, and big molecular weight acidity proteinase54Kda was thesame as proteinase A zymogen by SDS-PAGE analyzing. So proteinaseA zymogen wassecreted to extracelluar. All of these are the ways that yeast improved tolerance under extremecondition.3. The study showed that malic acid, citric acid, lactic acid and α-ketoglut arate, fourkinds of extracelluar organic acid metabolism was influenced by high sugar concentration.But metabolism change discrepancy was very obvious. The study illustrates that in order toadapt extreme condition, that yeast metabolism on organic acid and change content is also a effective way for new environment. |
