Production of pyruvic acid with Candida glabrata using self-fermenting spent yeast cell dry powder as a seed nitrogen source

Abstract

Pyruvic acid is an important organic acid and a key industrial raw material. It is widely used in the chemical, agricultural, and food fields. Candida glabrata is the preferred strain for pyruvic acid production. The waste yeast cell for pyruvic acid fermentation with C. glabrata are rich in protein, amino acid, nucleic acid, and vitamins, as potential and cost-effective nitrogen source raw material. In this study, the potential of C. glabrata to produce pyruvic acid using spent yeast cell dry powder was evaluated. When 30 g/L of spray-dried spent yeast cell powder was used as the seed nitrogen source, a high titer of pyruvic acid was obtained. The pyruvic acid production reached 63.4 g/L with a yield of 0.59 g/g in a 5 L bioreactor. After scale-up to a 50 L bioreactor using the fermented spent yeast cell dry powder as a seed nitrogen source, 65.1 g/L of pyruvic acid was harvested, with a yield of 0.61 g/g. This study proposes a promisingapproach for increasing the pyruvic acid titer and reducing the costs. Graphical Abstract

Current advances for omics-guided process optimization of microbial manufacturing

“…Thus, rational use of inorganic nitrogen source also plays a positive role in stabilizing and regulating pH during the fermentation process. The organic nitrogen sources including yeast extract, corn steep liquor, and peptone, not only provide nitrogen sources, but also provide inorganic salts, vitamins and growth factors (Lu et al 2022 ), and the nitrogen utilization varies with different organic nitrogen sources during cell growth and product synthesis (Lu et al 2011 ). Hence, utilization of multiple nitrogen sources is an efficient strategy to balance the growth and metabolite synthesis during fermentation for the purpose of improving the yield (Crepin et al 2017 ).…”