17 resultados para Fermentation media
Resumo:
A study has been conducted focusing on how the phosphorus renrx)val efficiency of a constructed wetland (CW) can be optimized through the selective enrichment of the substratum. Activated alumina and powdered iron were examined as possible enrichment compounds. Using packed glass column trials it was found that alumina was not suitable for the renx)val of ortho-phosphate from solution, while mixtures of powdered iron and quartz sand proved to be very efficient. The evaluation of iron/sand mixtures in CWs planted with cattails was performed in three stages; first using an indoor lab scale wetland, then an outdoor lab scale wetland, and finally in a small scale pilot project. For the lab scale tests, three basic configurations were evaluated: using the iron/sand as a pre-filter, in the root bed. and as a post filter. Primary lagoon effluent was applied to the test cells to simulate actual CW conditions, and the total phosphorus and iron concentrations of the influent and effluent were nfK)nitored. The pilot scale trials were limited to using only a post filter design, due to in-progress research at the pilot site. The lab scale tests achieved average renrK>val efficiencies greater than 91% for all indoor configurations, and greater than 97% for all outdoor configurations. The pilot scale tests had an average renK)val efficiency of 60%. This relatively low efficiency in the pilot scale can be attributed to the post filters being only one tenth the size of the lab scale test in terms of hydraulic loading (6 cm/day vs. 60 cm/day).
Resumo:
The maximum amount of ethyl carbamate (EC), a known animal carcinogen produced by the reaction of urea and ethanol, allowed in alcoholic beverages is regulated by legislation in many countries. Wine yeast produce urea by the metabolism of arginine, the predominant assimilable amino acid in must. This action is due to arginase (encoded by CARl). Regulation of CARl, and other genes in this pathway, is often attributed to a well-documented phenomenon known as nitrogen catabolite repression. The effect of the timing of di-ammonium phosphate (DAP) additions on the nitrogen utilization, regulation of CARl, and EC production was investigated. A correlation was found between the timing of DAP addition and the utilization of nitrogen. When DAP was added earlier in the fermentations, less amino nitrogen and more ammonia nitrogen was sequestered from the media by the cells. It was also seen that early DAP addition led to more total nitrogen being used, with a maximal difference of ~25% between fermentations where no DAP was added versus addition at the start of the fermentation. The effect of the timing ofDAP addition on the expression of CARJ during fermentation was analyzed via northern transfer and the relative levels of CARl expression were determined. The trends in expression can be correlated to the nitrogen data and be used to partially explain differences in EC formation between the treatments. EC was quantified at the end of fermentation by GC/MS. In Montrachet yeast, a significant positive correlation was found between the timing of DAP addition, from early to late, and the final EC concentration m the wine (r = 0.9226). In one of the fermentations, EC levels of 30.5 ppb was foimd when DAP was added at the onset of fermentation. A twofold increase (69.5 ppb) was observed when DAP was added after 75% of the sugars were metabolized. When no DAP was added, the ethyl carbamate levels are comparable at a value of 38 ppb. In contrast, the timing of DAP additions do not affect the level EC produced by the yeast ECU 18 in this manner. The study of additional yeast strains shows that the effect of DAP addition to fermentations is strain dependent. Our results reveal the potential importance of the timing of DAP addition to grape must with respect to EC production, and the regulatory effect of DAP additions on the expression of genes in the pathway for arginine metabolism in certain wine yeast strains.
Resumo:
The adapted metabolic response of commercial wine yeast under prolonged exposure to concentrated solutes present in Icewine juice is not fully understood. Presently, there is no information regarding the transcriptomic changes in gene expression associated with the adaptive stress response ofwine yeast during Icewine fermentation compared to table wine fermentation. To understand how and why wine yeast respond differently at the genomic level and ultimately at the metabolic level during Icewine fermentation, the focus ofthis project was to identify and compare these differences in the wine yeast Saccharomyces cerevisiae KI-Vll16 using cDNA microarray technology during the first five days of fermentation. Significant differences in yeast gene expression patterns between fermentation conditions were correlated to differences in nutrient utilization and metabolite production. Sugar consumption, nitrogen usage and metabolite levels were measured using enzyme assays and HPLC. Also, a small subset of differentially expressed genes was verified using Northern analysis. The high osmotic stress experienced by wine yeast throughout Icewine fermentation elicited changes in cell growth and metabolism correlating to several fermentation difficulties, including reduced biomass accumulation and fermentation rate. Genes associated with carbohydrate and nitrogen transport and metabolism were expressed at lower levels in Icewine juice fermenting cells compared to dilute juice fermenting cells. Osmotic stress, not nutrient availability during Icewine fermentation appears to impede sugar and nitrogen utilization. Previous studies have established that glycerol and acetic acid production are increased in yeast during Icewine fermentation. A gene encoding for a glycerollW symporter (STL1) was found to be highly expressed up to 25-fold in the i Icewine juice condition using microarray and Northern analysis. Active glycerol transport by yeast under hyperosmotic conditions to increase cytosolic glycerol concentration may contribute to reduced cell growth observed in the Icewine juice condition. Additionally, genes encoding for two acetyl CoA synthetase isoforms (ACSl and ACS2) were found to be highly expressed, 19- and II-fold respectively, in dilute juice fermenting cells relative to the Icewine juice condition. Therefore, decreased conversion of acetate to acetyl-CoA may contribute to increased acetic acid production during Icewine fermentation. These results further help to explain the response of wine yeast as they adapt to Icewine juice fermentation. ii
Resumo:
In this study, methods of media literacy instruction including analytic activities, production activities, and a combination of analytic and production activities were compared to determine their influence on grade 8 students' knowledge, attitudes, and behaviours towards commercials. The findings showed that media literacy instruction does improve media literacy skills. Specifically, activities that included an analytic component or an analytic and production component were significantly better than activities that included a production component. Participants that completed analytic or analytic and production activities were able to discern media-related terms, target audience, selling techniques, social values, and stereotypes in commercials better than participants that completed only production activities. The research findings also showed obstacles when teaching media literacy. When engaged in analytic activities, the difficulties included locating suitable resources, addressing the competition from commercials, encouraging written reflection, recognizing social values, and discussing racial stereotypes. When engaged in production activities, the difficulties were positioning recording stations, managing group work, organizing ideas, filming the footage, computer issues, and scheduling time. Strategies to overcome these obstacles are described.
Resumo:
Icewine is an intensely s\veet dessert \vine fermented from the juice of naturally frozen grapes. Icewine fermentation poses many challenges such as failure to reach desired ethanol levels and production of high levels of volatile acidity in the fonn of acetic acid. This study investigated the impact of micronutrient addition (GO-FERM® and NATSTEP®) during the rehydration stage of the commercial \vine yeast Saccharomyces cerevisiae KI-VIII6 during Ice\vine fermentation. Sterile-filtered and unfiltered Riesling Ice\vine juice was inoculated \vith yeast rehydrated under four different conditions: in water only; with GO-FERM®; with NATSTEP®; or the combination of both micronutrient products in the rehydration water. Using sterile-filtered Icewine juice, yeast rehydration had a positive impact of reducing the rate of acetic acid produced as a function of sugar consumed, reducing the ratio of acetic acid/ethanol and reducing the ratio of acetic acid/glycerol. In the sterile-filtered fermentation, yeast rehydrated with micronutrients generated 9-times less acetic acid per gram of sugar in the first 48 hours compared to yeast rehydrated only \vith water and resulted in a 17% reduction in acetic acid in the final \vine \vhen normalized to sugar consumed. However, the sterile-filtered fermentations likely became stuck due to the overc1arification of the juice as evidenced from the low sugar consumption (117 gIL) that could not be completely overcome by the micronutrient treatments (144 gIL sugar consumed) to reach a target ethanol of IO%v/v. Contrary to \vhat \vas observed in the sterile-filtered treatements, using unfiltered Ice\vine juice, yeast micronutrient addition had no significant impact of reducing the rate of acetic acid produced as a function of sugar consumed, reducing the ratio of acetic acid/ethanol and reducing the ratio of acetic acid/glycerol. However, in the unfiltered fermentation, micronutrient addition during yeast rehydration caused a reduction in the acetic acid produced as a function of sugar consumed up to 150 giL sugar consumed.. In contrast to the sterile-filtered fermentations, the unfiltered fermentations did not become stuck as evidenced from the higher sugar consumption (l47-174g1L). The largest effects of micronutrient addition are evident in the first two days of both sterile and unfiltered fermentations.
Resumo:
The study examined coaches' usage of text-based computer-mediated communication (CMC) media (e.g., text-messaging, email) in the coach-player relationship. Data were collected by surveying Ontario-based male baseball coaches (n = 86) who coached players between 15 and 18 years old. Predictions were made regarding how demographic factors such as age and coaching experience affected coaches' CMC use and opinions. Results indicated that over 76% of respondents never used any CMC media other than email and team websites in their interactions with players. Results also revealed that coaches' usage rates contrasted with their opinion of the usefulness of the media, and their perception of players' use of the media. Coaches characterized most CMC media as limited, unnecessary, and sometimes inappropriate. Additional research should explore players' CMC usage rates and possible guidelines for use of the new media in authority relationships. Academia needs to keep pace with the developments in this area.
Resumo:
Icewine is an intensely sweet, unique dessert wine fennented from the juice of grapes that have frozen naturally on the vine. The juice pressed from the frozen grapes is highly concentrated, ranging from a minimum of 35° Brix to approximately 42° Brix. Often Icewine fennentations are sluggish, taking months to reach the desired ethanol level, and sometimes become stuck. In 6 addition, Icewines have high levels of volatile acidity. At present, there is no routine method of yeast inoculation for fennenting Icewine. This project investigated two yeast inoculum levels, 0.2 gIL and 0.5 gIL. The fennentation kinetics of inoculating these yeast levels directly into the sterile Icewine juice or conditioning the cells to the high sugar levels using a step wise acclimatization procedure were also compared. The effect of adding GO-FERM, a yeast nutrient, was also assessed. In the sterile fennentations, yeast inoculated at 0.2 gIL stopped fennenting before the required ethanol level was achieved, producing only 7.8% (v/v) and 8.1 % (v/v) ethanol for the direct and conditioned inoculations, respectively. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 12.2% (v/v) ethanol, whereas the direct inoculum produced 10.5% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the rate of biomass accumulation, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was no significant difference in acetic acid concentration in the final wines across all treatments. Fennentations using unfiltered Icewine juice at the 0.5 gIL inoculum level were also compared to see if the effects of yeast acclimatization and micronutrient addition had the same impact on fennentation kinetics and yeast metabolite production as observed in the sterile-filtered juice fennentations. In addition, a full descriptive analysis of the finished wines was carried out to further assess the impact of yeast inoculation method on Icewine sensory quality. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 11.5% (v/v) ethanol, whereas the direct inoculum produced 10.0% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the peak viable cell numbers, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was a significant difference 7 in acetic acid concentration in the final wines across all treatments and all treatments affected the sensory profiles of the final wines. Wines produced by direct inoculation were described by grape and raisin aromas and butter flavour. The addition of GO-FERM to the direct inoculation treatment shifted the aroma/flavour profiles to more orange flavour and aroma, and a sweet taste profile. StepWise acclimatizing the cells resulted in wines described more by peach and terpene aroma. The addition of GO-FERM shifted the profile to pineapple and alcohol aromas as well as alcohol flavour. Overall, these results indicate that the addition of GO-FERM and yeast acclimatization shortened the length of fermentation and impacted the sensory profiles of the resultant wines.
A biochemical predictor of performance during mesophilic anaerobic fermentation of starch wastewater
Resumo:
The aim of this study was to determine the potential of biochemical parameters, such as enzyme activity and adenosine triphosphate (ATP) levels, as monitors of process performance in the Upflow Anaerobic Sludge Blanket (UASB) reactor utilizing a starch wastewater. The acid and alkaline phosphatase activity and the ATP content of the UASB sludge were measured in response to changes in flow rate and nutrient loading. Conventional parameters of process performance, such as gas production, acetic acid production, COD, phosphorus, nitrogen and suspended solids loadings and % COD removal were also monitored. The response of both biochemical and conventional parameters to changing process conditions was then compared. Alkaline phosphatase activity exhibited the highest activity over the entire study perioda A high suspended solids loading was observed to upset the system in terms of gas production, acetic acid production and % COD removala The initial rate of increase in alkaline phosphatase activity following an increase in loading was four times as great during process upset than under conditions of good performance. The change in enzyme actiVity was also more sensitive to process upset than changes in acetic acid production. The change in ATP content of the sludge with time suggested that enzyme actiVity was changing independently of the actual viable biomass present. The bacterial composition of the anaerobic sludge granules was similar to that of other sludge bed systems, at the light and scanning electron microscope level. Isolated serum bottle cultures produced several acids involved in anaerobic carbohydrate metabolism. The overall performance of the UASB system indicated that higher loadings of soluble nutrients could have been tolerated by the system.
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This study examines issues of racism and sexism through the lens of Critical Race Theory and the interaction of personal and composite narratives. Specifically, the study explores how mainstream media’s hegemonic portrayal of South Asian culture and the 2007 socalled honour killing of Aqsa Parvez contribute to post-9/11 Islamophobia. The researcher presents a personal narrative that draws upon her experiences growing up in Dubai, U.A.E., and in Ontario, Canada and critically analyzes majoritarian stories related to Parvez as well as “counter-perspectives” that challenge such views. Study findings highlight the impact of 9/11 and Parvez’s murder on the researcher’s identity formation, and how media portray Muslim women as oppressed beings who live under the yoke of patriarchy. Results also indicate that although certain articles offer a counter-perspective that challenge dominant narratives, most recent media representations of the Parvez story equate Islam with honour killings and thus foster continued Islamophobia.
Resumo:
Please consult the paper edition of this thesis to read. It is available on the 5th Floor of the Library at Call Number: Z 9999.5 B63 P54 2007
Resumo:
This study sought to determine if and how the Ontario approach to integrating media education into the curriculum can be applied to Chinese education. The study used thematic analyses to identify the Ontario curriculum‘s attributes and approach to teaching media literacy, and to investigate relevant policies and national curriculum standards in Chinese compulsory education to reveal the status quo of Chinese media education. Finally, the study explored the feasibility of applying the Ontario media education model in China. Findings indicate that the Ontario model can be employed in the Chinese context, but only partly so, because current Chinese media education is limited by protectionism and restrictive policies corresponding to the use of media merely as research tools.
Resumo:
The past two centuries have witnessed the rise of nationalist movements and widespread nationalism. As these movements gained strength in Europe, sport played a role in their development. Media representations of sport recount events in a way that reinforces cultural values and this research investigates media representations of Croatian nationalism in the weeks surrounding the country’s third place victory in the 1998 FIFA World Cup. Sociological theories alongside more contemporary theories of sport and nation construction are considered. Croatian newspapers were analyzed for elements of national identity construction. The study concludes that the 1998 World Cup played an important role in Croatia’s on-going construction of nationhood and invention of nationalist traditions. This research further demonstrates sport’s ability to evoke strong emotions that are difficult to witness in other areas of social life and the direct role of sport in garnering nationalism.
Resumo:
The purpose of this research project was to use a qualitative approach to explore Critical Media Literacy (CML) with young girls by collaboratively analyzing Disney animated films. My goal was to provide a safe and encouraging space for children to share their perspectives and opinions of Disney animated female characters featured in The Little Mermaid (Ashman, Musker, & Clements, 1989), Cinderella (Disney, Geronimi, Jackson, & Luske, 1950), and The Princess and the Frog (Del Vecho, Clements, & Musker, 2009). I used CML as my theoretical framework as it provided an inquisitive approach to watching films, which, in turn, encouraged the participants to use critical thinking pertaining to the images of female characters in Disney. I also incorporated feminist theory as the majority of discussion revolved around the physical appearance of female characters as well as the participants’ understandings of femininity. I conducted two focus groups with 4 young girls, aged 7 to 11, to gain insight into their understanding of Disney female characters. An inquisitive and collaborative approach to watching films revealed three themes: (a) powerful women in Disney are mean and ugly; (b) heterosexual relationships are paramount; and (c) Disney Princesses are always pretty and nice. I concluded by recommending the importance of CML and collaborative film-watching with young children as the simplicity of asking questions encourages young people to become aware of, challenge, and think critically about the media they are consuming.
Resumo:
A media release from Inniskillin Wines announcing the launch of "Alliánce", a joint winemaking venture between Inniskillin and Jaffelin Wines of France.