Lipid production by yeast utilizing whey under the influence of microelements and vitamins

ABSTRACT

Candida utilis was allowed to grow on a fermentation medium containing whey as a substitute of carbon and N sources. This medium was supplemented with Fe, Zn, Mn and Cu as trace elements in different levels to determine the optimum concentration of each microelement which causes best growth of the yeast accompanied with higher amount of lipids accumulated within the cells. The optimum concentrations of the tested microelements were 10-4, 10-5, 10-5 and 10-6 M for Fe, Zn, Mn and Cu, respectively. The effect of the four tested vitamins [thiamine, riboflavin, folic acid and nicotinamide] on both growth and lipid production by the yeast was also studied. Addition of thiamine, riboflavin or nicotinamide to the whey-containing media at a level of 0.3 g/l produced a higher growth, while supplementation of the fermentation media with 0.4 g/l folic acid produced maximum growth