Utilization of corn cob acid hydrolysate by gTME recombinant Saccharomyces Cerevisiae
The recombinant Saccharomyces Cerevisiae YPH499-3, which could highly utilize xylose and coferment xylose and glucose, was obtained using the gTME(global transcription machinery engineering) to restructure and improve the phenotype of Saccharomyces Cerevisiae. The maximum xylose and glucose yield were 38.95 g/L and 4.85 g/L, respectively, with the pretreatment of corn cob under the condition as follows: 120 ℃, solid/liquid of 1:10(m/v), 3% HCl autoclaved for 2 hours. The gTME recombinant Saccharomyces Cerevisiae YPH499 -3 and the control strain Saccharomyces Cerevisiae YPH499 were inoculated in the 100 mL shaking flask containing 50 mL acid hydrolysate with different initial pH for anaerobic fermentation. The results showed that YPH499-3 grew more rapidly and had higher sugar utilization and ethanol yield, comparison to YPH499. YPH499 -3 reached the maximum xylose and glucose utilization of 65.7% and 86.6%, respectively, meantime the maximum ethanol concentration was 8.90 g/L,after 71 hours in the acid hydrolysate with the initial pH 5. YPH499 reached the maximum glucose utilization and ethanol yield of 67.4% and 2.38 g/L, respectively, after 71 hours in the acid hydrolysate with the initial pH 5.