Effect of <i>Sacoglottis gabonensis</i> and <i>Alstonia boonei</i> on the kinetics of <i>Saccharomyces cerevisiae</i> isolated from palm wine

Abstract

Sacoglottis gabonensis and Alstonia boonei are botanicals used for the preservation of palm wine in Southern Nigeria. This study investigated the effect of S. gabonensis (0.625%) and A. boonei (0.50%) on the kinetics of Saccharomyces cerevisiae isolated from palm wine (PW). Concentrations of the preservatives used in this study were optimal concentrations of the preservatives that had preservative effect on fermenting palm sap. The fermentation rate constant, k, of 2.79 × 10^-4 mol^-1 s^-1 obtained for untreated PW was higher than the k values for PW treated with A. boonei (1.7 × 10^-4 mol^-1 s^-1) and S. gabonensis (1.1 × 10^-4 mol^-1 sec^-1). Both preservatives enhanced yeast growth. The specific growth rates (μmax) for the yeast were 0.43, 0.76 and 0.88 for the control, samples treated with A. boonei and S. gabonensis, respectively. However, the sedimentation rate of the yeast was reduced by both preservatives, but A. boonei produced the greatest effect. The utilization of these botanicals for industrial fermentations involving yeast is promising.

Keywords: Palm wine, preservation, Saccharomyces cerevisiae, fermentation kinetic, growth kinetic, sedimentation rate, Sacoglottis gabonensis, Alstonia boonei

African Journal of Biotechnology Vol. 9(35), pp. 5730-5734, 30 August, 2010