Prompt Description

A schematic diagram illustrating the glucose and acetate fermentation metabolic pathways of Saccharomyces cerevisiae. The core of the diagram presents carbon source conversion, the distribution of redox-related enzymes, and key metabolic cycles, clearly indicating native pathways, targeted modification sites, and heterologous enzyme integration locations. Core content displayed: Native metabolic pathways and enzymes (labeled in black): Clearly presents the core metabolic flow from glucose to ethanol, including key glycolytic enzymes such as hexokinase (HXK), phosphoglucose isomerase (PGI), and phosphofructokinase (PFK), as well as key ethanol-producing enzymes such as pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH). Native branching pathways for glycerol synthesis (GPD-related) and acetate production (ALD6-related) are also indicated. Targeted deleted enzymes (yellow ellipse + red "X" notation): Clearly marks the 4 enzymes knocked out via CRISPR-Cas9: NADH-dependent glycerol-3-phosphate dehydrogenase 1 (GPD1), cytoplasmic aldehyde dehydrogenase (ALD6), and mitochondrial external NADH dehydrogenases 1 (NDE1) and 2 (NDE2), visually demonstrating the targeted sites of gene editing. Heterologously expressed enzymes (labeled in red + yellow ellipse): Highlights the acetylating acetaldehyde dehydrogenase (SeEutE) introduced from Salmonella enterica, clarifying its role in the metabolic pathway and its association with acetyl-CoA conversion. Key metabolic cycles (highlighted with blue boxes): The "acetate futile cycle" is highlighted with blue boxes, clearly defining the scope of this cycle within the metabolic pathway and visually presenting the futile metabolic flow of acetaldehyde being oxidized to acetate via ALD6. The overall schematic diagram uses color differentiation and symbolic notation to accurately present the native metabolic network, gene modification targets, and the metabolic reprogramming logic after heterologous enzyme integration.