Effect of the concentration of L-Phenylalanine and lactose on 2-Phenylethanol production by whey fermentation using the yeasts Kluyveromyces marxianus and Debaryomyces hansenii under co-culture mode

Abstract

Whey is a by-product generated by the dairy industry which contains lactose and proteins. As a valorization method, fermentation is a biotechnological practice to obtain high value-added biomolecules from whey, such as 2-Phenylethanol (2PE). Sterilization methods were assessed to determine which was more appropriate for whey fermentation using Kluyveromyces marxianus and Debaryomyces hansenii under co-culture mode. Then, the effect of lactose and L-Phenylalanine (L-Phe) initial concentrations on the production of 2PE was studied using a central composite design. The initial concentration of lactose and L-Phe of 40 g/L and 4 g/L respectively, allowed to obtain the highest concentration of 2PE (2.55 ± 0.12 g/L). The main effect of lactose on the production of 2PE was the vigorous induction of yeast growth in 24 h of fermentation. The L-Phe presence in the culture medium promoted the production of 2PE during the yeast's secondary metabolism, corresponding to the stationary growth phase.