Evaluation of a recombinant Klebsiella oxytoca strain for ethanol production from cellulose by simultaneous saccharification and fermentation: comparison with native cellobiose-utilising yeast strains and performance in co-culture with thermotolerant yeast and Zymomonas mobilis

Abstract

In the simultaneous saccharification and fermentation to ethanol of 100 g l(-1) microcrystalline cellulose, the cellobiose-fermenting recombinant Klebsiella oxytoca P2 outperformed a range of cellobiose-fermenting yeasts used in earlier work, despite producing less ethanol than reported earlier for this organism under similar conditions. The time taken by K. oxytoca P2 to produce up to about 33 g l(-1) ethanol was much less than for any other organism investigated, including ethanol-tolerant strains of Saccharomyces pastorianus, Kluyveromyces marxianus and Zymomonas mobilis. Ultimately, it produced slightly less ethanol (maximum 36 g l(-1)) than these organisms, reflecting its lower ethanol ..