FIG. 3.

Degradation of xylose by recombinant Z. palmae under resting conditions. Strains harboring pMFY31 (A) or pMFY31-Pgap-xylA/xylB-Peno-tal/tktA (B) were cultured in T medium containing 20 g/liter glucose and 100 μg/ml ampicillin for 48 h at 30°C, after which harvested cells were resuspended in T medium containing 20 g/liter xylose to give a concentration of 8.2 mg (dry weight) of cells/ml. The time course of xylose degradation was determined by submitting aliquots of culture medium to high-performance liquid chromatography as described in Materials and Methods. Diamonds indicate residual xylose, and triangles indicate accumulated ethanol.