METABOLISM OF CHEESE WHEY LACTOSE BY KLUYVEROMYCES-FRAGILIS FOR ENERGY AND GROWTH UNDER BATCH CONDITION

The fermentation of lactose by Kluyveromyces fragilis is an exothermic reaction in which heat is released, resulting in a rise in reactor temperature. A heat balance was performed on a 5-L batch reactor used for single cell protein (SCP) production to determine the portions of cheese whey lactose used for energy and growth. On the average, about 88% of lactose was used for growth, and 12% was used for energy. The lactose consumed during the lag and stationary phases was used mostly for cell endogenous growth and respiration, whereas that consumed during the exponential growth phase was used for cell multiplication and energy. The heat released varied from 6.5 to 8.9 kJ/g,cell. Because of the proper design of the fermenter, the temperature of the medium did not rise above 33-degrees-C; thus, no cooling system was needed.