Abstract
Kluyveromyces marxianus DMKU 3-1042, isolated by an enrichment technique in a sugar cane juice medium supplemented with 4%
(w/v) ethanol at 35 C, produced high concentrations of ethanol at both 40 and 45 C. Ethanol production by this strain in shaking flask
cultivation in sugar cane juice media at 37 C was highest in a medium containing 22% total sugars, 0.05% (NH4)2SO4, 0.05% KH2PO4,
and 0.15% MgSO4 Æ 7H2O and having a pH of 5.0; the ethanol concentration reached 8.7% (w/v), productivity 1.45 g/l/h and yield 77.5%
of theoretical yield. At 40 C, a maximal ethanol concentration of 6.78% (w/v), a productivity of 1.13 and a yield 60.4% of theoretical
yield were obtained from the same medium, except that the pH was adjusted to 5.5. In a study on ethanol production in a 5 l jar fermenter
with an agitation speed of 300 rpm and an aeration rate of 0.2 vvm throughout the fermentation, K. marxianus DMKU
3-1042 yielded a final ethanol concentration of 6.43% (w/v), a productivity of 1.3 g/l/h and a yield of 57.1% of theoretical yield.
2007 Elsevier Ltd. All rights reserved.