scholarly journals Saccharomyces cerevisiae Fermentation of 28 Barley and 12 Oat Cultivars

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 59
Author(s):  
Timothy J. Tse ◽  
Daniel J. Wiens ◽  
Jianheng Shen ◽  
Aaron D. Beattie ◽  
Martin J. T. Reaney

As barley and oat production have recently increased in Canada, it has become prudent to investigate these cereal crops as potential feedstocks for alcoholic fermentation. Ethanol and other coproduct yields can vary substantially among fermented feedstocks, which currently consist primarily of wheat and corn. In this study, the liquified mash of milled grains from 28 barley (hulled and hull-less) and 12 oat cultivars were fermented with Saccharomyces cerevisiae to determine concentrations of fermentation products (ethanol, isopropanol, acetic acid, lactic acid, succinic acid, α-glycerylphosphorylcholine (α-GPC), and glycerol). On average, the fermentation of barley produced significantly higher amounts of ethanol, isopropanol, acetic acid, succinic acid, α-GPC, and glycerol than that of oats. The best performing barley cultivars were able to produce up to 78.48 g/L (CDC Clear) ethanol and 1.81 g/L α-GPC (CDC Cowboy). Furthermore, the presence of milled hulls did not impact ethanol yield amongst barley cultivars. Due to its superior ethanol yield compared to oats, barley is a suitable feedstock for ethanol production. In addition, the accumulation of α-GPC could add considerable value to the fermentation of these cereal crops.

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 894
Author(s):  
Johannes Pitsch ◽  
Georg Sandner ◽  
Jakob Huemer ◽  
Maximilian Huemer ◽  
Stefan Huemer ◽  
...  

Fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) are associated with digestive disorders and with diseases such as irritable bowel syndrome. In this study, we determined the FODMAP contents of bread, bakery products, and flour and assessed the effectiveness of sourdough fermentation for FODMAP reduction. The fermentation products were analyzed to determine the DP 2–7 and DP >7 fructooligosaccharide (FOS) content of rye and wheat sourdoughs. FOSs were reduced by Acetobacter cerevisiae, Acetobacter okinawensis, Fructilactobacillus sanfranciscensis, and Leuconostoc citreum to levels below those in rye (−81%; −97%) and wheat (−90%; −76%) flours. The fermentation temperature influenced the sourdough acetic acid to lactic acid ratios (4:1 at 4 °C; 1:1 at 10 °C). The rye sourdough contained high levels of beneficial arabinose (28.92 g/kg) and mannitol (20.82 g/kg). Our study contributes in-depth knowledge of low-temperature sourdough fermentation in terms of effective FODMAP reduction and concurrent production of desirable fermentation byproducts.


Fermentation ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 59 ◽  
Author(s):  
Tingting Liu ◽  
Shuangcheng Huang ◽  
Anli Geng

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.


2019 ◽  
Vol 20 (7) ◽  
pp. 1659
Author(s):  
Katarzyna Pielech-Przybylska ◽  
Maria Balcerek ◽  
Grzegorz Ciepielowski ◽  
Barbara Pacholczyk-Sienicka ◽  
Łukasz Albrecht ◽  
...  

The qualitative and quantitative composition of volatile compounds in fermented distillery mash determines the quality of the obtained distillate of agricultural origin (i.e., raw spirit) and the effectiveness of further purification steps. Propan-2-ol (syn. isopropyl alcohol), due to its low boiling point, is difficult to remove by rectification. Therefore, its synthesis needs to be limited during fermentation by Saccharomyces cerevisiae yeast, while at the same time controlling the levels of acetaldehyde and acetic acid, which are likewise known to determine the quality of raw spirit. Lactic acid bacteria (LAB) are a common but undesirable contaminant in distillery mashes. They are responsible for the production of undesirable compounds, which can affect synthesis of propan-2-ol. Some bacteria strains are able to synthesize isopropyl alcohol. This study therefore set out to investigate whether LAB with S. cerevisiae yeast are responsible for conversion of acetone to propan-2-ol, as well as the effects of the amount of LAB inoculum and fermentation parameters (pH and temperature) on the content of isopropyl alcohol, acetaldehyde, lactic acid and acetic acid in fermented mashes. The results of NMR and comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (GC × GC-TOF MS) analysis confirmed the ability of the yeast and LAB strains to metabolize acetone via its reduction to isopropyl alcohol. Efficient fermentation of distillery mashes was observed in all tested mashes with an initial LAB count of 3.34–6.34 log cfu/mL, which had no significant effect on the ethanol content. However, changes were observed in the contents of by-products. Lowering the initial pH of the mashes to 4.5, without and with LAB (3.34–4.34 log cfu/mL), resulted in a decrease in propan-2-ol and a concomitant increase in acetaldehyde content, while a higher pH (5.0 and 5.5) increased the content of propan-2-ol and decreased acetaldehyde content. Higher temperature (35 °C) promoted propan-2-ol synthesis and also resulted in increased acetic acid content in the fermented mashes compared to the controls. Moreover, the acetic acid content rose with increases in the initial pH and the initial LAB count.


2011 ◽  
Vol 77 (8) ◽  
pp. 2772-2784 ◽  
Author(s):  
Warren Albertin ◽  
Philippe Marullo ◽  
Michel Aigle ◽  
Christine Dillmann ◽  
Dominique de Vienne ◽  
...  

ABSTRACTAlcoholic fermentation (AF) conducted bySaccharomyces cerevisiaehas been exploited for millennia in three important human food processes: beer and wine production and bread leavening. Most of the efforts to understand and improve AF have been made separately for each process, with strains that are supposedly well adapted. In this work, we propose a first comparison of yeast AFs in three synthetic media mimicking the dough/wort/grape must found in baking, brewing, and wine making. The fermentative behaviors of nine food-processing strains were evaluated in these media, at the cellular, populational, and biotechnological levels. A large variation in the measured traits was observed, with medium effects usually being greater than the strain effects. The results suggest that human selection targeted the ability to complete fermentation for wine strains and trehalose content for beer strains. Apart from these features, the food origin of the strains did not significantly affect AF, suggesting that an improvement program for a specific food processing industry could exploit the variability of strains used in other industries. Glucose utilization was analyzed, revealing plastic but also genetic variation in fermentation products and indicating that artificial selection could be used to modify the production of glycerol, acetate, etc. The major result was that the overall maximum CO2production rate (Vmax) was not related to the maximum CO2production rate per cell. Instead, a highly significant correlation betweenVmaxand the maximum population size was observed in all three media, indicating that human selection targeted the efficiency of cellular reproduction rather than metabolic efficiency. This result opens the way to new strategies for yeast improvement.


2003 ◽  
Vol 376 (3) ◽  
pp. 781-787 ◽  
Author(s):  
Isabel SOARES-SILVA ◽  
Dorit SCHULLER ◽  
Raquel P. ANDRADE ◽  
Fátima BALTAZAR ◽  
Fernanda CÁSSIO ◽  
...  

In Saccharomyces cerevisiae the activity for the lactate–proton symporter is dependent on JEN1 gene expression. Pichia pastoris was transformed with an integrative plasmid containing the JEN1 gene. After 24 h of methanol induction, Northern and Western blotting analyses indicated the expression of JEN1 in the transformants. Lactate permease activity was obtained in P. pastoris cells with a Vmax of 2.1 nmol·s−1·mg of dry weight−1. Reconstitution of the lactate permease activity was achieved by fusing plasma membranes of P. pastoris methanol-induced cells with Escherichia coli liposomes containing cytochrome c oxidase, as proton-motive force. These assays in reconstituted heterologous P. pastoris membrane vesicles demonstrate that S. cerevisiae Jen1p is a functional lactate transporter. Moreover, a S. cerevisiae strain deleted in the JEN1 gene was transformed with a centromeric plasmid containing JEN1 under the control of the glyceraldehyde-3-phosphate dehydrogenase constitutive promotor. Constitutive JEN1 expression and lactic acid uptake were observed in cells grown on either glucose and/or acetic acid. The highest Vmax (0.84 nmol·s−1·mg of dry weight−1) was obtained in acetic acid-grown cells. Thus overexpression of the S. cerevisiae JEN1 gene in both S. cerevisiae and P. pastoris cells resulted in increased activity of lactate transport when compared with the data previously reported in lactic acid-grown cells of native S. cerevisiae strains. Jen1p is the only S. cerevisiae secondary porter characterized so far by heterologous expression in P. pastoris at both the cell and the membrane-vesicle levels.


1940 ◽  
Vol 11 (2) ◽  
pp. 136-144 ◽  
Author(s):  
C. C. Thiel

1. The influence of temperature, oxygen tension, yeast autolysate and chalk on the production of by-products and the ratios of by-products formed to sugar utilized and lactic acid produced in milk by the lactobacilli has been investigated.2. The total production of lactic acid is increased by the presence of chalk and “growth factors” but is not affected by temperature or oxygen tension. The ratio of lactic acid produced to sugar utilized is decreased at lower temperatures and increased by chalk but yeast autolysate and variation in oxygen tension give variable results.3. The total production of acetic acid is increased by the presence of chalk, and “growth factors” and by anaerobic conditions. The ratios of acetic acid produced to sugar utilized and lactic acid formed are decreased by chalk and anaerobic conditions and there is a tendency for the ratios to be decreased by the presence of yeast and increased at lower temperatures.4. The total production of alcohol is increased by anaerobiosis and also by the presence of chalk and yeast in the medium. The ratios of alcohol formed to sugar utilized and lactic acid produced is increased by anaerobic conditions, and chalk also tends to increase the relative amount of alcohol. Temperature and yeast autolysate have little effect.5. Chalk is effective in maintaining thepH at a higher level during growth, but the influence of chalk on the ratios of by-products formed to sugar utilized is probably not entirely a pS. effect since the addition of talc to the medium has an equally strong influence in altering the relative production of lactic acid and alcohol.6. It was previously shown for the heterofermentative streptococci that the Pasteur effect (suppression of alcoholic fermentation by respiration) is slight; similar results have been obtained with the heterofermentative lactobacilli.


2012 ◽  
Vol 57 (8) ◽  
pp. 2102-2108 ◽  
Author(s):  
Hee-Geun Nam ◽  
Geon-Woo Lim ◽  
Sungyong Mun

Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 67
Author(s):  
Fatma Bouaziz ◽  
Amal Ben Abdeddayem ◽  
Mohamed Koubaa ◽  
Francisco J. Barba ◽  
Khawla Ben Jeddou ◽  
...  

This study investigates the feasibility of producing ethanol from date palm seeds. The chemical compositions of three varieties of date seeds were first studied, showing mainly the presence of cellulose and hemicellulose. Ethanol was produced after a pre-treatment of date seeds using acid hydrolysis to extract the cellulosic fraction and to remove the lignin. Producing ethanol by fermentation was performed using the yeast Saccharomyces cerevisiae for 24 h, during which ethanol yield, biomass concentration, and total reducing sugars were recorded. The results obtained showed that the sugar content decreased over time, while ethanol production increased. Indeed, date seeds gave the highest ethanol concentration of 21.57 g/L after 6 h of alcoholic fermentation. These findings proved the feasibility of producing ethanol from date seeds.


2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Chae Eun Song ◽  
Han Hyo Shim ◽  
Palaniselvam Kuppusamy ◽  
Young-IL Jeong ◽  
Kyung Dong Lee

The objective of this study was to investigate alginate microencapsulated lactic acid bacteria (LAB) fermentation quality of radish kimchi sample and its potential survivability in different acidic and alkaline environments. Initially, we isolated 45 LAB strains. One of them showed fast growth pattern with potential probiotic and antifungal activities against Aspergillus flavus with a zone of inhibition calculated with 10, 8, 4mm for the 4th, 5th, and 6th day, respectively. Therefore, this strain (KCC-42) was chosen for microencapsulation with alginate biopolymer. It showed potential survivability in in-vitro simulated gastrointestinal fluid and radish kimchi fermentation medium. The survival rate of this free and encapsulated LAB KCC-42 was 6.85 × 105 and 7.48× 105 CFU/ml, respectively; the viability count was significantly higher than nonencapsulated LAB in simulated gastrointestinal juices (acid, bile, and pancreatin) and under radish kimchi fermentation environment. Kimchi sample added with this encapsulated LAB showed increased production of organic acids compared to nonencapsulated LAB sample. Also, the organic acids such as lactic acid, acetic acid, propionic acid, and succinic acid production in fermented kimchi were measured 59mM, 26mM, 14mM, and 0.6mM of g/DW, respectively. The production of metabolites such as lactic acid, acetic acid, and succinic acid and the bacteria population was high in microencapsulated LAB samples compared with free bacteria added kimchi sample. Results of this study indicate that microencapsulated LAB KCC-42 might be a useful strategy to develop products for food and healthcare industries.


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