%0 Journal Article
%T The Production of Bioethanol from Cashew Apple Juice by Batch Fermentation Using Saccharomyces cerevisiae Y2084 and Vin13
%A Evanie Devi Deenanath
%A Karl Rumbold
%A Sunny Iyuke
%J ISRN Renewable Energy
%D 2013
%R 10.1155/2013/107851
%X Bioethanol as a fossil fuel additive to decrease environmental pollution and reduce the stress of the decline in crude oil availability is becoming increasingly popular. This study aimed to evaluate the concentration of bioethanol obtainable from fermenting cashew apple juice by the microorganism Saccharomyces cerevisiae Y2084 and Vin13. The fermentation conditions were as follows: initial sugar = 100£¿g/L, pH = 4.50, agitation = 150£¿rpm, temperatures = 30¡ãC (Y2084) and 20¡ãC (Vin13), oxygen saturation = 0% or 50%, and yeast inoculum concentration = ~8.00£¿Log£¿CFU/mL. The maximum ethanol concentration achieved by Y2084 was 65.00£¿g/L. At 50% oxygen the fermentation time was 5 days, whilst at 0% oxygen the fermentation time was 11 days for Y2084. The maximum ethanol concentration achieved by Vin13 was 68.00£¿g/L. This concentration was obtained at 50% oxygen, and the fermentation time was 2 days. At 0% oxygen, Vin13 produced 31.00£¿g/L of ethanol within 2 days. Both yeast strains produced a higher glycerol concentration at 0% oxygen. Yeast viability counts showed a decrease at 0% oxygen and an increase at 50% oxygen of both yeast stains. Other analyses included measurement of carbon dioxide and oxygen gases, process monitoring of the fermentation conditions, and total organic carbon. Gas analysis showed that carbon dioxide increased in conjunction with ethanol production and oxygen decreased. Process monitoring depicted changes and stability of fermentation parameters during the process. Total organic carbon analysis revealed that aerobic fermentation (50% oxygen) was a more efficient process as a higher carbon recovery (95%) was achieved. 1. Introduction The twenty-first century is plagued by difficulties like the decrease in resources of fossil fuel, rapid rise in greenhouse gas emissions contributing to global warming, and the lack of capability to meet the increasing energy demands. In trying to reduce the impact of these global concerns, bioethanol produced from renewable resources like biomass components has created significant interest. Bioethanol is a biofuel produced from biomass via biochemical procedures [1]. In general, bioethanol production is a three-stage process of: (i) hydrolysis, (ii) fermentation and (iii) distillation [2]. During hydrolysis, starch is converted from biomass feedstocks (cereal grains, lignocellulose, and macroalgae) into fermentable monosaccharide sugars [1¨C3]. Fermentation is a process which involves a sugar-rich substrate and a microorganism (MO) to bring about a chemical change in a closed aerobic or anaerobic atmosphere.
%U http://www.hindawi.com/journals/isrn.renewable.energy/2013/107851/