Collect. Czech. Chem. Commun. 1989, 54, 1244-1256

The ingfluence of temperature, pH and aeration on the ethanolic fermentation of glucose by Pachysolen tannophilus

F. Camacho Rubioa, V. Bravo Rodrígueza, S. Sánchez Villasclarasb and M. Castro Vicob

a Departamento de Ingenieria Quimica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
b Departamento de Ingenieria Quimica, Colegio Universitario, Universidad de Granada, 23071 Jaen, Spain


The ethanolic fermentation of 25 g l-1 solutions of glucose in batch cultures of Pachysolen tannophilus has been studied experimentally in terms of three environmental variables: initial pH from 1.5 to 6.5, temperatures of 25 °C, 30 °C and 35 °C and aeration values of Q = 0.150 v/v/min, Q = 0.075 v/v/min and Q = 0 v/v/min (i.e. with air entering through the stirring vortex alone). Using the values for the concentrations of biomass, residual glucose and ethanol produced at intervals throughout the experiments, the maximum specific rates of growth, glucose consumption and ethanol production, together with the biomass and ethanol yields, have been calculated. The most favourable conditions for ethanol production are an initial pH of about 3, temperature of 30 °C and Q = 0 v/v/min. Under these conditions the ethanol yield is approximately 0.36 (g ethanol) (g glucose)-1 and the maximum specific production rate is 1.2 (g ethanol) (g biomass)-1 h-1.