Energy-translation coupling limits anaerobic yeast growth.

Abstract

Understanding how nutrient-specific limitations shape anaerobic metabolism in Saccharomyces cerevisiae is essential for defining the physiological limits of yeast growth. Integrating chemostat physiology, multi-omic profiling, and targeted metabolic engineering under strictly anaerobic conditions, we show that yeast maintains a conserved maximum glucose uptake (~14 mmol/gDW/h) under carbon (C), nitrogen (N), and phosphorus (P) limitation, while distinct regulatory bottlenecks constrain maximal growth rate: ATP insufficiency under C and P limitation, and aminoacyl-tRNA synthetase scarcity under N limitation. Under these stresses, S. cerevisiae reallocates proteomic resources toward anabolic functions, with nutrient-specific phosphorylation networks compensating for translational stress, most pronounced under N limitation. Building on these insights, a "push-pull" strategy enhancing energy supply (VMA3) and translational capacity (WRS1) increased the maximal anaerobic growth rate by 27.2%, 47.5% and 52.5% under C, N, and P limitation, respectively. These findings reveal energy-translation coupling as the central determinant of anaerobic growth limits and provide a framework for rational strain engineering.