Comparation on synthesis and release of mannan in four yeasts

The synthesis and release rules of mannan on cell walls was compared during the cultivation process of candida utilis, pichia pastoris, bread yeast and beer yeast in this research. It was found that the syntheses of mannan in these four yeasts were all growth coupling type. Synthetic ability of mannan in different types of yeast were significantly different ( p < 0. 05) . The synthetic ability of mannan in beer yeast, which had the strongest synthetic ability among these four yeasts, was 0.62g/L fermentation broth, while that in pichia pastoris was only 0.47g/L fermentation broth. It was indicated that all the maximal releasing rates of mannan in four kinds of yeasts appeared in the middle period of logarithmic growth and the maximal releasing rates of mannan in different types of yeasts differed significantly, i.e., the maximal releasing amount of mannan in pichia pastoris, which was highest among these four kinds of yeasts, reached to 0.27g/L fermentation broth, while the maximal releasing amount of manna in beer yeast, which was the lowest among these four kinds of yeasts, was only 0.15g/L fermentation broth. It was showed that alcohol significantly stimulated the releasing of mannan in four kinds of yeasts ( p < 0. 05) . Candida utilis in the alcohol with a concentration of 5 % was affected most significantly. The releasing amount and releasing rate of mannan in it were respectively increased by 152% and120% as compared with the control (p<0.05) .