Research On Production Of Trehalose With Yeast

In this paper, the method of measuring trehalose, the tolerance traits of yeast, screening of yeast with high trehalose as well as the fermentation technology for the production of trehalose with yeast were studied.The method of trehalose measuring was studied. It includes the confirmation of the length of boiling time, the confirmation of the length of spectrum of measurement and the standard curve of trehalose. The results showed the optimal boiling time is ten minutes. The optimal length of spectrum is 630nm, the formula of calculating trehalose in yeast were got from the standard curve of trehalose.The trait of tolerance of 11 yeast and correlation between tolerance trait and content of trehalose in yeast were studied. The result showed that :the more CO2 produced by the yeast under the condition of 6% sodium chloride in the medium, the more trehalose accumulated in the yeast and the stronger the talent of fermenting glucose in the medium with the condition of 0.4% acetic acid. In addition, the tolerance of alcohol and frozen have no correlation with the content of trehalose in the yeast.Through the tests, the strain of Y7, which had the highest content of trehalose, and strong tolerance to sodium chloride, was used for mutation with EMS. The test of sordium chloride tolerance was used for primary screening, and the test of trehalase and tolerance to acetic acid was used for further screening. The measurement of trehalose content was used for precise screening. Three mutants with higher trehalose content were got. Compared with Y7, the content of trehalose of L61 was raised by 11%.The L61 was used to study the fermentation technology. The effect of ingredient, raising the pH of liquor, heat shock culture and adding salt to feeding culture were studied.The result shows that the optimal medium is as follows: molasses 12Brix, (NH4)2SO4 0.05%, biotin 1.5ug/100Ml, VB, 30ug/100mL.Raising the pH of fermenting liquor to pH6.2 at 12~13h,adopt salt feeding culture(feeding salt at 20g/L) at 12h,and heat shock at 39癈 at 12~ 13h,the content of trehalose raised to 25.8%,and the amount of trehalose of trehalose reach 9.6g/L.