.....This process, however, has problems and drawbacks. One of the obvious problem is the use of a batch process which causes a substrate inhibition in the yeast propagation where all the sugar is added prior to yeast pitching. Second, due to this high quantity of sugar, a catabolite repression is observed or also known as the "crabtree effect" which changes the yeast metabolism and undergoes fermentation even with supply of oxygen at elevated glucose concentratin of 0.02 - 0.85mM......