Micro guard carbo c guard column

Example 14

Cells aerobically grown overnight on YNB medium supplemented with 20 g/L glucose were used to inoculate a serum flask containing 30 mL of YNB medium supplemented with glucose (20 g/L) and xylose (50 g/L) as carbon source and acetic acid (8 g/L) at initial concentration of 1 g cell dry weight/L.

Concentrations of glucose, xylose, ethanol, glycerol, xylitol and acetic acid were determined by high performance liquid chromatography (Waters, Milford, Mass., USA). The compounds were separated with a Shodex SUGAR SP0810 Pb2+ copolymer-based column (Showa Denko America, NY, USA), or a Rezex H+ column, preceded by a Micro-Guard Carbo-C guard column (Bio-Rad, Hercules, Calif., USA). Separation was performed at 80° C., with H2O at a flow rate of 0.6 ml min-1 as mobile phase. Compounds were quantified by refractive index detection (Waters). A seven-point calibration curve was made for each compound to calculate concentrations.

Results are presented graphically in FIG. 10, FIG. 11, and FIG. 12. In conclusion, more xylose was consumed, and more ethanol was produced, in strain C5LTe1212 expressing the YME2 gene.

Example 27

Cells aerobically grown overnight on YNB medium supplemented with 20 g/L glucose were used to inoculate a serum flask containing 30 mL of YNB medium supplemented with glucose (20 g/L) and xylose (50 g/L) as carbon source and formic acid (4.5 g/L) at initial concentration of 1 g CDW/L.

Concentrations of glucose, xylose, ethanol, glycerol, and xylitol were determined by high performance liquid chromatography (Waters, Milford, Mass., USA). The compounds were separated with a Shodex SUGAR SP0810 Pb2+ copolymer-based column (Showa Denko America, NY, USA) preceded by a Micro-Guard Carbo-C guard column (Bio-Rad, Hercules, Calif., USA). Separation was performed at 80° C., with H2O at a flow rate of 0.6 ml min-1 as mobile phase. Compounds were quantified by refractive index detection (Waters). A seven-point calibration curve was made for each compound to calculate concentrations. Results are presented graphically in FIG. 25 (xylose consumption) and FIG. 26 (ethanol production) as well as in Table 4.

In conclusion, these data show that strains carrying PGM1 or PGM3 consumed more xylose and produced more ethanol than the control strain.