scholarly journals Bioethanol Production from Date Seed Cellulosic Fraction Using Saccharomyces cerevisiae

Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 67
Author(s):  
Fatma Bouaziz ◽  
Amal Ben Abdeddayem ◽  
Mohamed Koubaa ◽  
Francisco J. Barba ◽  
Khawla Ben Jeddou ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Date Palm ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Sugar Content ◽  
Biomass Concentration ◽  
Chemical Compositions ◽  
Yeast Saccharomyces Cerevisiae ◽  
Total Reducing Sugars ◽  
Pre Treatment

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.

Comparison of Bacterial and Yeast Ethanol Fermentation Yield from Rice Straw

2011 ◽  
Vol 347-353 ◽  
pp. 2541-2544
Author(s):  
Benjarat Laobussararak ◽  
Warawut Chulalaksananukul ◽  
Orathai Chavalparit
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Zymomonas Mobilis ◽  
Ethanol Yield ◽  
Sugar Content ◽  
Alkali Pretreatment ◽  
Yeast Saccharomyces Cerevisiae ◽  
Pretreatment Condition ◽  
Theoretical Yield

This study was to investigate the fermentation of rice straw using various microorganisms, i.e., the bacterium Zymomonas mobilis, a distillery yeast Saccharomyces cerevisiae and a co-culture of Zymomonas mobilis and Saccharomyces cerevisiae. Rice straw was pretreated with alkaline and followed by enzymatic hydrolysis using cellulase before fermentation by the bacterium and a distillery yeast. Results show that alkali pretreatment is appropriate for rice straw since this pretreatment condition can produce the maximum cellulose of 88.96% and reducing sugar content of 9.18 g/l. Furthermore, the ethanol yield after enzymatic hydrolysis (expressed as % theoretical yield) was 15.94-19.73% for the bacterium, 20.48-35.70% for yeast and 21.56-29.89% for co-culture. Therefore, the distillery yeast was a suitable microorganism for ethanol production from rice straw.

scholarly journals Ethanol production using Saccharomyces cerevisiae cells immobilised on corn stem ground tissue

2009 ◽  
pp. 315-322 ◽  
Author(s):  
Vesna Vucurovic ◽  
Radojka Razmovski ◽  
Stevan Popov
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcoholic Fermentation ◽  
Ph Value ◽  
Ethanol Yield ◽  
Sugar Content ◽  
Fermentation Medium ◽  
Yeast Cells ◽  
High Porosity ◽  
Ground Tissue ◽  
Cell Immobilisation

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.

scholarly journals Effect of various pretreatment methods on sugar and ethanol production from cellulosic water hyacinth

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 592-606
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ionic Liquid ◽  
Ethanol Production ◽  
Water Hyacinth ◽  
Reducing Sugars ◽  
Ethanol Yield ◽  
Sugar Content ◽  
The Other ◽  
Total Reducing Sugars ◽  
First Time

Effects of acid, alkali, ionic liquid (IL), and microwave-alkali pretreatments on cellulosic water hyacinth (WH) were investigated based on the total reducing sugars (TRS) and ethanol production. For the first time, IL pretreatment with (1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]) was used for WH, and the efficiency was compared with the other methods. Cellulase and Saccharomyces cerevisiae were fermented together for 72 h. Based on the results, all pretreatment methods effectively increased the sugar content as well as the ethanol yield. Untreated WH had 25 ± 1.5 mg/g of TRS, which was increased to 157 ± 8.2 mg/g, 95 ± 3.1 mg/g, 51 ± 4.2 mg/g, and 45 ± 2.6 mg/g via alkali, microwave-alkali, acid, and IL pretreatments, respectively. The highest TRS level of 402 mg/g was obtained in 24 h and 6.2 ± 0.4 g/L of ethanol in 48 h of fermentation with the alkali-treated WH. The ethanol production was followed by other treatment methods of WH in the order of microwave-alkali, acid, and IL. The results indicated that the ethanol production from WH was related to the type of pretreatment as well as the TRS production.

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
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Succinic Acid ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Cereal Crops ◽  
Fermentation Products ◽  
Barley Cultivars ◽  
Oat Cultivars

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.

scholarly journals Molecular Basis of Fructose Utilization by the Wine Yeast Saccharomyces cerevisiae: a Mutated HXT3 Allele Enhances Fructose Fermentation

2007 ◽  
Vol 73 (8) ◽  
pp. 2432-2439 ◽  
Author(s):  
Carole Guillaume ◽  
Pierre Delobel ◽  
Jean-Marie Sablayrolles ◽  
Bruno Blondin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Basis ◽  
Alcoholic Fermentation ◽  
Wine Yeast ◽  
Glycolytic Flux ◽  
Hexose Transporter ◽  
Wine Yeasts ◽  
Yeast Saccharomyces Cerevisiae ◽  
High Fructose ◽  
Fructose Fermentation

ABSTRACT Fructose utilization by wine yeasts is critically important for the maintenance of a high fermentation rate at the end of alcoholic fermentation. A Saccharomyces cerevisiae wine yeast able to ferment grape must sugars to dryness was found to have a high fructose utilization capacity. We investigated the molecular basis of this enhanced fructose utilization capacity by studying the properties of several hexose transporter (HXT) genes. We found that this wine yeast harbored a mutated HXT3 allele. A functional analysis of this mutated allele was performed by examining expression in an hxt1-7Δ strain. Expression of the mutated allele alone was found to be sufficient for producing an increase in fructose utilization during fermentation similar to that observed in the commercial wine yeast. This work provides the first demonstration that the pattern of fructose utilization during wine fermentation can be altered by expression of a mutated hexose transporter in a wine yeast. We also found that the glycolytic flux could be increased by overexpression of the mutant transporter gene, with no effect on fructose utilization. Our data demonstrate that the Hxt3 hexose transporter plays a key role in determining the glucose/fructose utilization ratio during fermentation.

scholarly journals Recombinant Diploid Saccharomyces cerevisiae Strain Development for Rapid Glucose and Xylose Co-Fermentation

Fermentation ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 59 ◽  
Author(s):  
Tingting Liu ◽  
Shuangcheng Huang ◽  
Anli Geng
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Xylose Isomerase ◽  
Cost Effective ◽  
Xylose Utilization ◽  
Yeast Strains ◽  
Multiple Copies ◽  
Biomass Sugars ◽  
Sugar Conversion

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.

scholarly journals Effect of some vitamins and micronutrient deficiencies on the production of higher alcohols by Saccharomyces cerevisiae

1993 ◽  
Vol 50 (3) ◽  
pp. 484-489 ◽  
Author(s):  
L.E. Gutierrez
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcoholic Fermentation ◽  
Isoamyl Alcohol ◽  
Higher Alcohols ◽  
Micronutrient Deficiencies ◽  
Isobutyl Alcohol ◽  
Yeast Saccharomyces Cerevisiae ◽  
Higher Alcohol ◽  
Alcohol Production ◽  
Acid Deficiency

A study was carried out in order to determine the effect of vitamins (biotin, thiamine, pantotheniic acid and pyridoxal) and micronutrient (zinc, boron, manganese and iron) deficiencies on higher alcohol production during alcoholic fermentation with the industrially used yeast Saccharomyces cerevisiae M-300-A. Zinc deficiency induced a reduction on the levels of isobutyl and isoamyl alcohols. An increase on isobutyl alcohol (fivefold) and a reduction of isoamyl alcohol (two fold) and n-propyl alcohol (three fold) contents resulted from pantotheiiic acid deficiency, whereas pyridoxal deficiency caused an increase on the levels of isobutyl and isoamyl alcohols. Biotin was not essential for the growth of this strain.

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