scholarly journals Production of Ethanol from Sugars and Lignocellulosic Biomass byThermoanaerobacterJ1 Isolated from a Hot Spring in Iceland

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jan Eric Jessen ◽  
Johann Orlygsson
Keyword(s):  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Hot Spring ◽  
Thermophilic Bacteria ◽  
Product Formation ◽  
Initial Glucose Concentration ◽  
Batch Cultures ◽  
Ethanol Yields ◽  
High Ethanol ◽  
Pretreated Biomass

Thermophilic bacteria have gained increased attention as candidates for bioethanol production from lignocellulosic biomass. This study investigated ethanol production byThermoanaerobacterstrain J1 from hydrolysates made from lignocellulosic biomass in batch cultures. The effect of increased initial glucose concentration and the partial pressure of hydrogen on end product formation were examined. The strain showed a broad substrate spectrum, and high ethanol yields were observed on glucose (1.70 mol/mol) and xylose (1.25 mol/mol). Ethanol yields were, however, dramatically lowered by adding thiosulfate or by cocultivating strain J1 with a hydrogenotrophic methanogen with acetate becoming the major end product. Ethanol production from 4.5 g/L of lignocellulosic biomass hydrolysates (grass, hemp stem, wheat straw, newspaper, and cellulose) pretreated with acid or alkali and the enzymes Celluclast and Novozymes 188 was investigated. The highest ethanol yields were obtained on cellulose (7.5 mM·g−1) but the lowest on straw (0.8 mM·g−1). Chemical pretreatment increased ethanol yields substantially from lignocellulosic biomass but not from cellulose. The largest increase was on straw hydrolysates where ethanol production increased from 0.8 mM·g−1to 3.3 mM·g−1using alkali-pretreated biomass. The highest ethanol yields on lignocellulosic hydrolysates were observed with hemp hydrolysates pretreated with acid, 4.2 mM·g−1.

Ethanol production by anaerobic thermophilic bacteria: Kinetics in fed-batch cultures ofClostridium thermohydrosulfuricum

1989 ◽  
Vol 11 (6) ◽  
pp. 443-448 ◽  
Author(s):  
Fatiou Toukourou ◽  
Luiz Donaduzzi ◽  
Andr� Miclo ◽  
Pierre Germain
Keyword(s):  
Ethanol Production ◽  
Thermophilic Bacteria ◽  
Fed Batch ◽  
Batch Cultures

scholarly journals Bioconversion process of source-separated organic waste for ethanol production

2021 ◽  
Author(s):  
Valeriy Bekmuradov
Keyword(s):  
Kinetic Model ◽  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Substrate Concentration ◽  
Ethanol Yield ◽  
Ethanol Conversion ◽  
Ethanol Yields ◽  
Environmental Goals ◽  
Ethanol Washing ◽  
Experimental Values

Production of biofuel such as ethanol from lignocellulosic biomass is a beneficial way to meet sustainability, energy security, and environmental goals. Lignocellulosic biomass such as source-separated organic (SSO) waste is particularly attractive since it is widely available, often at a negative cost, reduce the land depletion from using food-based biomass for ethanol production and reduce the amount of generated waste. Therefore, in order to meet the future fuel demands and cope with increasing volume of municipal waste this study was a first attempt to use SSO as a feedstock for ethanol production. The main objectives of the study were: a) to compare standard and modified celluloseorganic- solvent-based lignocellulosic fractionation (COSLIF) pretreatment of SSO waste for ethanol production in terms of enzyme savings, sugar formation and ethanol yields; b) to produce ethanol from SSO by using modified COSLIF pretreatment and fermentation with two different recombinant strains: Z. mobilis 8b and S. cerevisiae DA2416; and c) to develop experimental kinetic model capable of predicting behavior of batch SSCF on SSO waste with different SSO substrate concentrations using Berkeley Madonna program. Based on the obtained results, it was found that SSO is an excellent feedstock material for ethanol conversion. The efficiency of modified COSLIF pretreatment was improved by 20% compared to standard method using ethanol washing of pretreated SSO samples during the experimental procedures instead of acetone. On average, glucose yield from SSO samples pretreated by modified COSLIF was about 90% compared to 10% for untreated samples. S. cerevisiae DA2416 outperformed Z. mobilis 8b on ethanol yields during the fermentation process, with 0.50 g ethanol/g potential sugar fed on SSO in less than 5 days, with a 96% cellulose conversion, totalling in 150 g/L ethanol produced. A kinetic model with newly integrated values of experimentally defined SSO feedstock constants was proven to predict the ethanol yield accurately with substrate concentration ranges of 20 g/L - 50 g/L. Model prediction at higher substrate concentration (e.g. 100 g/L) deviated from the experimental values, suggesting that ethanol inhibition is a major factor in bioethanol conversion.

scholarly journals Bioconversion process of source-separated organic waste for ethanol production

2021 ◽  
Author(s):  
Valeriy Bekmuradov
Keyword(s):  
Kinetic Model ◽  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Substrate Concentration ◽  
Ethanol Yield ◽  
Ethanol Conversion ◽  
Ethanol Yields ◽  
Environmental Goals ◽  
Ethanol Washing ◽  
Experimental Values

Production of biofuel such as ethanol from lignocellulosic biomass is a beneficial way to meet sustainability, energy security, and environmental goals. Lignocellulosic biomass such as source-separated organic (SSO) waste is particularly attractive since it is widely available, often at a negative cost, reduce the land depletion from using food-based biomass for ethanol production and reduce the amount of generated waste. Therefore, in order to meet the future fuel demands and cope with increasing volume of municipal waste this study was a first attempt to use SSO as a feedstock for ethanol production. The main objectives of the study were: a) to compare standard and modified celluloseorganic- solvent-based lignocellulosic fractionation (COSLIF) pretreatment of SSO waste for ethanol production in terms of enzyme savings, sugar formation and ethanol yields; b) to produce ethanol from SSO by using modified COSLIF pretreatment and fermentation with two different recombinant strains: Z. mobilis 8b and S. cerevisiae DA2416; and c) to develop experimental kinetic model capable of predicting behavior of batch SSCF on SSO waste with different SSO substrate concentrations using Berkeley Madonna program. Based on the obtained results, it was found that SSO is an excellent feedstock material for ethanol conversion. The efficiency of modified COSLIF pretreatment was improved by 20% compared to standard method using ethanol washing of pretreated SSO samples during the experimental procedures instead of acetone. On average, glucose yield from SSO samples pretreated by modified COSLIF was about 90% compared to 10% for untreated samples. S. cerevisiae DA2416 outperformed Z. mobilis 8b on ethanol yields during the fermentation process, with 0.50 g ethanol/g potential sugar fed on SSO in less than 5 days, with a 96% cellulose conversion, totalling in 150 g/L ethanol produced. A kinetic model with newly integrated values of experimentally defined SSO feedstock constants was proven to predict the ethanol yield accurately with substrate concentration ranges of 20 g/L - 50 g/L. Model prediction at higher substrate concentration (e.g. 100 g/L) deviated from the experimental values, suggesting that ethanol inhibition is a major factor in bioethanol conversion.

The ingfluence of temperature, pH and aeration on the ethanolic fermentation of glucose by Pachysolen tannophilus

1989 ◽  
Vol 54 (5) ◽  
pp. 1244-1256 ◽  
Author(s):  
F. Camacho Rubio ◽  
V. Bravo Rodríguez ◽  
S. Sánchez Villasclaras ◽  
M. Castro Vico
Keyword(s):  
Ethanol Production ◽  
Ethanol Yield ◽  
Glucose Consumption ◽  
Ethanolic Fermentation ◽  
Pachysolen Tannophilus ◽  
Batch Cultures ◽  
Initial Ph ◽  
Ethanol Yields ◽  
C 30 ◽  
Rates Of Growth

The ethanolic fermentation of 25 g l-1 solutions of glucose in batch cultures of Pachysolen tannophilus has been studied experimentally in terms of three environmental variables: initial pH from 1.5 to 6.5, temperatures of 25 °C, 30 °C and 35 °C and aeration values of Q = 0.150 v/v/min, Q = 0.075 v/v/min and Q = 0 v/v/min (i.e. with air entering through the stirring vortex alone). Using the values for the concentrations of biomass, residual glucose and ethanol produced at intervals throughout the experiments, the maximum specific rates of growth, glucose consumption and ethanol production, together with the biomass and ethanol yields, have been calculated. The most favourable conditions for ethanol production are an initial pH of about 3, temperature of 30 °C and Q = 0 v/v/min. Under these conditions the ethanol yield is approximately 0.36 (g ethanol) (g glucose)-1 and the maximum specific production rate is 1.2 (g ethanol) (g biomass)-1 h-1.

The influence of the initial concentrations of glucose and yeast extract on the ethanolic fermentation by Pachysolen tannophilus

1990 ◽  
Vol 55 (3) ◽  
pp. 854-866 ◽  
Author(s):  
Rodríguez V. Bravo ◽  
Rubio F. Camacho ◽  
Villasclaras S. Sánchez ◽  
Vico M. Castro
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Culture Medium ◽  
Ethanolic Fermentation ◽  
Pachysolen Tannophilus ◽  
Significant Component ◽  
Batch Cultures

The ethanolic fermentation in batch cultures of Pachysolen tannophilus was studied experimentally varying the initial concentrations of two of the components in the culture medium: glucose between 0 and 200 g l-1 and yeast extract between 0 and 8 g l-1. The yeast extract appears to be a significant component both in cell growth and for ethanol production.

scholarly journals Kinetics and Metabolism of Bifidobacterium adolescentis MB 239 Growing on Glucose, Galactose, Lactose, and Galactooligosaccharides

2007 ◽  
Vol 73 (11) ◽  
pp. 3637-3644 ◽  
Author(s):  
Alberto Amaretti ◽  
Tatiana Bernardi ◽  
Elena Tamburini ◽  
Simona Zanoni ◽  
Mariella Lomma ◽  
...  
Keyword(s):  
Growth Rate ◽  
Recursive Algorithm ◽  
Carbon Fluxes ◽  
Degree Of Polymerization ◽  
Substrate Selectivity ◽  
Carbon Distribution ◽  
Bifidobacterium Adolescentis ◽  
Fermentation Products ◽  
Batch Cultures ◽  
Ethanol Yields

ABSTRACT The kinetics and the metabolism of Bifidobacterium adolescentis MB 239 growing on galactooligosaccharides (GOS), lactose, galactose, and glucose were investigated. An unstructured unsegregated model for growth in batch cultures was developed, and kinetic parameters were calculated with a recursive algorithm. The growth rate and cellular yield were highest on galactose, followed by lactose and GOS, and were lowest on glucose. Lactate, acetate, and ethanol yields allowed the calculation of carbon fluxes toward fermentation products. Distributions between two- and three-carbon products were similar on all the carbohydrates (55 and 45%, respectively), but ethanol yields were different on glucose, GOS, lactose, and galactose, in decreasing order of production. Based on the stoichiometry of the fructose-6-phosphate shunt and on the carbon distribution among the products, the ATP yield was calculated. The highest yield was obtained on galactose, while the yields were 5, 8, and 25% lower on lactose, GOS, and glucose, respectively. Therefore, a correspondence among ethanol production, low ATP yields, and low biomass production was established, demonstrating that carbohydrate preferences may result from different distributions of carbon fluxes through the fermentative pathway. During the fermentation of a GOS mixture, substrate selectivity based on the degree of polymerization was exhibited, since lactose and the trisaccharide were the first to be consumed, while a delay was observed until longer oligosaccharides were utilized. Throughout the growth on both lactose and GOS, galactose accumulated in the cultural broth, suggesting that β(1-4) galactosides can be hydrolyzed before they are taken up.

Ethanol Production from Lignocellulosic Biomass Using Xylotrophic Basidiomycetes

2015 ◽  
Vol 51 (5) ◽  
pp. 516-525 ◽  
Author(s):  
N. R. Al’myasheva ◽  
A. A. Novikov ◽  
E. Yu. Kozhevnikova ◽  
A. V. Golyshkin ◽  
A. V. Barkov ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Xylotrophic Basidiomycetes

scholarly journals Bio-ethanol (2nd Generation Ethanol): A Solution to Ever Polluting Gasoline to Climate in India

2020 ◽  
pp. 1-15
Author(s):  
Shruti Mohapatra ◽  
Raj Kishore Mishra ◽  
Khitish K. Sarangi
Keyword(s):  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Fossil Fuels ◽  
Economic Benefits ◽  
Policy Implications ◽  
Current Status ◽  
Environmentally Sustainable ◽  
2Nd Generation ◽  
Production Technologies ◽  
Rapid Pace

Environmentally sustainable energy sources are called for due to contemporaneous development in industries along with the rapid pace of urbanization. Ethanol produced from biomass can be deliberated as a clean and safest liquid fuel and an alternative to fossil fuels as they have provided unique environmental, strategic economic benefits. For the past decade, it has been noticed that there is an increasing trend found in bio ethanol production which has created a stimulus to go for advancement in bio ethanol production technologies. Several feed stocks have been used for the bio ethanol production but the second generation bio ethanol has concentrated on the lignocellulosic biomass. Plenteous lignocellulosic biomass in the world can be tapped for ethanol production, but it will require significant advances in the ethanol production process from lignocellulosic because of some technical and economic hurdles found in commercial scale. This review will encompass the current status of bio ethanol production in terms of their economic and environmental viability along with some research gaps as well as policy implications for the same.

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