Production the industrial levels of bioethanol from glycerol by engineered yeast "Bioethanol-4th generation"

Besides the pledges for expanding uses of biofuels to sustain the humanosphere, abruptly massive needs emerged for sanitizers with turns COVID-19 to a pandemic. Therefore, ethanol is topping the social-demanding, although the three generations of production, from molasses/starch, lignocelluloses, and algae. Owing to the limited-availability of fermentable sugars from these resources, we addressed glycerol as a fourth bio-based carbon resource from biodiesel, soap, and fatty acid industries, which considers as a non-applicable source for bioethanol production. Here, we show the full strategy to generate efficient glycerol fermenting yeast by innovative rewriting the oxidation of cytosolic nicotinamide-adenine-dinucleotide (NADH) by O2-dependent dynamic shuttle while abolishing glycerol biosynthesis route. Besides, imposing a vigorous glycerol-oxidative pathway, the engineered strain demonstrated a breakthrough in conversion efficiency (up to 98%). Its capacity extending to produce up to 90g /l ethanol and > 2 g 1-1 h-1, which promoting the industrial view. Visionary metabolic engineering here provides horizons for further tremendous economic and health benefits with assuring for its enhancing for the other scenarios of biorefineries. SummaryEfficiently fermenting glycerol in yeast was developed by comprehensive engineering the glycerol pathways and rewriting NADH pathways.