Journal articles on the topic 'High sugar fermentation; Saccharomyces cerevisiae'
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1
Arrizon, Javier, and Anne Gschaedler. "Increasing fermentation efficiency at high sugar concentrations by supplementing an additional source of nitrogen during the exponential phase of the tequila fermentation process." Canadian Journal of Microbiology 48, no. 11 (November 1, 2002): 965–70. http://dx.doi.org/10.1139/w02-093.
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In the tequila industry, fermentation is traditionally achieved at sugar concentrations ranging from 50 to 100 g·L1. In this work, the behaviour of the Saccharomyces cerevisiae yeast (isolated from the juices of the Agave tequilana Weber blue variety) during the agave juice fermentation is compared at different sugar concentrations to determine if it is feasible for the industry to run fermentation at higher sugar concentrations. Fermentation efficiency is shown to be higher (above 90%) at a high concentration of initial sugar (170 g·L1) when an additional source of nitrogen (a mixture of amino acids and ammonium sulphate, different than a grape must nitrogen composition) is added during the exponential growth phase.Key words: Saccharomyces cerevisiae, fermentation efficiency, nitrogen source, tequila.
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Henderson, Clark M., Wade F. Zeno, Larry A. Lerno, Marjorie L. Longo, and David E. Block. "Fermentation Temperature Modulates Phosphatidylethanolamine and Phosphatidylinositol Levels in the Cell Membrane of Saccharomyces cerevisiae." Applied and Environmental Microbiology 79, no. 17 (June 28, 2013): 5345–56. http://dx.doi.org/10.1128/aem.01144-13.
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ABSTRACTDuring alcoholic fermentation,Saccharomyces cerevisiaeis exposed to a host of environmental and physiological stresses. Extremes of fermentation temperature have previously been demonstrated to induce fermentation arrest under growth conditions that would otherwise result in complete sugar utilization at “normal” temperatures and nutrient levels. Fermentations were carried out at 15°C, 25°C, and 35°C in a defined high-sugar medium using threeSaccharomyces cerevisiaestrains with diverse fermentation characteristics. The lipid composition of these strains was analyzed at two fermentation stages, when ethanol levels were low early in stationary phase and in late stationary phase at high ethanol concentrations. Several lipids exhibited dramatic differences in membrane concentration in a temperature-dependent manner. Principal component analysis (PCA) was used as a tool to elucidate correlations between specific lipid species and fermentation temperature for each yeast strain. Fermentations carried out at 35°C exhibited very high concentrations of several phosphatidylinositol species, whereas at 15°C these yeast strains exhibited higher levels of phosphatidylethanolamine and phosphatidylcholine species with medium-chain fatty acids. Furthermore, membrane concentrations of ergosterol were highest in the yeast strain that experienced stuck fermentations at all three temperatures. Fluorescence anisotropy measurements of yeast cell membrane fluidity during fermentation were carried out using the lipophilic fluorophore diphenylhexatriene. These measurements demonstrate that the changes in the lipid composition of these yeast strains across the range of fermentation temperatures used in this study did not significantly affect cell membrane fluidity. However, the results from this study indicate that fermentingS. cerevisiaemodulates its membrane lipid composition in a temperature-dependent manner.
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Bely, Marina, Isabelle Masneuf-Pomarède, and Denis Dubourdieu. "Influence of physiological state of inoculum on volatile acidity production by Saccharomyces cerevisiae during high sugar fermentation." OENO One 39, no. 4 (December 31, 2005): 191. http://dx.doi.org/10.20870/oeno-one.2005.39.4.886.
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<p style="text-align: justify;">An approach consisting of controlling yeast inoculum to minimize volatile acidity production by Saccharomyces cerevisiae during the alcoholic fermentation of botrytized must was investigated. Direct inoculation of rehydrated active dry yeasts produced the most volatile acidity, while a yeast preparation pre-cultured for 24 hours reduced the final production by up to 23 %. Using yeasts collected from a fermenting wine as a starter must also reduced volatile acidity production. The conditions for preparing the inoculum affected the fermentation capacity of the first generation yeasts: fermentation duration, sugar to ethanol ratio, and wine composition. A pre-culture medium with a low sugar concentration (< 220 g/L) is essential to limit volatile acidity production in high sugar fermentations.</p>
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Wang, Xuzeng, Zhaogai Wang, and Tao Feng. "Screening of Yeast in Various Vineyard Soil and Study on Its Flavor Compounds from Brewing Grape Wine." Molecules 27, no. 2 (January 14, 2022): 512. http://dx.doi.org/10.3390/molecules27020512.
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In order to screen out Saccharomyces cerevisiae suitable for table grape fermentation, and compare it with commercial Saccharomyces cerevisiae in terms of fermentation performance and aroma producing substances, differences of fermentation flavor caused by different strains were discussed. In this experiment, yeast was isolated and purified from vineyard soil, 26s rDNA identification and fermentation substrate tolerance analysis were carried out, and the causes of flavor differences of wine were analyzed from three aspects: GC-MS, PCA and sensory evaluation. The results showed that strain S1 had the highest floral aroma fraction, corresponding to its high production of ethyl octanoate and other substances, and it had the characteristics of high sugar tolerance. The fruit sensory score of S3 wine was the highest among the six wines. Through exploration and analysis, it was found that compared with commercial Saccharomyces cerevisiae, the screened strains had more advantages in fermenting table grapes. The flavor of each wine was directly related to the growth characteristics and tolerance of its strains.
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Le Thuong, Hoang Thi, Tran Thi Thuy, and Nguyen Quang Hao. "IMPROVEMENT OF THE ETHANOL PRODUCTION OF SACCHAROMYCES CEREVISIAE D8 BY THE RANDOM MUTAGENESIS." Vietnam Journal of Biotechnology 16, no. 2 (December 17, 2018): 337–44. http://dx.doi.org/10.15625/1811-4989/16/2/13446.
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Saccharomy cescerevisiae D8 isolated from Queen pineapple extract and selected for high ethanol fermentation activity (12.37% v/v ethanol concentration in fermentation media with a total sugar content of 200 g/L) has been reported previously (Hoang Thi Le Thuong et al., 2017). In this paper, the strain was subjected to random mutagenesis by N-methyl-N-nitro-N-nitrosoguanidine (NTG) and ultraviolet (UV) in order to enhance its ethanol fermentation. The results showed that 1% NTG was more lethal than UV (260 nm, 50 V) to S. cerevisiae D8 at the same time of treatment. The combination of NTG and UV was found to increase the mortality of S. cerevisiae D8. Surviving cells after treatment with NTG and UV combination were identified for ethanol fermentation. Thirteen clones were cabable of fermenting higher ethanol concentration than S. cerevisiae D8 was. Especially, mutant clone NU 120.4 was able to ferment glucose up to the highest ethanol concentration (22% higher than that of S. cerevisiae D8). This mutant clone also showed more tolerant to high ethanol and sugar concentrations in the fermentation medium than that of S. cerevisiae D8. The ethanol fermentation of this mutant was relatively stable in Queen pineapple extract (ethanol concentration of about 15.07 ± 0.12%) and the yield of ethanol fermentation was 92.62 ± 0.2%, while S. cerevisiae D8 gained maximum alcohol concentration of 12.37 ± 0.2%. In the context of the availability of pineapple used as primary source of food processing in Vietnam nowadays, these results showed a potential application of this mutant clone NU 120.4 in brandy production from pineapple extract.
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Vaquero, Cristian, Iris Loira, María Antonia Bañuelos, José María Heras, Rafael Cuerda, and Antonio Morata. "Industrial Performance of Several Lachancea thermotolerans Strains for pH Control in White Wines from Warm Areas." Microorganisms 8, no. 6 (June 1, 2020): 830. http://dx.doi.org/10.3390/microorganisms8060830.
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In the current scenario of climatic warming, the over-ripening of grapes increases the sugar content, producing flat and alcoholic wines with low acidity, high pH and low freshness. Additionally, a high pH makes wines more chemically and microbiologically unstable, requiring a higher sulphite content for preservation. Some strains of Lachancea thermotolerans can naturally lower the pH of wine by producing lactic acid from sugars; this pH reduction can reach 0.5 units. The industrial performance of four selected strains has been compared with that of two commercial strains and with that of Saccharomyces cerevisiae. The yeasts were assessed under variable oenological conditions, measuring lactic acid production and fermentative performance at two fermentation temperatures (17 and 27 °C), and in the presence or absence of sulphites (25 and 75 mg/L). Lactic acid production depends on yeast populations, with higher concentrations being reached when the microbial population is close to or above 7-log CFU/mL. A temperature effect on acidification can also be observed, being more intense at higher fermentation temperatures for most strains. Ethanol yield ranged from 7–11% vol., depending on the fermentation conditions (temperature and SO2) at day 12 of fermentation, compared with 12% for the S. cerevisiae control in micro-fermentations. The production of fermentative esters was higher at 27 °C compared with 17 °C, which favoured the production of higher alcohols. Volatile acidity was moderate under all fermentation conditions with values below 0.4 g/L.
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Carpena, Maria, Maria Fraga-Corral, Paz Otero, Raquel A. Nogueira, Paula Garcia-Oliveira, Miguel A. Prieto, and Jesus Simal-Gandara. "Secondary Aroma: Influence of Wine Microorganisms in Their Aroma Profile." Foods 10, no. 1 (December 27, 2020): 51. http://dx.doi.org/10.3390/foods10010051.
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Aroma profile is one of the main features for the acceptance of wine. Yeasts and bacteria are the responsible organisms to carry out both, alcoholic and malolactic fermentation. Alcoholic fermentation is in turn, responsible for transforming grape juice into wine and providing secondary aromas. Secondary aroma can be influenced by different factors; however, the influence of the microorganisms is one of the main agents affecting final wine aroma profile. Saccharomyces cerevisiae has historically been the most used yeast for winemaking process for its specific characteristics: high fermentative metabolism and kinetics, low acetic acid production, resistance to high levels of sugar, ethanol, sulfur dioxide and also, the production of pleasant aromatic compounds. Nevertheless, in the last years, the use of non-saccharomyces yeasts has been progressively growing according to their capacity to enhance aroma complexity and interact with S. cerevisiae, especially in mixed cultures. Hence, this review article is aimed at associating the main secondary aroma compounds present in wine with the microorganisms involved in the spontaneous and guided fermentations, as well as an approach to the strain variability of species, the genetic modifications that can occur and their relevance to wine aroma construction.
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Vucurovic, Vesna, and Radojka Razmovski. "Ethanol fermentation of molasses by Saccharomyces cerevisiae cells immobilized onto sugar beet pulp." Acta Periodica Technologica, no. 43 (2012): 325–33. http://dx.doi.org/10.2298/apt1243325v.
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Natural adhesion of Saccharomyces cerevisiae onto sugar beet pulp (SBP) is a very simple and cheap immobilization method for retaining high cells density in the ethanol fermentation system. In the present study, yeast cells were immobilized by adhesion onto SBP suspended in the synthetic culture media under different conditions such as: glucose concentration (100, 120 and 150 g/l), inoculum concentration (5, 10 and 15 g/l dry mass) and temperature (25, 30, 35 and 40?C). In order to estimate the optimal immobilization conditions the yeast cells retention (R), after each immobilization experiment was analyzed. The highest R value of 0.486 g dry mass yeast /g dry mass SBP was obtained at 30?C, glucose concentration of 150 g/l, and inoculum concentration of 15 g/l. The yeast immobilized under these conditions was used for ethanol fermentation of sugar beet molasses containing 150.2 g/l of reducing sugar. Efficient ethanol fermentation (ethanol concentration of 70.57 g/l, fermentation efficiency 93.98%) of sugar beet molasses was achieved using S. cerevisiae immobilized by natural adhesion on SBP.
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Oláhné Horváth, Borbála, Diána Nyitrainé Sárdy, Nikolett Kellner, and Ildikó Magyar. "Effects of the high sugar content on the fermentation dynamics and some metabolites of wine-related yeast species Saccharomyces cerevisiae, S. uvarum and Starmerella bacillaris." Food Technology and Biotechnology 58, no. 1 (April 22, 2020): 76–83. http://dx.doi.org/10.17113/ftb.58.01.20.6461.
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Starmerella bacillaris (synonym Candida zemplinina) is an important non-Saccharomyces yeast in winemaking with valuable oenological properties, accompanying Saccharomyces species in sweet wine fermentation, and has also been suggested for application as combined starter culture in dry or sweet wines. In this study, the major metabolites and nitrogen utilization of these yeasts are evaluated in the musts with high or extremely high sugar concentration. The change in the metabolic footprint of Saccharomyces cerevisiae, Saccharomyces uvarum and Starmerella bacillaris strains was compared when they were present as pure cultures in chemically defined grape juice medium with 220 and 320 g/L of sugar, to represent a fully matured and an overripe grape. Surprisingly, the extreme sugar concentration did not result in a considerable change in the rate of sugar consumption; only a shift of the sugar consumption curves could be noticed for all species, especially for Starmerella bacillaris. At the extreme sugar concentration, Starmerella bacillaris showed excellent glycerol production, moderate nitrogen demand together with a noticeable proline utilisation. The change in the overall metabolite pattern of Starmerella bacillaris allowed clear discrimination from the change of the Saccharomyces species. In this experiment, the adequacy of this non-Saccharomyces yeast for co-fermentation in juices with high sugar concentration is highlighted. Moreover, the results suggest that Starmerella bacillaris has a more active adaptation mechanism to extremely high sugar concentration.
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Rantsiou, Kalliopi, Paola Dolci, Simone Giacosa, Fabrizio Torchio, Rosanna Tofalo, Sandra Torriani, Giovanna Suzzi, Luca Rolle, and Luca Cocolin. "Candida zemplinina Can Reduce Acetic Acid Produced by Saccharomyces cerevisiae in Sweet Wine Fermentations." Applied and Environmental Microbiology 78, no. 6 (January 13, 2012): 1987–94. http://dx.doi.org/10.1128/aem.06768-11.
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ABSTRACTIn this study we investigated the possibility of usingCandida zemplinina, as a partner ofSaccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-fiveC. zemplininastrains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations withS. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels ofC. zemplininastarted to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pureS. cerevisiaefermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations ofS. cerevisiaeandC. zemplininaresulted in a decrease of ∼0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixedS. cerevisiaeandC. zemplininafermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to theS. cerevisiaeosmotic stress response.
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Mendes-Ferreira, A., M. del Olmo, J. García-Martínez, E. Jiménez-Martí, A. Mendes-Faia, J. E. Pérez-Ortín, and C. Leão. "Transcriptional Response of Saccharomyces cerevisiae to Different Nitrogen Concentrations during Alcoholic Fermentation." Applied and Environmental Microbiology 73, no. 9 (March 2, 2007): 3049–60. http://dx.doi.org/10.1128/aem.02754-06.
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ABSTRACT Gene expression profiles of a wine strain of Saccharomyces cerevisiae PYCC4072 were monitored during alcoholic fermentations with three different nitrogen supplies: (i) control fermentation (with enough nitrogen to complete sugar fermentation), (ii) nitrogen-limiting fermentation, and (iii) the addition of nitrogen to the nitrogen-limiting fermentation (refed fermentation). Approximately 70% of the yeast transcriptome was altered in at least one of the fermentation stages studied, revealing the continuous adjustment of yeast cells to stressful conditions. Nitrogen concentration had a decisive effect on gene expression during fermentation. The largest changes in transcription profiles were observed when the early time points of the N-limiting and control fermentations were compared. Despite the high levels of glucose present in the media, the early responses of yeast cells to low nitrogen were characterized by the induction of genes involved in oxidative glucose metabolism, including a significant number of mitochondrial associated genes resembling the yeast cell response to glucose starvation. As the N-limiting fermentation progressed, a general downregulation of genes associated with catabolism was observed. Surprisingly, genes encoding ribosomal proteins and involved in ribosome biogenesis showed a slight increase during N starvation; besides, genes that comprise the RiBi regulon behaved distinctively under the different experimental conditions. Here, for the first time, the global response of nitrogen-depleted cells to nitrogen addition under enological conditions is described. An important gene expression reprogramming occurred after nitrogen addition; this reprogramming affected genes involved in glycolysis, thiamine metabolism, and energy pathways, which enabled the yeast strain to overcome the previous nitrogen starvation stress and restart alcoholic fermentation.
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Панасюк, Александр, Alexander Panasyuk, Сергей Макаров, and Sergey Makarov. "Influence of different yeast races on quality parameters and antioxidant activity of wines produced from blackcurrant." Food Processing: Techniques and Technology 48, no. 1 (January 10, 2019): 66–73. http://dx.doi.org/10.21603/2074-9414-2018-1-66-73.
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Fermentation is the main technological stage of wine production. The objective of the article is to determine the dependence of qualitative parameters of wine material obtained from blackcurrant on the taken yeast race. The authors studied the influence of yeast on the blackcurrant mash fermentation dynamics, formation of secondary products, content of biologically active substances and antioxidant activity of the obtained wine material. The authors used Saccharomyces of two types: Saccharomyces vini – Chernosmorodinovaya 7, K-17, Moskva 30, Vishnevaya 33, K-72, and Saccharomyces cerevisiae – “Red Fruit”, WET 136, LW 317-29, UWY SP1. Mass fraction of total phenolic compounds content expressed in terms of gallic acid was determined applying spectrophotometric method using Folin-Chokalteuʼs reactant. Mass fraction of ascorbic acid was calculated using high-performance liquid chromatography. The authors measured antioxidant activity applying improved ABTS method on Shimadzu UV-1600 spectrophotometer (Japan). They found out that yeast races Saccharomyces cerevisiae had higher fermentation activity than Russian pure yeast races Saccharomyces vini. Saccharomyces cerevisiae surpassed Saccharomyces vini in sugar utilization and ethanol yield. The article reveals that fermentation with Saccharomyces cerevisiae having high fermentation capacity results in the increase of methanol content by 33–57% and decrease in ascorbic acid concentration by 69–83% compared to the wine base samples obtained using Saccharomyces vini. The authors established that phenolic compound concentration in the wine material depends on the period of contact with yeast and on the applied yeast race. They determined that antioxidant activity of the product mainly depends on ascorbic acid concentration and made a conclusion that yeast race determines product biological value and antioxidant activity substantially. The authors recommend to use Chernosmorodinovaya 7 in high quality blackcurrant wine production.
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Lin, Xueqing, Xiaohong Tang, Xiaomei Han, Xi He, Ning Han, Yan Ding, and Yuxia Sun. "Effect of Metschnikowia pulcherrima on Saccharomyces cerevisiae PDH By-Pass in MixedFermentation with Varied Sugar Concentrations of Synthetic Grape Juice and Inoculation Ratios." Fermentation 8, no. 10 (September 23, 2022): 480. http://dx.doi.org/10.3390/fermentation8100480.
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The effects of Metschnikowia pulcherrima and high glucose osmolality on S. cerevisiae pyruvate dehydrogenase pathway (PDH) by-pass were examined by varying the starting sugar concentration of synthetic grape juice and the inoculation ratio of S. cerevisiae to M. pulcherrima. The findings revealed that M. pulcherrima and osmolarity impacted S. cerevisiae’s PDH by-pass. The inoculation concentration of M. pulcherrima significantly affected pyruvate decarboxylase (PDC) activity and acs2 expression when the initial sugar concentration was 200 g L−1 and 290 g L−1. The osmolarity caused by the initial sugar (380 g L−1) significantly influenced the enzymatic activity of S. cerevisiae, which decreased PDC and acetaldehyde dehydrogenase (ALD) activities while increasing Acetyl-CoA synthetase (ACS) activity. The reduction in acetic acid in the wine was caused by M. pulcherrima altering the initial sugar concentration faced by S. cerevisiae, which in turn affected enzymatic activity. The alteration of enzyme activity and accumulation of primary metabolites revealed why mixed fermentation could reduce the acetic acid content in wine by altering the enzymatic activity and affecting the expression of several key genes. The M. pulcherrima inoculation levels had no significant effect on the acetic acid and glycerol concentration in the same fermentation medium.
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Wisselink, H. Wouter, Maurice J. Toirkens, M. del Rosario Franco Berriel, Aaron A. Winkler, Johannes P. van Dijken, Jack T. Pronk, and Antonius J. A. van Maris. "Engineering of Saccharomyces cerevisiae for Efficient Anaerobic Alcoholic Fermentation of l-Arabinose." Applied and Environmental Microbiology 73, no. 15 (June 1, 2007): 4881–91. http://dx.doi.org/10.1128/aem.00177-07.
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ABSTRACT For cost-effective and efficient ethanol production from lignocellulosic fractions of plant biomass, the conversion of not only major constituents, such as glucose and xylose, but also less predominant sugars, such as l-arabinose, is required. Wild-type strains of Saccharomyces cerevisiae, the organism used in industrial ethanol production, cannot ferment xylose and arabinose. Although metabolic and evolutionary engineering has enabled the efficient alcoholic fermentation of xylose under anaerobic conditions, the conversion of l-arabinose into ethanol by engineered S. cerevisiae strains has previously been demonstrated only under oxygen-limited conditions. This study reports the first case of fast and efficient anaerobic alcoholic fermentation of l-arabinose by an engineered S. cerevisiae strain. This fermentation was achieved by combining the expression of the structural genes for the l-arabinose utilization pathway of Lactobacillus plantarum, the overexpression of the S. cerevisiae genes encoding the enzymes of the nonoxidative pentose phosphate pathway, and extensive evolutionary engineering. The resulting S. cerevisiae strain exhibited high rates of arabinose consumption (0.70 g h−1 g [dry weight]−1) and ethanol production (0.29 g h−1 g [dry weight]−1) and a high ethanol yield (0.43 g g−1) during anaerobic growth on l-arabinose as the sole carbon source. In addition, efficient ethanol production from sugar mixtures containing glucose and arabinose, which is crucial for application in industrial ethanol production, was achieved.
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Bely, Marina, Philippe Stoeckle, Isabelle Masneuf-Pomarède, and Denis Dubourdieu. "Impact of mixed Torulaspora delbrueckii–Saccharomyces cerevisiae culture on high-sugar fermentation." International Journal of Food Microbiology 122, no. 3 (March 2008): 312–20. http://dx.doi.org/10.1016/j.ijfoodmicro.2007.12.023.
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Feghali, Nadine, Warren Albertin, Edouard Tabet, Ziad Rizk, Angela Bianco, Giacomo Zara, Isabelle Masneuf-Pomarede, and Marilena Budroni. "Genetic and Phenotypic Characterisation of a Saccharomyces cerevisiae Population of ‘Merwah’ White Wine." Microorganisms 7, no. 11 (October 26, 2019): 492. http://dx.doi.org/10.3390/microorganisms7110492.
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The study of yeast biodiversity represents an important step in the preservation of the local heritage, and this work in particular has an innovative character since no further studies have investigated ‘Merwah’, one of the main grape varieties used in winemaking in Lebanon. To gain deeper knowledge of the genetic diversity and population structure of native Saccharomyces cerevisiae wine strains, 202 isolates were collected during spontaneous alcoholic fermentation of eight must/wine samples of cultivar ‘Merwah’, over two consecutive years (2016, 2017) in a traditional winery in Mount Lebanon (1400 m a.s.l.). The isolates were identified as S. cerevisiae on the basis of their morphology and preliminary sequence analysis of their internal transcribed spacer (ITS) PCR. They were then characterised at the strain level by interdelta PCR and genotyped using multiplex PCR reactions of 12 microsatellite markers. High genetic diversity was observed for the studied population. To select potential yeast starter strains from this population, micro-fermentations were carried out for 22 S. cerevisiae strains that were selected as representative of the ‘Merwah’ wine yeast population in order to determine their technological and oenological properties. Three indigenous yeast strains might represent candidates for pilot-scale fermentation in the winery, based on relevant features such as high fermentation vigour, low production of volatile acidity and H2S and low residual sugar content at the end of alcoholic fermentation.
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Napitupulu, A. M. M., L. Suhendra, and I. B. W. Gunam. "Effect of Saccharomyces cerevisiae ATCC 9763 concentration and fermentation time on bioethanol content from corn stover crude cellulose substrate." IOP Conference Series: Earth and Environmental Science 913, no. 1 (November 1, 2021): 012026. http://dx.doi.org/10.1088/1755-1315/913/1/012026.
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Abstract Corn stover is a waste from the corn plant that dried in the fields after the corn cobs were harvested. From many corn wastes produced, there is very little utilization to corn stover. Delignified corn stover contains 65.46% cellulose, 14.58% hemicellulose, and 8.66% lignin. Lignocellulosic biomass is very difficult to biotransform, therefore it must be delignified to break the bonds between cellulose, hemicellulose, and lignin. Then the cellulose is converted into sugars by saccharification using crude cellulose enzymes so it can be converted into bioethanol through a fermentation process using simultaneous saccharification and fermentation (SSF) method. This study aims to determine the concentration of Saccharomyces cerevisiae ATCC 9763 and the optimum fermentation time in order to obtain high content of bioethanol from corn stover. Bioethanol production at different concentrations of S. cerevisiae and fermentation time uses a factorial randomized block design (RBD) consisting of two factors. The first factor was the concentration of S. cerevisiae which consisted of 3 levels, namely 3%, 5%, and 7% (v/v). The second factor was the fermentation time which consists of 4 levels, namely 24 hours, 48 hours, 72 hours, and 96 hours. Observed variables included pH value, total dissolved solids, reducing sugar content, and ethanol content. The data obtained were analyzed for its diversity using analysis of variants (ANOVA) and continued with the HSD Tukey. The results showed that the concentration of S. cerevisiae 7% (v/v) and a fermentation time of 96 hours was the best treatment to obtain a maximum ethanol content of 7.53 ± 0.330 g/L, with a final pH value of 4.25 ± 0.07, total dissolved solids 2.9 ± 0.14 °Bx and reducing sugar content of 0.334 ± 0.03 g/L. Increasing the concentration of S. cerevisiae and fermentation time can increase the ethanol content.
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An, Vo Ngoc, Van Thinh Pham, Vinh Long Do, Nguyen Quoc Duy, Thu Thuy Dang, and Tran Thien Hien. "The Influencing Factors on the Production of Alcoholic Drinking from Jackfruit (<i>Artocarpus heterophyllus</i> L.)." Materials Science Forum 1048 (January 4, 2022): 476–84. http://dx.doi.org/10.4028/www.scientific.net/msf.1048.476.
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The large amount of jackfruit (Artocarpus heterophyllus Lam) harvested and their short use time caused many difficulties for the farmers. Fortunately, the high sugar content in jackfruit meat is a hopeful substance for wine production. This study aimed to consider the effect of yeast strains and their concentration on fermented jackfruit solution. Jackfruit juice with 14 °Brix is fermented using 0.005 to 0.015% (w/v) Saccharomyces cerevisiae RV002, Mauri Instant Dry Yeast yeast under anaerobic conditions for 1 to 4 days at 30 °C. Survey samples were checked once a day to analyze the indicators. The functional report of the sugar in the fermentation time, shows that the higher incidence of yeast cultures and the initial sugar concentration inhibited yeast growth. The results showed that fermentation from jackfruit meat with 25 °Brix using Saccharomyces cerevisiae RV002 yeast with concentration of 0.01% for 3 days is the best to create a good quality with ethanol content 4,9% and characteristic aroma of jackfruit.
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Rahman, Shafkat Shamim, Md Mahboob Hossain, and Naiyyum Choudhury. "Effect of Various Parameters on the Growth and Ethanol Production by Yeasts Isolated from Natural Sources." Bangladesh Journal of Microbiology 30, no. 1-2 (June 25, 2016): 49–54. http://dx.doi.org/10.3329/bjm.v30i1-2.28453.
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Two ethanol fermenting Saccharomyces cerevisiae were isolated from date juice and grapes and grown in YEPD medium. They were characterized for alcoholic fermentation using sugarcane molasses and their growth conditions were optimized with respect to pH and sugar concentration. Results revealed a temperature of 30ºC, pH 6.0 and 6.5% sugar concentration as optimum for fermentation. Stress tolerance tests showed that date juice isolate was highly tolerant to temperature, pH and high ethanol concentration in the medium. Under optimized conditions, S. cerevisiae isolated from date-juice produced 7.75% of ethanol in molasses as estimated by Conway method.Bangladesh J Microbiol, Volume 30, Number 1-2,June-Dec 2013, pp 49-54
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Terpou, Antonia, Maria Dimopoulou, Aikaterini Belka, Stamatina Kallithraka, George-John E. Nychas, and Seraphim Papanikolaou. "Effect of Myclobutanil Pesticide on the Physiological Behavior of Two Newly Isolated Saccharomyces cerevisiae Strains during Very-High-Gravity Alcoholic Fermentation." Microorganisms 7, no. 12 (December 9, 2019): 666. http://dx.doi.org/10.3390/microorganisms7120666.
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Yeasts are able to act as biosorbents, as their cell wall includes several components capable of binding organic xenobiotic compounds that can potentially be removed during various fermentation processes. In the present investigation, two novel Saccharomyces cerevisiae strains (LMBF-Y 16 and LMBF-Y-18), previously isolated from grapes, were studied regarding their physiological behavior (dry cell weight—DCW production, substrate uptake, and ethanol and glycerol biosynthesis) during fermentations of grape must, in some cases enriched with commercial glucose and fructose (initial total sugar concentration approximately 150 and 250 g/L, respectively). Myclobutanil (a chiral triazole fungicide broadly used as a protective agent of vine) was also added to the culture media at various concentrations in order to assess the ability of the yeasts to simultaneously perform alcoholic fermentations and detoxify the medium (i.e., to remove the fungicide). In the first set of experiments and for both tested strains, trials were carried out in either 250 mL or 2.0 L agitated shake flasks in either synthetic glucose-based experiments or grape musts. Since the results obtained in the trials where the cultures were placed in 2.0 L flasks with grape musts as substrates were superior in terms of both DCW and ethanol production, these experimental conditions were selected for the subsequent studies. Both strains showed high fermentative efficiency, producing high amounts of DCW (9.5–10.5 g/L) in parallel with high ethanol production, which in some cases achieved values very close to the maximum theoretical ethanol production yield (≈0.49 g of ethanol per g of sugar). When using grape must with initial total sugars at approximately 250 g/L (very high gravity fermentation media, close to winemaking conditions), significantly high ethanol quantities (i.e., ranging between 105 and 123 g/L) were produced. Myclobutanil addition slightly negatively affected sugar conversion into ethanol; however, in all cases, ethanol production was very satisfactory. A non-negligible myclobutanil removal during fermentation, which ranged between 5%–27%, as a result of the adsorptive or degradative capacity of the yeast was also reported. The presence of myclobutanil had no effect on DCW production and resulted in no significant differences in the biosynthesis of glycerol. Therefore, these newly isolated yeast strains could be excellent candidates for simultaneous high ethanol production and parallel pesticide removal in a general biorefinery concept demonstrating many environmental benefits.
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Vucurovic, Vesna, Radojka Razmovski, Uros Miljic, and Vladimir Puskas. "Continuous ethanol production from sugar beet thick juice by Saccharomyces cerevisiae immobilized onto sugar beet pulp." Acta Periodica Technologica, no. 44 (2013): 313–21. http://dx.doi.org/10.2298/apt1344313v.
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The immobilization of Saccharomyces cerevisiae onto sugar beet pulp (SBP) by natural adhesion is an efficient and low-cost method for retaining high biocatalyst density in the ethanol fermentation system. In the present study, cells of S. cerevisiae 163, were immobilized by natural adhesion onto SBP. The retention of immobilized cells attained the level of about 1.7?1011 cells/gram of dry SBP. Continuous ethanol production from sugar beet thick juice (TJ) was performed in a cylinder glass bioreactor at a temperature of 30?C and pH 5 during a 27-day period. The stability of the fermentation process at dilution rate (D) of 0.025 h-1 and 0.05 h-1 was evaluated. The yeast-SBP system was shown to be stable for over a 15-day period at the dilution rate of 0.025 h-1, while the dilution rate of 0.05 h-1 was found to be unsuitable due to the intensive yeast leaching from the support. At D of 0.025 h-1 the maximum sugar utilization (Su), ethanol concentration (P), volumetric ethanol productivity (Qp), ethanol yield (Yp/s) and fermentation efficiency were 97.1%, 54.7 g/l, 2.3 g/lh, 0.498 g/g and 97.6%, respectively.
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., Wagiman, Makhmudun Ainuri, Rinda Gusvita, and Jumeri . "Design Process of Hydrolysis and Fermentation Bioethanol Production from Seaweed Eucheuma cottonii to Renewable Energy Sovereignity." KnE Life Sciences 3, no. 3 (January 1, 2016): 107. http://dx.doi.org/10.18502/kls.v3i3.390.
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<p>The aim of this research was study of E. cottonii to produce bioethanol fermentation substrate with a high reduction sugar content and low Hidroxymethilfurfural (HMF). Fermentation done by instant yeast and Saccharomyces cerevisiae culture of FNCC 3012.The best treatment was obtained in the combination of 2% of H2SO4 by time reaction of 120 minutes in 80°C produced 15.61 g/l reducing sugar and 5.03 g/l HMF. In fermented process, the hydrolysate with instant yeast starter delivered much more efficiency in 3.63 ml CO2 volume, 87.53% in fermentation efficiency, and 1.96 g/l reducing sugar on fifth day of fermentation. <br /><strong>Keywords</strong>: bioethanol, Eucheuma cottonii, fermentation, hydrolysis, process design</p>
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Elhussieny, Nadeem I., Marwah M. Bakri, Magdah Ganash, and Tarek M. Abdel Ghany. "Chemical mutagenesis of Saccharomyces cerevisiae for enhancing bioethanol production with fermentation at very high sugar concentration." BioResources 15, no. 1 (January 8, 2020): 1354–69. http://dx.doi.org/10.15376/biores.15.1.1354-1369.
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Saccharomyces cerevisiae is one of the most promising unicellular fungi on account of its vital applications in biotechnology as well as bioethanol production. Improvement of ethanol production via very high-gravity (VHG) fermentation (fermentation at high sugar levels) was successfully developed using the ethidium bromide (EtB) mutagenesis of S. cerevisiae. This study found two developed mutants of S. cerevisiae (EtB20a and EtB20b) with varied capacity for ethanol production using EtB, depending on random amplified polymorphic DNA analysis. Mutant EtB20b showed improved ethanol yield (19.5%) compared with the wild-type (18.0%), while the other mutant EtB20a exhibited retarded ethanol production (9.1%). Optimization of ethanol production by mutant EtB20b was performed under other conditions including temperature, pH, inoculum size, and incubation period. The highest production capacity of the yeasts was 20.8, 19.9, 19.5, and 19.5% at an optimum temperature of 30 °C, pH 6.0, incubation period of 72 h, and 1 mL of yeast suspension (optical density at 600 nm) with glucose utilization of 42.6, 40.7, 39.8, and 39.9%, respectively.
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Maftukhah, Siti, and Mutia Amyranti. "A Review Article : Ethanol Fermentation by Saccharomyces cerevisiae using Agricultural Waste." UNISTEK 7, no. 2 (August 25, 2020): 76–81. http://dx.doi.org/10.33592/unistek.v7i2.674.
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Bioethanol is one of the most promising and eco-friendly alternatives to fossil fuels, which is produced from renewable sources. Bioethanol can be produced from different kinds of raw materials. Conventional crops such as corn and sugarcane are unable to meet the global demand of bioethanol production due to their primary value of food and feed. Agricultural wastes are cost effective, renewable and abundant. To do this, very high gravity (VHG) fermentation which involves use of medium containing high sugar concentration(>250g/L) must be implemented to achieve high ethanol concentration. However, VHG fermentation leads to significant stress for Saccharomyces cerevisiae due to osmotic pressure at the beginning of the fermentation and high ethanol content at the end. At this review, rice straw is the most abundant waste compared to the other major wastes and potentially produce 205 billion liters bioethanol per year, which is the highest among these four mentioned agricultural wastes.
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Danmadami, Yabaya, Yahaya O, Abraham, Bobai M, and Orukotan A.A. "THE EFFICIENCY OF SACCAHROMYCES CEREVISIAE STRAIN ISOLATED FROM PALM WINE IN THE PRODUCTION OF BURUKUTU." International Journal of Research -GRANTHAALAYAH 5, no. 11 (November 30, 2017): 70–85. http://dx.doi.org/10.29121/granthaalayah.v5.i11.2017.2330.
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Non-availability and relatively high cost of obtaining the most effective commercially alcoholic fermentative Saccharomyces cereviciae strain is a major constrain in development and sustaining local industrial fermentation process. This study determined the alcoholic fermentative efficiency of Saccharomyces cereviciae strains isolated from palm wine in the production of burukutu. Palm wine was collected from Kachia, a sub-urban area of Kaduna, Kaduna State, Nigeria. Isolation was carried out using Sabouroud dextrose agar. Identification and characterization of Saccharomyces cereviciae from palm wine was carried out by microscopy and conventional biochemical methods and Analytical Profile Index. Alcoholic fermentative efficiency of the yeasts isolates was determined through fermentation of sorghum for the production of Burukutu. Ethanol tolerance and some physiological test were conducted. Cultural and morphological characteristics revealed smooth, creamy and white colonies on SDA, while cellular morphology was round and budded in arrangement. Biochemical identification and API showed isolate that was Glucose, Galactose, Raffinose, Acetyl D glucosamine positive and Glycerol, Inositol, Sorbitol, Arabinose, D –xylose, Adonitol Xylitol, Celiobiose, 2 – Ketoglutanal, Lactose, Maltose, Tretialose, Melezitose negative. HyphoePsedudohyphae and the control carbohydrate utilized were negative. The ethanol tolerance characteristics of the yeast revealed that the isolate had 8% ethanol tolerant. The pH of the Burukutu produced with Saccharomyces cerevisiae isolated from palm wine ranged from 3.8 – 6.2, in a manner showing pH decrease from 6.2 to 3.8 Within 24 hours’ fermentation period. Volatile acidity was also observed to have reduced during the study period. The total viable yeast also increased gradually, thus showing its ability to to metabolize sugar in sorghum to produce alcohol in burukutu.
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Trica, Bogdan, Oana Cristina Parvulescu, Tanase Dobre, Ali A. A. Al Janabi, Cristian Raducanu, and Claudia Patrichi. "Modelling of Ethanol Fermentation Coupled with Product Recovery by Pervaporation." Revista de Chimie 68, no. 11 (December 15, 2017): 2708–15. http://dx.doi.org/10.37358/rc.17.11.5960.
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Bioethanol is the most important biofuel produced by fermentation of sugars from various biomass types. The main disadvantages associated to this process consist in the negative effect of high ethanol concentration on the cell growth and in the separation cost of ethanol-water system resulted in the fermentation process. Sugar fermentation using Saccharomyces cerevisiae yeast coupled with bioethanol recovery by pervaporation has been modeled and simulated in this paper. In order to avoid the clogging of pervaporation membrane, the yeast cells were previously retained into an ultrafiltration unit. Three operating modes were analyzed and compared, i.e., classical batch fermentation (BF), batch fermentation coupled with external ultrafiltration and pervaporation (BFPV), and fed batch fermentation coupled with external ultrafiltration and pervaporation (FBFPV). Surface areas of ultrafiltration and pervaporation units were selected as process control variables.
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Nguyen, Trung D., Michelle E. Walker, Jennifer M. Gardner, and Vladimir Jiranek. "Appropriate vacuolar acidification in Saccharomyces cerevisiae is associated with efficient high sugar fermentation." Food Microbiology 70 (April 2018): 262–68. http://dx.doi.org/10.1016/j.fm.2017.09.021.
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Alves, Sergio L., Ricardo A. Herberts, Claudia Hollatz, Debora Trichez, Luiz C. Miletti, Pedro S. de Araujo, and Boris U. Stambuk. "Molecular Analysis of Maltotriose Active Transport and Fermentation by Saccharomyces cerevisiae Reveals a Determinant Role for the AGT1 Permease." Applied and Environmental Microbiology 74, no. 5 (January 18, 2008): 1494–501. http://dx.doi.org/10.1128/aem.02570-07.
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ABSTRACT Incomplete and/or sluggish maltotriose fermentation causes both quality and economic problems in the ale-brewing industry. Although it has been proposed previously that the sugar uptake must be responsible for these undesirable phenotypes, there have been conflicting reports on whether all the known α-glucoside transporters in Saccharomyces cerevisiae (MALx1, AGT1, and MPH2 and MPH3 transporters) allow efficient maltotriose utilization by yeast cells. We characterized the kinetics of yeast cell growth, sugar consumption, and ethanol production during maltose or maltotriose utilization by several S. cerevisiae yeast strains (both MAL constitutive and MAL inducible) and by their isogenic counterparts with specific deletions of the AGT1 gene. Our results clearly showed that yeast strains carrying functional permeases encoded by the MAL21, MAL31, and/or MAL41 gene in their plasma membranes were unable to utilize maltotriose. While both high- and low-affinity transport activities were responsible for maltose uptake from the medium, in the case of maltotriose, the only low-affinity (Km , 36 ± 2 mM) transport activity was mediated by the AGT1 permease. In conclusion, the AGT1 transporter is required for efficient maltotriose fermentation by S. cerevisiae yeasts, highlighting the importance of this permease for breeding and/or selection programs aimed at improving sluggish maltotriose fermentations.
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Hranilovic, Ana, Warren Albertin, Dimitra L. Capone, Adelaide Gallo, Paul R. Grbin, Lukas Danner, Susan E. P. Bastian, et al. "Impact of Lachancea thermotolerans on Chemical Composition and Sensory Profiles of Viognier Wines." Journal of Fungi 8, no. 5 (April 30, 2022): 474. http://dx.doi.org/10.3390/jof8050474.
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Viognier is a warm climate grape variety prone to loss of acidity and accumulation of excessive sugars. The yeast Lachancea thermotolerans can improve the stability and balance of such wines due to the partial conversion of sugars to lactic acid during alcoholic fermentation. This study compared the performance of five L. thermotolerans strains in co-inoculations and sequential inoculations with Saccharomyces cerevisiae in high sugar/pH Viognier fermentations. The results highlighted the dichotomy between the non-acidified and the bio-acidified L. thermotolerans treatments, with either comparable or up to 0.5 units lower pH relative to the S. cerevisiae control. Significant differences were detected in a range of flavour-active yeast volatile metabolites. The perceived acidity mirrored the modulations in wine pH/TA, as confirmed via “Rate-All-That-Apply” sensory analysis. Despite major variations in the volatile composition and acidity alike, the varietal aromatic expression (i.e., stone fruit aroma/flavour) remained conserved between the treatments.
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Vucurovic, Vesna, Radojka Razmovski, and Stevan Popov. "Ethanol production using Saccharomyces cerevisiae cells immobilised on corn stem ground tissue." Zbornik Matice srpske za prirodne nauke, no. 116 (2009): 315–22. http://dx.doi.org/10.2298/zmspn0916315v.
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Cell immobilisation in alcoholic fermentation has been extensively studied during the past few decades because of its technical and economical advantages over those of free cell systems. A biocatalyst was prepared by immobilising a commercial Saccharomyces cerevisiae strain (baker yeast) on corn stem ground tissue for use in alcoholic fermentation. For this purpose, the yeast cells were submitted to the batch tests 'in situ' adsorption onto pieces of the corn stem ground tissue. Cells immobilisation was analysed by optical microscopy. It was determined that the addition of the corn stem ground tissue led to an increase of the pH value, total dissolved salts content, and sugar content in fermentation medium. The addition of 5 and 10g of the corn stem ground tissue per liter of medium, increased ethanol yield, decreased amount of residual sugar and the cells immobilisation was effective. Corn stem is one of the abundant, available, inexpensive, stable, reusable, nontoxic celulosic biomaterial with high porosity, which facilitates the transmission of substrates and products between carrier and medium. The prepared immobilised biocatalyst showed higher fermentation activity than free cells. The results indicate that corn stem might be an interesting support for yeast cell immobilisation, and also a cheap alternative recourse of mineral components with possibility of application for improving ethanol productivities.
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Laopaiboon, Lakkana, Suntaree Suporn, Preekamol Klanrit, Niphaphat Phukoetphim, Chalida Daengbussadee, and Pattana Laopaiboon. "Novel Effective Yeast Strains and Their Performance in High Gravity and Very High Gravity Ethanol Fermentations from Sweet Sorghum Juice." Energies 14, no. 3 (January 22, 2021): 557. http://dx.doi.org/10.3390/en14030557.
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Yeasts were isolated from four potential sources, sweet sorghum juice, sugar cane juice, grapes and rambutan. The 27 yeast isolates were tested for their ethanol tolerance (15% v/v of ethanol) and ethanol fermentation performance in a synthetic ethanol production medium (200 g/L of total sugar). Only five isolates, SCJ04KKU, SCJ07KKU, SCJ09KKU, SCJ14KKU and SSJ01KKU could tolerate 15% ethanol and produce ethanol at levels higher than 55 g/L. The ethanol production efficiency from sweet sorghum juice under high gravity (HG, 200 and 240 g/L of total sugar) and very high gravity (VHG, 280 g/L of total sugar) conditions of the five isolates was tested. Saccharomyces cerevisiae NP01 and S. cerevisiae ATCC4132 were used as reference strains. The results showed that the SSJ01KKU isolate gave the highest ethanol production efficiency under all conditions. Ethanol concentration (PE), yield (YP/S) and productivity (QP) values were 98.89 g/L, 0.50 and 1.18 g/L·h, respectively, with sugar consumption (SC) of 98.96% under the HG condition at 200 g/L of total sugar. Under the HG condition at 240 g/L of total sugar, the PE, YP/S and QP values were 118.12 g/L, 0.51 and 1.41 g/L·h, respectively, with the SC of 95.79%. These values were 82.29 g/L, 0.34 and 0.98 g/L·h, respectively, with the SC of 85.59% under the VHG condition. Addition of urea into the sweet sorghum juice under all conditions significantly shortened the fermentation time, resulting in increased QP values. Based on molecular taxonomic analysis of the five isolates using sequence analysis of the D1/D2 domain and the ITS1 and ITS2 regions, SSJ01KKU is S. cerevisiae, whereas SCJ04KKU, SCJ07KKU, SCJ09KKU and SCJ14KKU are Pichia caribbica.
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Liu, Tingting, Shuangcheng Huang, and Anli Geng. "Recombinant Diploid Saccharomyces cerevisiae Strain Development for Rapid Glucose and Xylose Co-Fermentation." Fermentation 4, no. 3 (July 30, 2018): 59. http://dx.doi.org/10.3390/fermentation4030059.
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Cost-effective production of cellulosic ethanol requires robust microorganisms for rapid co-fermentation of glucose and xylose. This study aims to develop a recombinant diploid xylose-fermenting Saccharomyces cerevisiae strain for efficient conversion of lignocellulosic biomass sugars to ethanol. Episomal plasmids harboring codon-optimized Piromyces sp. E2 xylose isomerase (PirXylA) and Orpinomyces sp. ukk1 xylose (OrpXylA) genes were constructed and transformed into S. cerevisiae. The strain harboring plasmids with tandem PirXylA was favorable for xylose utilization when xylose was used as the sole carbon source, while the strain harboring plasmids with tandem OrpXylA was beneficial for glucose and xylose cofermentation. PirXylA and OrpXylA genes were also individually integrated into the genome of yeast strains in multiple copies. Such integration was beneficial for xylose alcoholic fermentation. The respiration-deficient strain carrying episomal or integrated OrpXylA genes exhibited the best performance for glucose and xylose co-fermentation. This was partly attributed to the high expression levels and activities of xylose isomerase. Mating a respiration-efficient strain carrying the integrated PirXylA gene with a respiration-deficient strain harboring integrated OrpXylA generated a diploid recombinant xylose-fermenting yeast strain STXQ with enhanced cell growth and xylose fermentation. Co-fermentation of 162 g L−1 glucose and 95 g L−1 xylose generated 120.6 g L−1 ethanol in 23 h, with sugar conversion higher than 99%, ethanol yield of 0.47 g g−1, and ethanol productivity of 5.26 g L−1·h−1.
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Ishmayana, Safri, Selvira Zenisya, Muhammad Fadhlillah, Agus Safari, and Ukun M. S. Soedjanaatmadja. "Optimization of Bioethanol Production from Molasses using Saccharomyces cerevisiae with Response Surface Method-Central Composite Design Approach." Research Journal of Chemistry and Environment 27, no. 1 (December 15, 2022): 86–93. http://dx.doi.org/10.25303/2701rjce86093.
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Bioethanol is one of alternative energy sources produced by fermenting carbohydrate rich materials with microorganism, especially the yeast Saccharomyces cerevisiae. It can be produced from feedstock with high carbohydrate content such as sugary, starchy and lignocellulosic materials. Molasses is a sugar production byproduct that has high glucose and other simple sugar content and therefore it is easy to ferment compared to starch or lignocellulosic materials that require pretreatment before fermentation. In the present study, we determine the optimum condition that can produce the highest ethanol using response surface method-central composite design (RSM-CCD) approach. Yeast strain used in the present study was Fali yeast, which is a commercially available industrial bioethanol strain. The concentration of molasses used in the present study was 40% (w/v) and factors optimized in the present study were pH, agitation rate and fermentation time. Twenty experiments were run based on the RSM-CCD using batch method. The results of the present study showed that the optimum condition was achieved when the pH, agitation rate and time of fermentation were 2, 368 rpm and 104 hours respectively. The concentration of ethanol reached 10.12% (w/v) at the optimum condition based on the model obtained. Validation of the model showed that 10.02% of ethanol can be achieved when the optimum condition was applied in laboratory experiment, indicating a good agreement between the mathematical model and experimental result.
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Gerőcs, Annamária, Tibor Nagy, Katalin Nemes-Barnás, János Májer, Barna Árpád Szőke, Róbert Kővágó, Frederico Magalhães, et al. "Characterization of Saccharomyces Strains Isolated from “Kéknyelű” Grape Must and Their Potential for Wine Production." Fermentation 8, no. 8 (August 22, 2022): 416. http://dx.doi.org/10.3390/fermentation8080416.
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Novel wine yeast strains have the potential to satisfy customer demand for new sensorial experiences and to ensure that wine producers have strains that can produce wine as efficiently as possible. In this respect, hybrid yeast strains have recently been the subject of intense research, as they are able to combine the favourable characteristics of both parental strains. In this study, two Saccharomyces “Kéknyelű” grape juice isolates were identified by species-specific PCR and PCR-RFLP methods and investigated with respect to their wine fermentation potential. Physiological characterization of the isolated strains was performed and included assessment of ethanol, sulphur dioxide, temperature and glucose (osmotic stress) tolerance, killer-toxin production, glucose fermentation ability at 16 °C and 24 °C, and laboratory-scale fermentation using sterile “Kéknyelű” must. Volatile components of the final product were studied by gas chromatography (GC) and mass spectrometry (MS). One isolate was identified as a S. cerevisiae × S. kudriavzevii hybrid and the other was S. cerevisiae. Both strains were characterized by high ethanol, sulphur dioxide and glucose tolerance, and the S. cerevisiae strain exhibited the killer phenotype. The hybrid isolate showed good glucose fermentation ability and achieved the lowest residual sugar content in wine. The ester production of the hybrid strain was high compared to the control S. cerevisiae starter strain, and this contributed to the fruity aroma of the wine. Both strains have good oenological characteristics, but only the hybrid yeast has the potential for use in wine fermentation.
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Aceituno, Felipe F., Marcelo Orellana, Jorge Torres, Sebastián Mendoza, Alex W. Slater, Francisco Melo, and Eduardo Agosin. "Oxygen Response of the Wine Yeast Saccharomyces cerevisiae EC1118 Grown under Carbon-Sufficient, Nitrogen-Limited Enological Conditions." Applied and Environmental Microbiology 78, no. 23 (September 21, 2012): 8340–52. http://dx.doi.org/10.1128/aem.02305-12.
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ABSTRACTDiscrete additions of oxygen play a critical role in alcoholic fermentation. However, few studies have quantitated the fate of dissolved oxygen and its impact on wine yeast cell physiology under enological conditions. We simulated the range of dissolved oxygen concentrations that occur after a pump-over during the winemaking process by sparging nitrogen-limited continuous cultures with oxygen-nitrogen gaseous mixtures. When the dissolved oxygen concentration increased from 1.2 to 2.7 μM, yeast cells changed from a fully fermentative to a mixed respirofermentative metabolism. This transition is characterized by a switch in the operation of the tricarboxylic acid cycle (TCA) and an activation of NADH shuttling from the cytosol to mitochondria. Nevertheless, fermentative ethanol production remained the major cytosolic NADH sink under all oxygen conditions, suggesting that the limitation of mitochondrial NADH reoxidation is the major cause of the Crabtree effect. This is reinforced by the induction of several key respiratory genes by oxygen, despite the high sugar concentration, indicating that oxygen overrides glucose repression. Genes associated with other processes, such as proline uptake, cell wall remodeling, and oxidative stress, were also significantly affected by oxygen. The results of this study indicate that respiration is responsible for a substantial part of the oxygen response in yeast cells during alcoholic fermentation. This information will facilitate the development of temporal oxygen addition strategies to optimize yeast performance in industrial fermentations.
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Sgouros, Georgios, Athanasios Mallouchos, Dimitra Dourou, Georgios Banilas, Ioanna Chalvantzi, Yiannis Kourkoutas, and Aspasia Nisiotou. "Torulaspora delbrueckii May Help Manage Total and Volatile Acidity of Santorini-Assyrtiko Wine in View of Global Warming." Foods 12, no. 1 (January 1, 2023): 191. http://dx.doi.org/10.3390/foods12010191.
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Non-Saccharomyces (NS) yeasts are gaining popularity in modern winemaking for improving wine quality. Climate change is one of the biggest challenges winegrowing now faces in warm regions. Here, Lachancea thermotolerans LtS1 and Torulaspora delbrueckii TdS6 combined with Saccharomyces cerevisiae ScS13 isolated from Assyrtiko grapes from Santorini island were evaluated in grape must fermentation with the aim to mitigate major consequences of temperature rise. Different inoculation protocols were evaluated, including simultaneous and sequential mixed-strain inoculations, displaying significant variation in the chemical and kinetic characteristics. Both LtS1 and TdS6 could raise the titratable acidity (TA). TdS6 also reduced the volatile acidity (VA) and was thus chosen for further evaluation in microvinifications and pilot-scale fermentations. Consistent with lab-scale trials, sequential inoculation exhibited the longest persistence of TdS6 resulting in minimum VA levels. Diethyl succinate, ethyl propanoate, and ethyl isobutyrate were significantly increased in sequential inoculations, although a decline in the net total ester content was observed. On the other hand, significantly higher levels of TA, succinic acid, and 2-methylpropanoic were associated with sequential inoculation. The overall performance of TdS6 coupled with a high compatibility with S. cerevisiae suggests its use in the fermentation of Santorini-Assyrtiko or other high sugar musts for the production of structured dry or sweet wines.
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Wisselink, H. Wouter, Maurice J. Toirkens, Qixiang Wu, Jack T. Pronk, and Antonius J. A. van Maris. "Novel Evolutionary Engineering Approach for Accelerated Utilization of Glucose, Xylose, and Arabinose Mixtures by Engineered Saccharomyces cerevisiae Strains." Applied and Environmental Microbiology 75, no. 4 (December 12, 2008): 907–14. http://dx.doi.org/10.1128/aem.02268-08.
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ABSTRACT Lignocellulosic feedstocks are thought to have great economic and environmental significance for future biotechnological production processes. For cost-effective and efficient industrial processes, complete and fast conversion of all sugars derived from these feedstocks is required. Hence, simultaneous or fast sequential fermentation of sugars would greatly contribute to the efficiency of production processes. One of the main challenges emerging from the use of lignocellulosics for the production of ethanol by the yeast Saccharomyces cerevisiae is efficient fermentation of d-xylose and l-arabinose, as these sugars cannot be used by natural S. cerevisiae strains. In this study, we describe the first engineered S. cerevisiae strain (strain IMS0003) capable of fermenting mixtures of glucose, xylose, and arabinose with a high ethanol yield (0.43 g g−1 of total sugar) without formation of the side products xylitol and arabinitol. The kinetics of anaerobic fermentation of glucose-xylose-arabinose mixtures were greatly improved by using a novel evolutionary engineering strategy. This strategy included a regimen consisting of repeated batch cultivation with repeated cycles of consecutive growth in three media with different compositions (glucose, xylose, and arabinose; xylose and arabinose; and only arabinose) and allowed rapid selection of an evolved strain (IMS0010) exhibiting improved specific rates of consumption of xylose and arabinose. This evolution strategy resulted in a 40% reduction in the time required to completely ferment a mixture containing 30 g liter−1 glucose, 15 g liter−1 xylose, and 15 g liter−1 arabinose.
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Galeote, Virginie, Maïté Novo, Madalena Salema-Oom, Christian Brion, Elisabete Valério, Paula Gonçalves, and Sylvie Dequin. "FSY1, a horizontally transferred gene in the Saccharomyces cerevisiae EC1118 wine yeast strain, encodes a high-affinity fructose/H+ symporter." Microbiology 156, no. 12 (December 1, 2010): 3754–61. http://dx.doi.org/10.1099/mic.0.041673-0.
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Transport of glucose and fructose in the yeast Saccharomyces cerevisiae plays a crucial role in controlling the rate of wine fermentation. In S. cerevisiae, hexoses are transported by facilitated diffusion via hexose carriers (Hxt), which prefer glucose to fructose. However, utilization of fructose by wine yeast is critically important at the end of fermentation. Here, we report the characterization of a fructose transporter recently identified by sequencing the genome of the commercial wine yeast strain EC1118 and found in many other wine yeasts. This transporter is designated Fsy1p because of its homology with the Saccharomyces pastorianus fructose/H+ symporter Fsy1p. A strain obtained by transformation of the V5 hxt1-7Δ mutant with FSY1 grew well on fructose, but to a much lesser extent on glucose as the sole carbon source. Sugar uptake and symport experiments showed that FSY1 encodes a proton-coupled symporter with high affinity for fructose (K m 0.24±0.04 mM). Using real-time RT-PCR, we also investigated the expression pattern of FSY1 in EC1118 growing on various carbon sources. FSY1 was repressed by high concentrations of glucose or fructose and was highly expressed on ethanol as the sole carbon source. The characteristics of this transporter indicate that its acquisition could confer a significant advantage to S. cerevisiae during the wine fermentation process. This transporter is a good example of acquisition of a new function in yeast by horizontal gene transfer.
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Pontes, Ana, Mathias Hutzler, Patrícia H. Brito, and José Paulo Sampaio. "Revisiting the Taxonomic Synonyms and Populations of Saccharomyces cerevisiae—Phylogeny, Phenotypes, Ecology and Domestication." Microorganisms 8, no. 6 (June 15, 2020): 903. http://dx.doi.org/10.3390/microorganisms8060903.
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Saccharomyces cerevisiae—the most emblematic and industrially relevant yeast—has a long list of taxonomical synonyms. Formerly considered as distinct species, some of the synonyms represent variants with important industrial implications, like Saccharomyces boulardii or Saccharomyces diastaticus, but with an unclear status, especially among the fermentation industry, the biotechnology community and biologists not informed on taxonomic matters. Here, we use genomics to investigate a group of 45 reference strains (type strains) of former Saccharomyces species that are currently regarded as conspecific with S. cerevisiae. We show that these variants are distributed across the phylogenetic spectrum of domesticated lineages of S. cerevisiae, with emphasis on the most relevant technological groups, but absent in wild lineages. We analyzed the phylogeny of a representative and well-balanced dataset of S. cerevisiae genomes that deepened our current ecological and biogeographic assessment of wild populations and allowed the distinction, among wild populations, of those associated with low- or high-sugar natural environments. Some wild lineages from China were merged with wild lineages from other regions in Asia and in the New World, thus giving more resolution to the current model of expansion from Asia to the rest of the world. We reassessed several key domestication markers among the different domesticated populations. In some cases, we could trace their origin to wild reservoirs, while in other cases gene inactivation associated with domestication was also found in wild populations, thus suggesting that natural adaptation to sugar-rich environments predated domestication.
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Varize, Camila S., Augusto Bücker, Lucas D. Lopes, Renata M. Christofoleti-Furlan, Mariane S. Raposo, Luiz C. Basso, and Boris U. Stambuk. "Increasing Ethanol Tolerance and Ethanol Production in an Industrial Fuel Ethanol Saccharomyces cerevisiae Strain." Fermentation 8, no. 10 (September 20, 2022): 470. http://dx.doi.org/10.3390/fermentation8100470.
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The stress imposed by ethanol to Saccharomyces cerevisiae cells are one of the most challenging limiting factors in industrial fuel ethanol production. Consequently, the toxicity and tolerance to high ethanol concentrations has been the subject of extensive research, allowing the identification of several genes important for increasing the tolerance to this stress factor. However, most studies were performed with well-characterized laboratory strains, and how the results obtained with these strains work in industrial strains remains unknown. In the present work, we have tested three different strategies known to increase ethanol tolerance by laboratory strains in an industrial fuel–ethanol producing strain: the overexpression of the TRP1 or MSN2 genes, or the overexpression of a truncated version of the MSN2 gene. Our results show that the industrial CAT-1 strain tolerates up to 14% ethanol, and indeed the three strategies increased its tolerance to ethanol. When these strains were subjected to fermentations with high sugar content and cell recycle, simulating the industrial conditions used in Brazilian distilleries, only the strain with overexpression of the truncated MSN2 gene showed improved fermentation performance, allowing the production of 16% ethanol from 33% of total reducing sugars present in sugarcane molasses. Our results highlight the importance of testing genetic modifications in industrial yeast strains under industrial conditions in order to improve the production of industrial fuel ethanol by S. cerevisiae.
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Hou, Lihua, Xiaohong Cao, and Chunling Wang. "A novel approach for the improvement of ethanol fermentation by Saccharomyces cerevisiae." Canadian Journal of Microbiology 56, no. 6 (June 2010): 495–500. http://dx.doi.org/10.1139/w10-032.
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Fermentation properties under the control of multiple genes are difficult to alter with traditional methods in Saccharomyces cerevisiae . Here, a novel genome engineering approach is developed to improve ethanol production in very high gravity fermentation with 300 g/L glucose as the carbon source. This strategy involved constructing aneuploid strains on the base of tetraploid cells. The tetraploid strain was constructed by using the plasmid YCplac33-GHK, which harbored the HO gene encoding the site-specific Ho endonucleases. The aneuploid strain, WT4-M, was selected and screened after the tetraploid cells were treated with methyl benzimidazole-2-yl-carbamate to induce loss of mitotic chromosomes. It was found that aneuploid strain WT4-M not only exhibited an increase in ethanol production and osmotic and thermal tolerance, but also an improvement in the sugar–ethanol conversion rate. Notably, WT4-M provided up to 9.8% improvement in ethanol production compared with the control strain. The results demonstrated that the strategy of aneuploidy was valuable for creating yeast strains with better fermentation characteristics.
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Bely, Marina, Alessandra Rinaldi, and Denis Dubourdieu. "Influence of assimilable nitrogen on volatile acidity production by Saccharomyces cerevisiae during high sugar fermentation." Journal of Bioscience and Bioengineering 96, no. 6 (January 2003): 507–12. http://dx.doi.org/10.1016/s1389-1723(04)70141-3.
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BELY, MARINA, ALESSANDRA RINALDI, and DENIS DUBOURDIEU. "Influence of Assimilable Nitrogen on Volatile Acidity Production by Saccharomyces cerevisiae during High Sugar Fermentation." Journal of Bioscience and Bioengineering 96, no. 6 (2004): 507–12. http://dx.doi.org/10.1263/jbb.96.507.
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Phiri, Archie, Daniel La Grange, and Kgabo Moganedi. "Microbial and Chemical Dynamics during Marula Wine Fermentation." Beverages 8, no. 3 (August 22, 2022): 50. http://dx.doi.org/10.3390/beverages8030050.
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Marula wine is traditionally produced through a spontaneous fermentation process and has a huge economic potential in Africa. The current study investigated the contributing microbiota and the metabolites produced during the wine fermentation process. Microbial communities were analyzed by selective cultivation and identified by biotyping and rDNA sequencing. Sugars and volatile compounds were determined with the high performance liquid chromatography and gas chromatography, respectively. Different Lactobacillus spp. were present throughout the fermentation process but dominated the earlier stages of fermentation, together with non-Saccharomyces yeasts, whereas Saccharomyces cerevisiae and acetic acid bacteria dominated the latter stages. Sucrose, glucose and fructose were detected during the early stages, while ethanol and butanol were present during the latter stages of fermentation. Interestingly, acetic acid and formic acid were detected in relatively high amounts at the latter stages of fermentation. Lactobacillus spp. and S. cerevisiae were identified as the primary contributing microbiota, and Acetobacter aceti and Acetobacter pasteuriannus were associated with the off taste and spoilage of the marula wine.
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Roncevic, Zorana, Bojana Bajic, Sinisa Dodic, Jovana Grahovac, Radmila Pajovic-Scepanovic, and Jelena Dodic. "Optimization of bioethanol production from soybean molasses using different strains of Saccharomyces cerevisiae." Chemical Industry 73, no. 1 (2019): 1–12. http://dx.doi.org/10.2298/hemind180713004r.
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Bioethanol technology represents an important scientific research area because of the high market value and wide availability of its primary and by-products. Worldwide interest in utilizing bioethanol as a renewable and sustainable energy source has significantly increased in the last few years due to limited reserves of fossil fuels and concerns about climate change. Therefore, improvement of the bioethanol production process is a priority research field at the international scale, due to both economic and environmental reasons. The aim of this study was to optimize production of bioethanol from soybean molasses based media using response surface methodology. Three different strains of the yeast Saccharomices cerevisiae, commercially available in dried form, were used as production microorganisms, and the best results were obtained by using dried baker?s yeast. The results of optimization of alcoholic fermentation using dried baker?s yeast indicate that the highest value of the overall desirability function (0.945) is obtained when the initial sugar content is 18.10 % (w/v) at the fermentation time of 48.00 h. At these conditions the model predicts that bioethanol concentration is 8.40 % (v/v), yeast cell number 2.21?108 cells/mL and the residual sugar content is 0.35 % (w/v).
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Kurniati, Yuni, Iis Elfy Khasanah, and Kurniawati Firdaus. "Kajian Pembuatan Bioetanol dari Limbah Kulit Nanas (Ananas comosus. L)." Jurnal Teknik Kimia USU 10, no. 2 (September 18, 2021): 95–101. http://dx.doi.org/10.32734/jtk.v10i2.6603.
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Ethanol is a fuel with a high octane number and is environmentally friendly. Bioethanol which can be made from biomass materials such as pineapple peel, is considered not to interfere with food security. With a fairly high carbohydrate and glucose content, pineapple can be converted into reducing sugars that can be fermented to produce ethanol. This study was conducted using the journal review method and aims to determine the mechanism, the variables that play the role, and the optimum conditions of fermentation in the manufacture of bioethanol from pineapple peel. The focus of the analysis was on hydrolysis, namely the type, concentration of the hydrolyzing agent, pH, temperature, and concentration of yeast in fermentation. The analysis from previous studies, the best hydrolysis was obtained by enzymatic hydrolysis using cellulase enzymes with a concentration of 1%-2%. The optimum pH of fermentation was found at pH 5 to pH 6, the fermentation temperature was 30 oC with a Saccharomyces cerevisiae concentration of 1.5% – 2%, and the optimum fermentation time occurred in the range of 48 to 96 hours. The high amount of reducing sugar produces a high amount of ethanol as well.
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Becker, Jessica, and Eckhard Boles. "A Modified Saccharomyces cerevisiae Strain That Consumes l-Arabinose and Produces Ethanol." Applied and Environmental Microbiology 69, no. 7 (July 2003): 4144–50. http://dx.doi.org/10.1128/aem.69.7.4144-4150.2003.
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ABSTRACT Metabolic engineering is a powerful method to improve, redirect, or generate new metabolic reactions or whole pathways in microorganisms. Here we describe the engineering of a Saccharomyces cerevisiae strain able to utilize the pentose sugar l-arabinose for growth and to ferment it to ethanol. Expanding the substrate fermentation range of S. cerevisiae to include pentoses is important for the utilization of this yeast in economically feasible biomass-to-ethanol fermentation processes. After overexpression of a bacterial l-arabinose utilization pathway consisting of Bacillus subtilis AraA and Escherichia coli AraB and AraD and simultaneous overexpression of the l-arabinose-transporting yeast galactose permease, we were able to select an l-arabinose-utilizing yeast strain by sequential transfer in l-arabinose media. Molecular analysis of this strain, including DNA microarrays, revealed that the crucial prerequisite for efficient utilization of l-arabinose is a lowered activity of l-ribulokinase. Moreover, high l-arabinose uptake rates and enhanced transaldolase activities favor utilization of l-arabinose. With a doubling time of about 7.9 h in a medium with l-arabinose as the sole carbon source, an ethanol production rate of 0.06 to 0.08 g of ethanol per g (dry weight) · h−1 under oxygen-limiting conditions, and high ethanol yields, this yeast strain should be useful for efficient fermentation of hexoses and pentoses in cellulosic biomass hydrolysates.
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Quyên, Nguyễn Văn, Nguyễn Quang Thảo, Nguyễn Thảo Anh, and Nguyễn Thành Đạt. "The influence of some factors on the reproduction and growth of Saccharomyces cerevisiae MS42." Vietnam Journal of Biotechnology 14, no. 3 (September 30, 2016): 523–32. http://dx.doi.org/10.15625/1811-4989/14/3/9869.
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Research on the growth of yeast is a critical requirement, occupying an important role in the technology of alcohol production. In reality, there are many factors affecting on the reproductive process and the growtht of yeast such as: temperature, pH, dissolved oxygen content, sugar content, nutrients, etc... The quantity and quality of yeast decide the quality on the wine products. When the amount of yeast is abundant, the fermentation speed is faster, which is an important factor in preventing infection from harmful microorganisms during fermentation. The study on influences affecting the growth of yeast is necessary to ensure the main aim of the propagation which is to create good quality breeding populations of yeast in a short time period. Furthermore, this has important implications for the fermentation process to create good products. Besides, increasing the speed and the number of yeast cells in practice, efficient, inexpensive materials used, as well as a common key element in the production process also bring high economic efficiency. In this study, basic factors affecting the growth of the species Saccharomyces cerevisiae MS42 we determined. Optimal conditions and compositions of the medium for breeding are shown in following: sugar content is 80 g/l: pH = 5.0; temperature from 28oC, the amount of dissolved oxygen from the initial is 7.0 mg/l, after 24 hours of incubation (since followed the same), the number of yeast cells has reached the maximum (219.5 ± 3.0 million cells/ml) and budding cell ratio (approximately 70 - 72%).
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Logotetis, Stilijanos, Panagiotis Tataridis, Anastasios Kanelis, and Elijas Nerancis. "The effect of preconditioning cells under osmotic stress on high alcohol production." Zbornik Matice srpske za prirodne nauke, no. 124 (2013): 405–14. http://dx.doi.org/10.2298/zmspn1324405l.
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This paper focuses on the research into the influence of salt on physiology of the yeast, Saccharomyces cerevisiae. Specifically, the work focused on how NaCl affected the growth, viability and fermentation performance of this yeast in laboratory-scale experiments. One of the main findings of the research presented involved the influ?ence of salt ?preconditioning? of yeasts which represents a method of pre-culturing of cells in the presence of salt in an attempt to improve subsequent fermentation performance. Such an approach resulted in preconditioned yeasts having an improved capability to ferment high-sugar containing media (up to 60% w/v of glucose) with increased cell viability and with increased levels of produced ethanol (higher than 20% in vol.). Salt-preconditioning was most likely influencing the stress-tolerance of yeasts by inducing the synthesis of key metabolites such as trehalose and glycerol which act to improve cells? ability to withstand osmostress and ethanol toxicity. The industrial-scale trials using salt-preconditioned yeasts verified the benefit of the physiological engineering approach to practical fermentations. Overall, this research has demonstrated that a relatively simple method designed to adapt yeast cells physiologically - by salt-preconditioning - can have distinct advantages for al?cohol fermentation processes.
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Muysson, Jared, Laurianne Miller, Robert Allie, and Debra L. Inglis. "The Use of CRISPR-Cas9 Genome Editing to Determine the Importance of Glycerol Uptake in Wine Yeast During Icewine Fermentation." Fermentation 5, no. 4 (October 30, 2019): 93. http://dx.doi.org/10.3390/fermentation5040093.
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The high concentration of sugars in Icewine juice causes formidable stress for the fermenting Saccharomyces cerevisiae, causing cells to lose water and shrink in size. Yeast can combat this stress by increasing the internal concentration of glycerol by activating the high osmolarity glycerol response to synthesize glycerol and by actively transporting glycerol into the cell from the environment. The H+/glycerol symporter, Stl1p, has been previously characterized as being glucose repressed and inactivated, despite osmotic stress induction. To further investigate the role of Stl1p in Icewine fermentations, we developed a rapid single plasmid CRISPR-Cas9-based genome editing method to construct a strain of the common Icewine yeast, S. cerevisiae K1-V1116, that lacks STL1. In an Icewine fermentation, the ∆STL1 strain had reduced fermentation performance, and elevated glycerol and acetic acid production compared to the parent. These results demonstrate that glycerol uptake by Stl1p has a significant role during osmotically challenging Icewine fermentations in K1-V1116 despite potential glucose downregulation.