Effects of process errors on the production of ethanol by Escherichia coli KO11

摘要: KO11 was previously constructed for the production of ethanol from both hexose and pentose sugars in hemicellulose hydrolysates by inserting Zymomonas mobilis genes encoding pyruvate decarboxylase (pdc) alcohol dehydrogenase (adhB). This biocatalyst appears relatively resistant to potential process errors during fermentation. Antibiotics were not required maintain maximum catabolic activity even after deliberate contamination with up 10% soil. Fermentations exposed extremes temperature (2 h at 5°C or 50°C) pH 3 10) recovered re-adjustment optimal fermentation conditions (35°C, pH6) although longer times completion most cases. Ethanol yields altered exposure but reduced pH. Re-inoculation 5% (by volume) control fermentors this delay extremes.