Premium
Production of recombinant bacterial endoglucanase as a co‐product with ethanol during fermentation using derivatives of Escherichia coli KO11
Author(s) -
Wood B. E.,
Beall D. S.,
Ingram L. O.
Publication year - 1997
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(19970805)55:3<547::aid-bit12>3.0.co;2-d
Subject(s) - cellulase , fermentation , klebsiella oxytoca , cellulose , chemistry , biochemistry , lysis , ethanol fermentation , escherichia coli , food science , enterobacteriaceae , gene
This study demonstrates a new approach to reduce the amount of fungal cellulase required for the conversion of cellulose into ethanol. Escherichia coli KO11, a biocatalyst developed for the fermentation of hemicellulose syrups, was used to produce recombinant endoglucanase as a co‐product with ethanol. Seven different bacterial genes were expressed from plasmids in KO11. All produced cell‐associated endoglucanase activity. KO11(pLOI1620) containing Erwinia chrysanthemi celZ (EGZ) produced the highest activity, 3,200 IU endoglucanase/L fermentation broth (assayed at pH 5.2 and 35°C). Recombinant EGZ was solubilized from harvested cells by treatment with dilute sodium dodecyl sulfate (12.5 mg/ml, 10 min, 50°C) and tested in fermentation experiments with commercial fungal cellulase (5 filter paper units/g cellulose) and purified cellulose (100 g/L). Using Klebsiella oxytoca P2 as the biocatalyst, fermentations supplemented with EGZ as a detergent‐lysate of KO11(pLOI1620) produced 14%–24% more ethanol than control fermentations supplemented with a detergent‐lysate of KO11(pUC18). These results demonstrate that recombinant bacterial endoglucanase can function with fungal cellulase to increase ethanol yield during the simultaneous saccharification and fermentation of cellulose. © 1997 Wiley & Sons, Inc. Biotechnol Bioeng 55 : 547–555, 1997.