Introduction
Candida utilis (Lindnera jadinii) is a Crabtree effect-negative yeast that is currently used to produce several industrially important compounds, such as glutathione and RNA [1]–[3]. C. utilis can grow on inexpensive substrates, such as pulping-waste liquors from the paper industry [4], and high cell density culture and large-scale production are possible under efficient continuous-culture conditions [1]. Furthermore, C. utilis is able to assimilate nitrate, a naturally occurring mineral source of nitrogen found as potassium nitrate. Along with Saccharomyces cerevisiae and Kluyveromyces fragilis, dried C. utilis cells have been approved for use as a food additive by the Food and Drug Administration [1]. In addition, since efficient methods of C. utilis transformation have been developed [5]–[7], the yeast has been used for the heterologous production of monellin, α-amylase, carotenoids, and organic acids such as L-lactic acid [8]–[12].