Cellulosic Ethanol Production Using a Dual Functional Novel Yeast

Figure 3

A schematic illustration of significant gene expression changes for the genetically engineered Saccharomyces cerevisiae NRRL Y-50463 compared with its parental wild-type industrial strain NRRL Y-12632 for endogenous genes involved in glycolysis, pentose phosphate pathway, and TCA cycle at 24 h using xylose as the sole source of carbon when glucose was depleted. The arrows on the left and the top from the parallel lines represent aerobic growth condition and those on the right side or at the bottom represent oxygen-limited fermentation condition. The blue- or green-colored arrows indicate significantly greater gene expression for aerobic and oxygen-limited conditions, respectively. The arrows in red indicate repressed expression, and the arrows in black indicate gene expression at normal or nearly normal levels. Elements of the signature expression for strain NRRL Y-50463 were boxed in various colors and labeled I, II, and III (A). An illustration of xylose transformation and metabolism through the nonoxidative pentose phosphate pathway for the genetically engineered industrial yeast Saccharomyces cerevisiae NRRL Y-50463. 2C-A stands for acetaldehyde; 3C-G, glyceraldehydes 3-phosphate; 3C-P, pyruvate; 4C, erythrose 4-phosphate; 5C-R, ribose 5-phosphate; 5C-X, xylulose 5-phosphate; 6C-F, fructose 6-phosphate; 6C-G, glucose 6-phosphate; and 7C, sedoheptulose 7-phosphate. Expression fold changes against the wild-type control at 24 h are presented in green (B) [56].