Yeast single cell protein production from a biogas co-digestion substrate

Abstract

Biogas plants serve as hubs for the collection and utilization of highly nutritious waste streams from households and agriculture. However, their outputs (biogas and digestate) are of relatively low economic value. Here, we explore the co-production of yeast single cell protein, a potentially valuable feed ingredient for aquaculture and other animal producing industries, with biogas on substrate collected at a co-digestion biogas plant, using three yeast species well suited for this purpose (Wickerhamomyces anomalus, Pichia kudriavzevii, and Blastobotrys adeninivorans). All yeasts grew rapidly on the substrate, yielding 7.0–14.8 g l⁻¹ biomass after 12–15 The biomass crude protein contents were 22.6–32.7 %, with relatively favorable amino acid compositions mostly deficient in methionine and cysteine. Downstream biomethanation potential was significantly different between yeast species, with the highest product yielding species (Blastobotrys adeninivorans) also yielding the highest biomethanation potential.