Estimation of kinetic and yield parameters: ethanol fermentation of a glucose and fructose mixture using Zymomonas mobilis

Abstract

A new method is presented to calculate the kinetic and yield parameters of a fermentation. This method is based on polynomial fitting of the variations of substrates and biomass concentrations with time and calculation of instantaneous and overall parameters. Application to a mixed substrate and mixed product fermentation by the bacterium Zymomonas mobilis is presented.

Fermentation of Soybean Meal Hydrolyzates with Saccharomyces cerevisiae and Zymomonas mobilis for Ethanol Production

“…The biomass yield from substrate (Yx/s) listed in Table was significantly higher ( P = 0.05) for S. cerevisiae (0.1 g cell/g sugar consumed) than Z. mobilis (0.08 g cell/ g sugar consumed) when fermenting the SBMB1. Higher values with S. cerevisiae than Z. mobilis have also been reported by other researchers (Dien and others , Aitabdelkader and Baratti ). This is a function of the better resistance of the yeast to the inhibitors present in these substrates (Weber and others ).…”

Isolation and Properties of Mutants of Zymomonas mobilis Deficient in Sugar Assimilation

“…Growth on a glucose-fructose equimolar mixture represents a good model for the growth of Z. mobilis on sucrose (1,9). The specific growth rates of the fructose-negative mutants on this mixed carbon source were similar to that of ZM4.…”

Modelling of ethanol production by Saccharomyces cerevisiae from a glucose and maltose mixture

“…A number of possible substrates for mass production of ethanol have been reported: corn residue prehydrolysate, sugar beet molasses, sugar cane molasses, Jerusalem artichoke juice, cellulose, naked barley, and cassava (Lawford and Rousseau, 1992;Park and Baratti, 1992;Limtong et al, 1987;Favela-Torres et al, 1985;Tyagi andGhose, 1980: Philippidis et al, 1993;Nam et al, 1992). Also artificial mixed substrates such as glucose-xylose mixture, glucosefructose mixture, and glucose-galactose mixture were studied recently (Beck et al, 1990;Grootjen et al, 1991;Laplace et al, 1991;Ait-Abdelkader and Baratti, 1993). We have been developing a continuous ethanol fermentation process using tapioca as the starch source.…”