OPTIMIZING THE PRODUCTION OF BIO-ETHANOL FROM Prosopis juliflora LEAVES USING Saccharomyces cerevisiae

Abstract

Production of bio-ethanol from Lingocellulosic materials is naturally abundunt renewable resources that can potentially provide a long-term sustainable fuel supply. Prosopis juliflora, an invasive plant is one source of lignocellosic materials to serve as feedstock for bio-ethanol production. With the objective of evaluating its potential for bio-ethanol production, differen concentrations (10g, 20g, 30g, and 40g) of P. juliflora leaves treated with dilute sulfuric acid and untreated were incubated for fermentation over 20 days with 0.5 or 1% yeast (Saccharomyces cerviceae) inoculums. Percent bio-ethanol, cell density and amount or reducing sugars were measured at an interval of 4 days starting from the begining of fermentation. Results showed that ethanol production was observed starting from the 4th day of fermentation, but its amount peaked 29.05% from 40g substration with 1% inoculum on the 12th day of fermentation, and declined afterwards on 16th&20thdays of fermentation(19.25% &16.38%) respectively at the same substrate concentration. In agreement with ethanol production, cell density and reduction in reducing sugar were observed in the same pattern. Compared ethanol production between untreated substrates yieled of 25.35%, and acid pre-treated substrates yielded of 29.05% then acid pretreated showed significantlly higher ethanol production than untreated at the same substration concentration of 40gram inoculated with 1% yeast cell. Overall, this study showed that acid pre-treatment, inoculum concentration, fermentation period and substrate concentration affect the amount of bio-ethanol production