Specific Ethanol Production Rate in Ethanologenic Escherichia coli Strain KO11 Is Limited by Pyruvate Decarboxylase

2008 ◽  
Vol 15 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Gerardo Huerta-Beristain ◽  
José Utrilla ◽  
Georgina Hernández-Chávez ◽  
Francisco Bolívar ◽  
Guillermo Gosset ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ethanol Production ◽  
Production Rate ◽  
Pyruvate Decarboxylase ◽  
Ethanol Production Rate

Research on Ethanol Production by Biological Fermentation of Potato Pulp

2013 ◽  
Vol 805-806 ◽  
pp. 281-285
Author(s):  
Zhong Xu
Keyword(s):  
Chemical Composition ◽  
Ethanol Production ◽  
Production Rate ◽  
Liquid Ratio ◽  
Fermentation Time ◽  
Potato Pulp ◽  
Fermentation Temperature ◽  
Ethanol Production Rate ◽  
Solid Liquid

Bioconversion of potato pulp to fuel ethanol, analysing the potato pulp chemical composition and determining the potato pulp in the role of microorganism produce ethanol under the best conditions is the major research. An analysis of the chemical composition of potato pulp showed that : the basic ingredients are Protein (9.72%), Starch (25.52%), Cellulose (17.90%). The effects of ethanol production rate of solid-liquid ratio, fermentation temperature, inoculumconcertration, fermentation time. The results showed that: the best conditions producting ethanol from potato pulp obtained by single factor experiments are: solid-liquid ratio: 1:15, fermentation temperature: 35°C, inoculumconcertration: 3mL, fermentation time: 20h. Under this occasion, the ethanol production rate was 0.183mL·g-1.

scholarly journals Tolerance of plum (Prunus domestica L.) fruits stored in low-oxygen atmosphere

2011 ◽  
Vol 31 (No. 1) ◽  
pp. 1-6
Author(s):  
J. Goliáš ◽  
A. Němcová ◽  
L. Šuderlová
Keyword(s):  
Ethanol Production ◽  
Production Rate ◽  
Storage Period ◽  
Final Concentration ◽  
Ambient Atmosphere ◽  
Prunus Domestica ◽  
Low Oxygen ◽  
Anaerobic Conditions ◽  
Storage Atmosphere ◽  
Ethanol Production Rate

Plum fruits of the cultivars Stanley and Valjevka picked at the beginning of climacteric were stored in different storage atmospheres for 31 days at 3&deg;C. The relations between the O<sub>2</sub> and CO<sub>2</sub> content during this period and after removal from the gas mixture to ethanol, acetaldehyde, non-volatile compounds and some textural values of fruits were investigated. Concentrations of ethanol in the flesh were related to levels of oxygen and CO<sub>2</sub> in ambient atmosphere. In anaerobic conditions (&lt; 0.2% O<sub>2</sub>) ethanol reached 1,109 mg/l for the cultivar Valjevka and 628 mg/l for Stanley. The results of single fruit analysis showed a steeply increasing concave curve of ethanol production in the period of anaerobic conditions, followed by the phase of a drop of the production rate in air stored fruit. The concentration of oxygen at a level of 0.9% (ultra low oxygen &ndash; ULO) does not physiologically harm the tissues of plums by producing mostly negligible content of ethanol and acetaldehyde, but an ethanol increase to half concentration after 31 days was observed to compare with anaerobic conditions in the cultivar Valjevka. From this aspect plums seem to be relatively sensitive to low oxygen. The post-storage period was extended up to 53 to 63 days, respectively. The senescence caused an increase in ethanol production rate that was exponentially increased after 20 days of cold storage atmosphere. The final concentration after 53 days was still higher for cv. Valjevka than for cv. Stanley at the respective content of 828 mg/land 498 mg/l. Skin firmness was differentiated for both cultivars, and softness was higher for the cultivar Valjevka. &nbsp;

Efficient photocatalytic conversion of CH4 into ethanol with O2 over nitrogen vacancy-rich carbon nitride at room temperature

2021 ◽  
Author(s):  
Zhongshan Yang ◽  
Qiqi Zhang ◽  
Liteng Ren ◽  
Xin Chen ◽  
Defa Wang ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Production Rate ◽  
Carbon Nitride ◽  
Room Temperature ◽  
Nitrogen Vacancy ◽  
Ethanol Production Rate

An ethanol production rate as high as 281.6 μmol g−1 h−1 was achieved during the photocatalytic conversion of CH4 in the presence of O2 at room temperature.

scholarly journals Flux through Citrate Synthase Limits the Growth of Ethanologenic Escherichia coli KO11 during Xylose Fermentation

2002 ◽  
Vol 68 (3) ◽  
pp. 1071-1081 ◽  
Author(s):  
S. A. Underwood ◽  
M. L. Buszko ◽  
K. T. Shanmugam ◽  
L. O. Ingram
Keyword(s):  
Escherichia Coli ◽  
Metabolic Engineering ◽  
Ethanol Production ◽  
Citrate Synthase ◽  
Corn Steep Liquor ◽  
Pyruvate Decarboxylase ◽  
Luria Broth ◽  
Mineral Salts ◽  
E Coli ◽  
Steep Liquor

ABSTRACT Previous studies have shown that high levels of complex nutrients (Luria broth or 5% corn steep liquor) were necessary for rapid ethanol production by the ethanologenic strain Escherichia coli KO11. Although this strain is prototrophic, cell density and ethanol production remained low in mineral salts media (10% xylose) unless complex nutrients were added. The basis for this nutrient requirement was identified as a regulatory problem created by metabolic engineering of an ethanol pathway. Cells must partition pyruvate between competing needs for biosynthesis and regeneration of NAD+. Expression of low-Km Zymomonas mobilis pdc (pyruvate decarboxylase) in KO11 reduced the flow of pyruvate carbon into native fermentation pathways as desired, but it also restricted the flow of carbon skeletons into the 2-ketoglutarate arm of the tricarboxylic acid pathway (biosynthesis). In mineral salts medium containing 1% corn steep liquor and 10% xylose, the detrimental effect of metabolic engineering was substantially reduced by addition of pyruvate. A similar benefit was also observed when acetaldehyde, 2-ketoglutarate, or glutamate was added. In E. coli, citrate synthase links the cellular abundance of NADH to the supply of 2-ketoglutarate for glutamate biosynthesis. This enzyme is allosterically regulated and inhibited by high NADH concentrations. In addition, citrate synthase catalyzes the first committed step in 2-ketoglutarate synthesis. Oxidation of NADH by added acetaldehyde (or pyruvate) would be expected to increase the activity of E. coli citrate synthase and direct more carbon into 2-ketoglutarate, and this may explain the stimulation of growth. This hypothesis was tested, in part, by cloning the Bacillus subtilis citZ gene encoding an NADH-insensitive citrate synthase. Expression of recombinant citZ in KO11 was accompanied by increases in cell growth and ethanol production, which substantially reduced the need for complex nutrients.

scholarly journals Simultaneous Biohydrogen and Bioethanol Production from Anaerobic Fermentation with Immobilized Sludge

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Wei Han ◽  
Zhanqing Wang ◽  
Hong Chen ◽  
Xin Yao ◽  
Yongfeng Li
Keyword(s):  
Acetic Acid ◽  
Ethanol Production ◽  
Production Rate ◽  
Anaerobic Fermentation ◽  
Hydrogen Yield ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Loading Rates ◽  
Ethanol Production Rate ◽  
Continuous Stirred Tank

The effects of organic loading rates (OLRs) on fermentative productions of hydrogen and ethanol were investigated in a continuous stirred tank reactor (CSTR) with attached sludge using molasses as substrate. The CSTR reactor with attached sludge was operated under different OLRs, ranging from 8 to 24 kg/m3·d. The H2and ethanol production rate essentially increased with increasing OLR. The highest H2production rate (10.74 mmol/hL) and ethanol production rate (11.72 mmol/hL) were obtained both operating at OLR = 24 kg/m3·d. Linear regression results show that ethanol production rate () and H2production rate () were proportionately correlated and can be expressed as (). The best energy generation rate was 19.08 kJ/hL, which occurred at OLR = 24 kg/m3·d. In addition, the hydrogen yield was affected by the presence of ethanol and acetic acid in the liquid phase, and the maximum hydrogen production rate occurred while the ratio of ethanol to acetic acid was close to 1.

scholarly journals Influence of autoinoculum on basic oenological parameters of wine

2020 ◽  
Vol 66 (4) ◽  
pp. 296-306
Author(s):  
Radim Holesinsky ◽  
Bozena Prusova ◽  
Mojmir Baron ◽  
Jaromir Fiala ◽  
Eliska Sembolova ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Production Rate ◽  
Sensory Evaluation ◽  
Sensory Analysis ◽  
Fermentation Process ◽  
Spontaneous Fermentation ◽  
Naturally Occurring ◽  
Natural Microflora ◽  
Ethanol Production Rate ◽  
Basic Parameters

In this paper we focus on possibilities of using natural microflora from vineyards to enhance spontaneous fermentation. Obtained yeast isolates, naturally occurring in vineyards, which were previously isolated in 2017 and 2018, were used for inoculation of Hibernal grape must. Spontaneously fermented musts and musts with the yeast isolates from 2017 and 2018 were compared. Basic parameters of the musts (sugar concentration, pH, concentration of titratable acids, concentration of assimilated nitrogen) were analysed studied, and a sensory analysis of the resultant wines was performed. The fermentation with the yeast isolates was quick and smooth. In the spontaneous fermentation lower ethanol production rate was observed at the end of the fermentation process. During the sensory evaluation, fruitiness of the spontaneously fermented batch was lower, but its vegetal characteristic was pronounced. The variant with the yeast isolates from 2017 was described as smooth, and the variant with yeast isolates from 2018 was evaluated as slightly vegetal.

Effects of potassium on the ethanol production rate of Saccharomyces cerevisiae carrying the plasmid pCYG4 related with ammonia assimilation

1992 ◽  
Vol 37 (1) ◽  
pp. 1-10 ◽  
Author(s):  
N. L. C. Licinio Da Silva ◽  
A. A. Salgueiro ◽  
W. M. Ledingham ◽  
E. H. M. Melo ◽  
J. L. Lima Filho
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Production Rate ◽  
Ammonia Assimilation ◽  
Ethanol Production Rate
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