PRODUCTION OF ETHANOL BY FED-BATCH FERMENTATION

The production of ethanol, from glucose in batch and fed batch culture, was investigated. In the fed batch culture, the glucose feeding was added into the culture at 16th hour of fermentation. The effects of different glucose concentration feeding rates on ethanol fermentation were investigated for fed batch culture. The 2gL-1hr-1 glucose concentration feeding rate was found to give higher ethanol yield (2.47 g ethanol g glucose-1), with respect to substrate consumed as compared to 8 gL-1hr-1 (0.23 g ethanol g glucose-1) and 4 gL-1hr-1 (0.20 g ethanol g glucose-1). The ethanol yield with respect to substrate consumed obtained in batch culture was 0.81 g ethanol g glucose-1. The fed batch culture at 2 gL-1hr-1 glucose concentration feeding rate was proven to be a better fermentation system than the batch culture. The specific growth rate, specific glucose consumption rate and specific ethanol production rate for the fed batch fermentation, at 2 gL-1hr-1 glucose concentration feeding rate, were 0.065 hr-1, 1.20 hr-1 and 0.0009 hr-1, respectively

Model of Continuous Cheese Whey Fermentation by Candida Pseudotropicalis

The utilization of cheese whey as a fermentation substrate to produce bio-ethanol is an effort to supply bio-ethanol demand as a renewable energy. Like other process systems, modeling is also required for fermentation process design, optimization and plant operation. This research aims to study the fermentation process of cheese whey by applying mathematics and fundamental concept in chemical engineering, and to investigate the characteristic of the cheese whey fermentation process. Steady state simulation results for inlet substrate concentration of 50, 100 and 150 g/l, and various values of hydraulic retention time, showed that the ethanol productivity maximum values were 0.1091, 0.3163 and 0.5639 g/l.h respectively. Those values were achieved at hydraulic retention time of 20 hours, which was the minimum value used in this modeling. This showed that operating reactor at low hydraulic retention time was favorable. Model of bio-ethanol production from cheese whey will enhance the understanding of what really happen in the fermentation process

Ethanol-water separation by pervaporation

The separation of ethanol-water mixtures is of great importance for the production of ethanol from biomass. Both ultrafiltration and pervaporation processes can be used for the continuous processing of fermentation and separation, The removal of ethanol from the ultrafiltration permeate can be accomplished by pervaporation. Separation of ethanol-water mixtures by the pervaporation process has been investigated. Results are presented for membranes which are preferentially permeable for ethanol and for others which are preferentially water permeable. Details on the preparation of several membrane types (homogeneous, asymmetric and composite) are given. A schematic process diagram is given in which the fermentation of sugars to ethanol is membrane-controlled

Integrative Investment Appraisal of a Lignocellulosic Biomass-to-Ethanol Industry

While theoretically more efficient than starch-based ethanol production systems, conversion of lignocellulosic biomass to ethanol is not without major challenges. A multi-region, multi-period, mixed integer mathematical programming model encompassing alternative feedstocks, feedstock production, delivery, and processing is developed. The model is used to identify key cost components and potential bottlenecks, and to reveal opportunities for reducing costs and prioritizing research. The research objective was to determine for specific regions in Oklahoma the most economical source of lignocellulosic biomass, timing of harvest and storage, inventory management, biorefinery size, and biorefinery location, as well as the breakeven price of ethanol, for a gasification-fermentation process. Given base assumptions, gasification-fermentation of lignocellulosic biomass to ethanol may be more economical than fermentation of corn grain. However, relative to conventional fermentation processes, gasification-fermentation technology is in its infancy. It remains to be seen if the technology will be technically feasible on a commercial scale.biomass, biorefinery location, ethanol, integrative investment appraisal, logistics, mixed integer programming, Resource /Energy Economics and Policy,

Improved production of ethanol using bagasse from different sorghum cultivars

For improved production of ethanol from whole sorghum residues, physico-chemical compositions and fermentation characteristics of the substrates are important factors to consider. In the present study, Nigerian sorghum cultivars SSV2, KSV8 and KSV3 were grown under rain-fed conditions without chemical fertilization in Kano state, Nigeria. On harvest, the whole sorghum residues (bagasse) comprising crushed stalks, leaves, panicles and peduncles were collected for further processing. Bagasse samples, which had different macromolecular composition and carbohydrate pasting properties, were pre-treated with dilute sulphuric acid at 75 °C followed by enzymatic hydrolysis and sequential detoxification by Ca(OH)2 over-liming and charcoal filtration. Hydrolysate samples were subsequently fermented with the yeasts, Saccharomyces cerevisiae and Pachysolen tannophilus. Sugar consumption, carbon dioxide evolution and ethanol production were shown to vary depending on the sorghum cultivar type. While KSV3 yielded most favourable biomass of 37 t ha−1 (dry basis), bagasse from cultivar SSV2 yielded the most favourable level of sugars (69 g/100 g) after enzymatic hydrolysis, and also consistently exhibited improved fermentation performance. Detoxification of pre-treated sorghum bagasse to remove potential yeast inhibitors resulted in improvement in ethanol yield, with 23 g L−1 ethanol (representing 72% of theoretical yield) being achieved from SSV2 bagasse following fermentation with P. tannophilus without exogenous nutrient supplementation. Our findings reveal that the choice of sorghum cultivar is important when converting bagasse to ethanol, and further that pretreatment with dilute acid at moderate temperature followed by detoxification improves fermentation kinetics and ethanol yield

Activity of Zymomonas mobilis on ethanol products made of cashew nut apple (Anacardium occidentale) with different sources of nitrogen

Mustofa A, Suranto. 2009. Activity of Zymomonas mobilis on ethanol production made of cashew nut apple (Anacardium occidentale) with different sources of nitrogen. Nusantara Bioscience 1: 105-109. This research is aimed at identifying Zymomonas mobilis in producing ethanol through batch fermentation process (in 24, 48 and 72 hours) using cashewnut apple extract (red, green and yellow variety) and urea, ammonium sulphate, extract of green peanut sprout and extract koro (Mucuna pruriens) as sources of nitrogen. The research showed that green cashewnut extract with ammonium sulphate in 24 hours of fermentation produced ethanol in optimum result. This treatment had pH of 5.87, 7.64 g/100 mL of sugar (with 48.44% of consumption), 8.0x10 7 amount of bacterium (µ = 0.154) and production of ethanol equal to 33.02 g/L (Ye = 90.19%). Key words: Zymomonas mobilis, cashewnut apple extract, ethanol

Making Ethanol from Tapioca Starch Liquid Waste by Hydrolysis and Fermentation

Alcohol or often called ethanol (ethyl alcohol) in the industrialized world which is often used as a solvent, can be produced by fermentation using the yeast Saccharomyces Cereviceae. The basic ingredients that can be fermented include materials that contain saccharin, starch, and selullosa. Production of ethanol in this study carried out by using the basic ingredients of starch derived from tapioca starch liquid waste that has a starch content of 8.14%. Before the fermentation process, first performed by the process of hydrolysis using bacteria producing enzyme α- amylase is Bacillus to obtain a solution containing sugar (glucose). Result of hydrolysis solution containing glucose at 4.82%, 5.3% and 5.7% then fermented for a certain time interval by using yeast Saccharomyces Cereviceae. From the experimental results obtained a conclusion that maximum results are obtained occurs in 10% bacillus fermentation lasts for 15 days with levels of ethanol produced by 20.14%

Isolation and characterisation of Sri Lankan yeast germplasm and its evaluation for alcohol production

Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in Sri Lankan alcohol distilleries that use sugarcane molasses. The present study isolated and characterised yeast strains found in natural environments in Sri Lanka and evaluated their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Yeasts were characterised based on morphological and physiological features such as sugar fermentation and nitrate assimilation. Ethanol production, alcohol tolerance and growth rate of the most promising strains were monitored following laboratory fermentations of molasses. Over a thousand yeast cultures were collected and screened for fermentative activity and a total of 83 yeast isolates were characterised as higher ethanol producers. Most of these belonged to the genus Saccharomyces. Certain strains produced over 10% (v/v) alcohol in molasses media during 72 h laboratory fermentations. Only two strains, SL-SRI-C-102 and 111, showed an appreciable fermentation efficiency of about 90%. The latter strain produced the highest level of ethanol, 11% (v/v) within a 48 h fermentation and exhibited improved alcohol tolerance when compared with the baker's yeast strains currently used in Sri Lankan alcohol distilleries. This study highlights the benefits of exploiting indigenous yeasts for industrial fermentation processes

接合によりグルコアミラーゼ遺伝子STA1が発現したビール酵母の育種

Standard brewing yeast cannot utilize larger oligomers or dextrins, which represent about 25% of wort sugars. A brewing yeast strain that could ferment these additional sugars to ethanol would be useful for producing low-carbohydrate diabetic or low-calorie beers. In this study, a brewing yeast strain that secretes glucoamylase was constructed by mating. The resulting Saccharomyces cerevisiae 278/113371 yeast was MATa/ diploid, but expressed the glucoamylase gene STA1. At the early phase of the fermentation test in malt extract medium, the fermentation rate of the diploid STA1 strain was slower than those of both the parent strain S. cerevisiae MAFF113371 and the reference strain bottom-fermenting yeast Weihenstephan 34/70. At the later phase of the fermentation test, however, the fermentation rate of the STA1 yeast strain was faster than those of the other strains. The concentration of ethanol in the culture supernatant of the STA1 yeast strain after the fermentation test was higher than those of the others. The concentration of all maltooligosaccharides in the culture supernatant of the STA1 yeast strain after the fermentation test was lower than those of the parent and reference strains, whereas the concentrations of flavor compounds in the culture supernatant were higher. These effects are due to the glucoamylase secreted by the constructed STA1 yeast strain. In summary, a glucoamylase-secreting diploid yeast has been constructed by mating that will be useful for producing novel types of beer owing to its different fermentation pattern and concentrations of ethanol and flavor compound

Preparation of Wine from Jackfruit (Artocarpus heterophyllus lam)Juice Using Baker yeast: Effect of Yeast and Initial Sugar Concentrations

The overproduction of jackfruit (Artocarpus heterophyllus Lam) during harvest season and its short shelf-life have caused serious losses for farmers. Fortunately, high sugar content of the fruit pulp makes the juice a potential substrate for wine production. This work was purposed to investigate the effect of yeast and initial sugar concentrations on jackfruit juice wine fermentation. Clarified jackfruit juice of 14 % w/w sugar concentration was fermented using 0.5 to 2.0 % w/v Baker’s yeast (Saccharomyces cerevisiae) under anaerobic condition at 30°C for 14 days. Samples were collected daily for ethanol and sugar contents analysis. The profile of sugar and ethanol concentration as function of fermentation time, showed that higher yeast inoculums rate and initial sugar concentrations inhibited growth of yeasts. The fermentation of original jackfruit juice of 14 % w/w sugar concentration using 0.5% w/v yeast for 9 days was the best to produce a good quality wine with 12.13% v/v of ethanol and specific jackfruit aroma