Estimation of Ethanol Yield in Corn Mash Fermentations Using Mass of Ash as a Marker

2005 ◽  
Vol 111 (2) ◽  
pp. 137-143 ◽  
Author(s):  
R. Soto ◽  
I. Russell ◽  
N. Narendranath ◽  
R. Power ◽  
K. Dawson
Keyword(s):  
Ethanol Yield ◽  
Corn Mash

In Situ Corn Fiber Conversion for Ethanol Improvement by The Addition of Novel Lignocellulolytic Enzyme Cocktail

2020 ◽  
Author(s):  
Le Gao ◽  
Shulin Chen ◽  
Dongyuan Zhang
Keyword(s):  
Batch Fermentation ◽  
Ethanol Yield ◽  
Fermentation Broth ◽  
High Viscosity ◽  
Corn Fiber ◽  
Yeast Fermentation ◽  
Lignocellulolytic Enzymes ◽  
High Sugar ◽  
Corn Mash

Abstract Background: The technology of converting corn mashes to ethanol has been mature, but corn mashes has high-viscosity and high-sugar characteristics which hindered cellulose utilization and yeast-fermentation efficiency. The excessive viscosity of corn mash is caused by the presence of non-starch polysaccharides, such as cellulose in cereal grains. Corn kernel fiber (mostly cellulose) is typically unconverted in the process. Results: A novel lignocellulolytic enzymes cocktail with strong substrate specificity was prepared for high-viscosity, high-sugar corn mash. The in situ conversion of corn mashes with novel lignocellulolytic enzymes at the optimum cellulase dosage of 50 FPU/L resulted in 12.4%, 12.0%, 11.8%, and 12.9% increased ethanol concentration compared with the reference mash at 0.3, 1, 5, and 70 L batch-fermentation scales, respectively. The highest yield of ethanol from corn mash digested with the prepared novel lignocellulolytic enzyme reached 117.0 ± 0.1g/L at the 70 L batch fermentation, which was a 12.9% increase in ethanol yield. Adding the lignocellulolytic enzymes caused the greatest decrease in viscosity of corn mash by 40.9% compared with the reference mash (33.5 ± 1.5 Pa·s), whereas the residual sugars decreased by 56.3%. Simultaneously, the application of novel lignocellulolytic enzymes increased the value of dried distiller’s grain with solubles by increasing the protein content and decreasing the residual cellulose and starch content.Conclusion: The application of novel lignocellulolytic enzymes significantly improved the alcohol concentration, productivity, and yield. With the same amount of material, the application of the novel enzymes cocktail can enhance the ethanol yield by more than 10%. The in situ conversion of cellulose promoted the release of contents, including starch and protein, which can decrease the fermentation broth viscosity and improve the rheological property, thereby improving the ethanol yield. Thus, this technology can increase the net revenue of fuel-ethanol industrialization and promote the technological progress of renewable energy.

Bioethanol production from thermochemically pre-treated olive mill solid residues using the yeast Pachysolen tannophylus

2013 ◽  
Vol 14 (2) ◽  
pp. 118-124 ◽  
Keyword(s):  
Olive Oil ◽  
Ethanol Yield ◽  
Solid Residue ◽  
Residual Oil ◽  
Edible Fungi ◽  
Pachysolen Tannophilus ◽  
Three Phase ◽  
Different Types ◽  
Pre Treatment ◽  
Olive Mill

Olive oil mill solid residue (OMSR) is the solid waste generated during olive oil production process in three-phase olive mills. It consists of the remaining pulp of olive processing after the extraction of oil, as well as the cracked seeds of the olive fruits, containing thus mainly lignocellulose and residual oil. The commonly used practice for OMSR management is combustion, after having extracted the residual oil by secondary extraction using organic solvents. Other proposed ways of OMSR management are their exploitation as substrate for edible fungi production and compost, and as feedstock for biofuels generation such as methane and bioethanol. In the latter case, the complex carbohydrates (cellulose and hemicellulose) of the lignocellulose of OMSR have to be degraded towards their simple sugars and further fermented via microorganisms. The purpose of the present study was to investigate the effect of thermochemical pre-treatment of OMSR, on the final ethanol yield from the yeast Pachysolen tannophilus. Nine different types of OMSR-based substrates were tested i.e. raw OMSR, hydrolysates generated from pretreated OMSR with NaOH (0.5 %, 1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v), and pretreated OMSR with NaOH (0.5 %, 1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v) whole biomass. It was shown that in all cases pretreatment enhanced the consumption of carbohydrates as well as ethanol final yields.

scholarly journals Production of Methane, Hydrogen and Ethanol from Secale cereale L. Straw Pretreated with Sulfuric Acid

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 1013 ◽  
Author(s):  
Jarosław Domański ◽  
Olga Marchut-Mikołajczyk ◽  
Weronika Cieciura-Włoch ◽  
Piotr Patelski ◽  
Urszula Dziekońska-Kubczak ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Secale Cereale ◽  
Treatment Time ◽  
Ethanol Yield ◽  
Biofuel Production ◽  
Enzyme Treatment ◽  
Electricity Production ◽  
The European Union ◽  
Rye Straw ◽  
Secale Cereale L

The study describes sulfuric acid pretreatment of straw from Secale cereale L. (rye straw) to evaluate the effect of acid concentration and treatment time on the efficiency of biofuel production. The highest ethanol yield occurred after the enzyme treatment at a dose of 15 filter paper unit (FPU) per gram of rye straw (subjected to chemical hydrolysis with 2% sulfuric acid (SA) at 121 °C for 1 h) during 120 h. Anaerobic digestion of rye straw treated with 10% SA at 121 °C during 1 h allowed to obtain 347.42 L methane/kg volatile solids (VS). Most hydrogen was released during dark fermentation of rye straw after pretreatment of 2% SA, 121 °C, 1 h and 1% SA, 121 °C, 2 h—131.99 and 134.71 L hydrogen/kg VS, respectively. If the rye straw produced in the European Union were processed into methane, hydrogen, ethanol, the annual electricity production in 2018 could reach 9.87 TWh (terawatt-hours), 1.16 TWh, and 0.60 TWh, respectively.

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 Enzymatic Process for Cystoseira barbata Valorization: Ethanol Production and Additional By-Products

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 741
Author(s):  
Doinita-Roxana Cioroiu Tirpan ◽  
Ancaelena Eliza Sterpu ◽  
Claudia Irina Koncsag ◽  
Alina Georgiana Ciufu ◽  
Tănase Dobre
Keyword(s):  
Ethanol Production ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Product Yield ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Cystoseira Barbata ◽  
Main Factors ◽  
Process Factors

The aim of this study is to evaluate the potential of dried Cystoseira barbata alga for ethanol production through alcoholic fermentation. The influence of the main factors affecting the fermentation are studied in the frame of a 23 factorial experimental plan. The main factors influencing the process are the fermentation temperature (t from 25 °C to 35 °C), the solid to liquid ratio (S/L from 0.040 g/g to 0.080 g/g), and the cellulase ratio (R from 8 U/g d.m to 16 U/g d.m.). The maximum volatile compounds yield of 0.2808 g/g d.m and ethanol yield of 0.0158 g/g d.m were favored by the following experimental conditions: process temperature of 35 °C, solid to liquid ratio of 0.0415, and enzyme ratio of 16 U/g d.m. A statistical model was used to correlate the product yield with the process factors. Additionally, 19 interesting bioactive compounds were found in the enzymatic hydrolysis and alcoholic fermentation broths which seem likely to maintain natural defence mechanisms against diseases and physical disorders.

scholarly journals Hemicellulosic Bioethanol Production from Fast-Growing Paulownia Biomass

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 173
Author(s):  
Elena Domínguez ◽  
Pablo G. del Río ◽  
Aloia Romaní ◽  
Gil Garrote ◽  
Lucília Domingues
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Xylose Reductase ◽  
Energy Crop ◽  
Scheffersomyces Stipitis ◽  
Fractionation Process ◽  
Renewable Source ◽  
Fast Growing ◽  
Engineered Strain

In order to exploit a fast-growing Paulownia hardwood as an energy crop, a xylose-enriched hydrolysate was obtained in this work to increase the ethanol concentration using the hemicellulosic fraction, besides the already widely studied cellulosic fraction. For that, Paulownia elongata x fortunei was submitted to autohydrolysis treatment (210 °C or S0 of 4.08) for the xylan solubilization, mainly as xylooligosaccharides. Afterwards, sequential stages of acid hydrolysis, concentration, and detoxification were evaluated to obtain fermentable sugars. Thus, detoxified and non-detoxified hydrolysates (diluted or not) were fermented for ethanol production using a natural xylose-consuming yeast, Scheffersomyces stipitis CECT 1922, and an industrial Saccharomyces cerevisiae MEC1133 strain, metabolic engineered strain with the xylose reductase/xylitol dehydrogenase pathway. Results from fermentation assays showed that the engineered S. cerevisiae strain produced up to 14.2 g/L of ethanol (corresponding to 0.33 g/g of ethanol yield) using the non-detoxified hydrolysate. Nevertheless, the yeast S. stipitis reached similar values of ethanol, but only in the detoxified hydrolysate. Hence, the fermentation data prove the suitability and robustness of the engineered strain to ferment non-detoxified liquor, and the appropriateness of detoxification of liquor for the use of less robust yeast. In addition, the success of hemicellulose-to-ethanol production obtained in this work shows the Paulownia biomass as a suitable renewable source for ethanol production following a suitable fractionation process within a biorefinery approach.

scholarly journals Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song Wang ◽  
Ran Tian ◽  
Buwei Liu ◽  
Hongcai Wang ◽  
Jun Liu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
High Performance ◽  
Ethanol Yield ◽  
Starter Culture ◽  
Market Price ◽  
Sugarcane Molasses ◽  
Engineering Strain ◽  
Carbohydrate Utilization ◽  
Cane Molasses

AbstractSugarcane molasses are considered a potential source for bioethanol’s commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT–qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter’s pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.

scholarly journals High Potential of Pichia kluyveri and Other Pichia Species in Wine Technology

2021 ◽  
Vol 22 (3) ◽  
pp. 1196
Author(s):  
Javier Vicente ◽  
Fernando Calderón ◽  
Antonio Santos ◽  
Domingo Marquina ◽  
Santiago Benito
Keyword(s):  
Ethanol Yield ◽  
Color Stability ◽  
Quality Parameters ◽  
Wine Industry ◽  
Wine Aroma ◽  
Wine Quality ◽  
Promising Tool ◽  
Pichia Kluyveri ◽  
The Impact ◽  
Fermentative Yeast

The surfaces of grapes are covered by different yeast species that are important in the first stages of the fermentation process. In recent years, non-Saccharomyces yeasts such as Torulaspora delbrueckii, Lachancea thermotolerans, Metschnikowia pulcherrima, and Pichia kluyveri have become popular with regard to winemaking and improved wine quality. For that reason, several manufacturers started to offer commercially available strains of these non-Saccharomyces species. P. kluyveri stands out, mainly due to its contribution to wine aroma, glycerol, ethanol yield, and killer factor. The metabolism of the yeast allows it to increase volatile molecules such as esters and varietal thiols (aroma-active compounds), which increase the quality of specific varietal wines or neutral ones. It is considered a low- or non-fermentative yeast, so subsequent inoculation of a more fermentative yeast such as Saccharomyces cerevisiae is indispensable to achieve a proper fermented alcohol. The impact of P. kluyveri is not limited to the grape wine industry; it has also been successfully employed in beer, cider, durian, and tequila fermentation, among others, acting as a promising tool in those fermentation processes. Although no Pichia species other than P. kluyveri is available in the regular market, several recent scientific studies show interesting improvements in some wine quality parameters such as aroma, polysaccharides, acid management, and color stability. This could motivate yeast manufacturers to develop products based on those species in the near future.

scholarly journals Effects of Ultrasound on Fermentation of Glucose to Ethanol by Saccharomyces cerevisiae

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Luis Huezo ◽  
Ajay Shah ◽  
Frederick Michel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mass Transfer ◽  
Glucose Uptake ◽  
Ethanol Production ◽  
Ethanol Yield ◽  
Biofuel Production ◽  
Inhibitory Effects ◽  
Negative Effects ◽  
Intraparticle Mass Transfer ◽  
Improve Mass Transfer

Previous studies have shown that pretreatment of corn slurries using ultrasound improves starch release and ethanol yield during biofuel production. However, studies on its effects on the mass transfer of substrates and products during fermentation have shown that it can have both beneficial and inhibitory effects. In this study, the effects of ultrasound on mass transfer limitations during fermentation were examined. Calculation of the external and intraparticle observable moduli under a range of conditions indicate that no external or intraparticle mass transfer limitations should exist for the mass transfer of glucose, ethanol, or carbon dioxide. Fermentations of glucose to ethanol using Saccharomyces cerevisiae were conducted at different ultrasound intensities to examine its effects on glucose uptake, ethanol production, and yeast population and viability. Four treatments were compared: direct ultrasound at intensities of 23 and 32 W/L, indirect ultrasound (1.4 W/L), and no-ultrasound. Direct and indirect ultrasound had negative effects on yeast performance and viability, and reduced the rates of glucose uptake and ethanol production. These results indicate that ultrasound during fermentation, at the levels applied, is inhibitory and not expected to improve mass transfer limitations.

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