The feasibility of producing ethanol in a continuous system from cellulose using Clostridirrrn thermocellum was investigated. This anaerobic and therniophilic bacterium was able to degrade cellulose directly into ethanol with acetic acid, hydrogen. and carbon dioxide as by-products of this fermentation. The fermentation was first carried out in a batch mode to study the effects of buffers, temperature, and agitation on microbial growth and ethanol production. From the compounds used to control pH. sodium bicarbonate had the most preferred effects on generation time and ethanol production. As expected, there was a positive relationship between temperature and growth rate. On the other hand, agitation did not benefit from ethanol production or microbial growth. The possibility of noncompetitive inhibition within such a system was deduced from the calculation of the kinetic constants K(m) and V(max). Continuous fermentations were carried out at 60 degrees C and pH 7.0 using 1.5 and 3% pure cellulose as a limiting substrate. The maximum ethanol concentration reached during the 1.5% cellulose fermentation was 0.3%. and 0.9% during the 3% cellulose fermentation. The yield of ethanol was about 0.3 grams per gram of consumed cellulose. The overall yield in both schemes was around 0.45 and 0.75 grams per gram of cellulose degraded. It was concluded that cellulose could be degraded continuously in a system with C. thermocellum for production of ethanol. While the continuous system like the batch method is feasible, it may not be promising as yet because of the slow generation time of this microorganism.
This study was undertaken with the major goal of optimizing the ethanol production from whey using computer technology. To reach this goal, a mathematical model that would describe the fermentation and that could be used for the optimization was developed. Kluyveromyces fragilis was the microorganism used to ferment the lactose in the whey into ethanol. Preliminary studies showed that K. fragilis produced about 90% of the theoretical ethanol yield when grown in whey-complemented media. However, when this yeast is grown in nonsupplemented whey media, it does not produce more than 32% of that yield. Comparative batch fermentations of lactose and whey-complemented media showed that whey possibly contains enhancing components for yeast growth and ethanol production. To obtain the mathematical model, the one-to-one effect of the process variables (lactose and yeast extract concentrations, air flowrate, pH, and dilution rate) on the ethanol production were first investigated. Experiments on the pH effect showed that a decrease in pH from 7 to 4 produced an increase in ethanol concentration from 16.5 to 26.5 g/L (50 g/L initial lactose). The results obtained from modeling of the continuous fermentation using the previously listed variables showed that air flowrate, pH, and dilution rate were the process variables that most influence the production of ethanol.
The mobile device industry has changed dramatically over the last 10 years. The world is swiftly adopting mobile devices, and Apple and Google have become major players in an industry that now encompasses a burgeoning mobile-fashion marketing business. This research project sought to help apparel retailers understand more about apparel consumers’ usage of mobile devices and perceptions of mobile marketing strategies, and to shed light on better business practices. The study used a quantitative research method, along with cross-sectional, descriptive, and non-probabilistic sampling techniques. An online questionnaire survey was designed to collect data with a sample of 390 mobile device users in the Greater Toronto Area. SPSS was used for coding and analyzing the information.
Clostridium thermocellum was used to produce ethanol from cellulose in a continuous system: Batch fermentations were first performed to observe the effects of buffers and agitation on generation time and ethanol production. Continuous fermentations were carried out at 60°C and pH 7 using pure cellulose as the limiting substrate. The maximum ethanol concentrations produced with 1.5 and 3% cellulose fermenting liquid were 0.3 and 0.9% respectively.
The mobile device industry has changed dramatically over the last 10 years. The world is swiftly adopting mobile devices, and Apple and Google have become major players in an industry that now encompasses a burgeoning mobile-fashion marketing business. This research project sought to help apparel retailers understand more about apparel consumers’ usage of mobile devices and perceptions of mobile marketing strategies, and to shed light on better business practices. The study used a quantitative research method, along with cross-sectional, descriptive, and non-probabilistic sampling techniques. An online questionnaire survey was designed to collect data with a sample of 390 mobile device users in the Greater Toronto Area. SPSS was used for coding and analyzing the information.
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