The growth of yeast

Abstract

Growth is only exponential as long as the relative growth rate remains constant. This is usually so with yeast when it is grown under aerobic conditions with a sufficient supply of sugar and some other growth essentials. The sugar is then continuously consumed to provide the ‘C skeletons’ and the energy for the growth of new yeast cells and for maintenance of the yeast. The end-products, CO₂ and H₂O, of the sugar broken down in the respiratory process do not pollute the environment of the yeast. However, if yeast grows under anaerobic conditions, one end-product of the respiratory processes is alcohol which may accumulate in the environment. This slows down and ultimately stops the development of yeast buds even when there is still enough sugar available for growth.