Fig. 3
From: Systematic improvement of isobutanol production from d-xylose in engineered Saccharomyces cerevisiae
Growth profile and isobutanol production of engineered strains in selective medium containing 2% xylose. Growth profiles of engineered strains expressing XR–XDH from S. stipitis (a) and C. tropicalis (b). Total (c) and specific (e) isobutanol production after 2 days of engineered strains expressing XR–XDH from S. stipitis. Total (d) and specific (f) isobutanol production after 2 days of engineered strains expressing XR–XDH from C. tropicalis. Engineered strains were pre-cultured in 5-mL aliquots in SD selective medium overnight and used to inoculate 10 mL fresh SX (2% xylose) to achieve an initial optical density of 0.05 at 600 nm (OD600). The cultures were grown at 30 °C and 250 rpm in an orbital shaking incubator. Samples were taken after 2 days and the supernatants were analyzed on HPLC to quantify the isobutanol content. Values are the mean of three biological replicates ± standard deviation (n = 3). N.D. represents not detected due to strain’s inability to grow. Ll, Lactococcus lactis; Sc, Saccharomyces cerevisiae; Ss, Scheffersomyces stipitis; Ct, Candida tropicalis