Evaluation of Cashew Apple Juice for the Production of Fuel Ethanol

Abstract

A commercial strain of Saccharomyces cerevisiae was used for the production of ethanol by fermentation of cashew apple juice. Growth kinetics and ethanol productivity were calculated for batch fermentation with different initial sugar (glucose + fructose) concentrations. Maximal ethanol, cell, and glycerol concentrations were obtained when 103.1 g L⁻¹ of initial sugar concentration was used. Cell yield (Y _X/S) was calculated as 0.24 (g microorganism)/(g glucose + fructose) using cashew apple juice medium with 41.3 g L⁻¹ of initial sugar concentration. Glucose was exhausted first, followed by fructose. Furthermore, the initial concentration of sugars did not influence ethanol selectivity. These results indicate that cashew apple juice is a suitable substrate for yeast growth and ethanol production.

Appendix

Ks:

substrate saturation parameter (g L⁻¹)

P _max :

product concentration when cell growth ceases (g L⁻¹)

S :

substrate concentration (g L⁻¹)

X :

biomass concentration (g L⁻¹)

X _max :

biomass concentration when cell growth ceases (g L⁻¹)

Y _P/X :

yield of product based on cell growth (g/g)

Y _X/S :

yield of cell growth based on substrate consumptions (g/g)

Y _P/S :

yield of product based on substrate consumptions (g/g)

C _em :

maximum ethanol concentration (g L⁻¹)

μ _max :

maximum specific growth rate (h⁻¹)

μ _p :

specific rate of product formation (g/[L.h])

μ _S :

specific rate of substrate consumption (g/[L.h])

μ _x :

specific rate of growth (g/[L.h])