Iterative dissolved-oxygen control combined with growth-production coordination enables efficient erythritol...

A comprehensive understanding of the growth-production trade-off under heat stress is essential for developing high-yield thermotolerant chassis. Here, the effects of elevated temperature on growth and erythritol biosynthesis were systematically investigated in YL (A high-erythritol-producing industrial Yarrowia lipolytica strain). Notably, a heat-induced abnormal growth-surge effect (AGSE) was observed and identified, in which high dissolved oxygen conditions were associated with altered ATP-related metabolic activity, oxidative stress responses, and increased accumulation of stress-protective metabolites. Based on this, iterative dissolved-oxygen optimization under high-temperature conditions enabled the development of a robust erythritol-producing chassis, YL-EV-18-G5, which exhibited stable growth at 35°C with erythritol yield of 0.526 g/g glucose. Further, a hybrid erythritol-responsive bidirectional promoter (P_{ery-BidR (5AB)}) was applied for random genomic integration, thereby coupling erythritol synthesis with the expression of growth-related genes, yielded a growth-production-coordinated strain, YL-EV-18-G5-GPcEs4-F12 (F12). Compared with parental strain YL, F12 exhibited a 179.3% increase in erythritol titer, reaching a maximum concentration of 225.50 g/L, and the yield increased by 35.34% to 0.656 g/g glucose. Mechanistically, the high productivity of F12 is associated with optimized stress-protective metabolite synthesis, reduced single-cell erythritol production heterogeneity, and adaptive genomic changes accumulated during evolutionary engineering. These findings advance the understanding of thermotolerance in oleaginous yeasts and provide a potential strategy for engineering heat-resistant microbial cell factories.