Ethanol yield and sugar usability in thermophilic ethanol production from lignocellulose hydrolysate by genetically engineered Moorella thermoacetica

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.

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Hemicellulosic Bioethanol Production from Fast-Growing Paulownia Biomass

Processes ◽

10.3390/pr9010173 ◽

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.

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

Fermentation ◽

10.3390/fermentation5010016 ◽

2019 ◽

Vol 5 (1) ◽

pp. 16 ◽

Cited By ~ 5

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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POTENCIAL DE CLONES EXPERIMENTAIS DE BATATA-DOCE PARA PRODUÇÃO DE ETANOL

Nativa ◽

10.31413/nativa.v6i4.5613 ◽

2018 ◽

Vol 6 (4) ◽

pp. 352

Author(s):

Adriano Mendes Lourenço ◽

Aline Torquato Tavares ◽

Tiago Alves Ferreira ◽

Danilo Alves da Silva Porto Lopes ◽

João Victor Gonçalves Carline ◽

...

Keyword(s):

Ethanol Production ◽

Sweet Potato ◽

Ipomoea Batatas ◽

Ethanol Yield ◽

Starch Content ◽

Great Ability ◽

Ethanol Yields ◽

Root Starch ◽

Breeding Selection ◽

Starch Yield

A batata-doce (Ipomoea batatas (L.) Lam.) tem sido reportada como uma das espécies de planta com grande capacidade de converter biomassa em matéria prima para produção de etanol. O objetivo do trabalho foi avaliar o potencial de clones de batata-doce para produção de etanol. Foram avaliados 60 clones de batata-doce para produtividade de raízes, teor de amido nas raízes, produtividade de amido, coloração da casca e da polpa e o rendimento de etanol. O clone BDTO#122,32 e as cultivares Ana Clara e Carolina Vitória com média de 46,77; 42,75 e 41,25 t ha-¹, respectivamente, foram os que mais conseguiram acumular biomassa na forma de raiz. Os clones que apresentam as maiores médias de produtividade de amido por hectare foram BDTO#144.22 e BDTO#100.23, com valores de 15,46 e 14,16% t ha-1, com rendimentos de etanol de 8,33 e 7,63 m³ ha-¹. Os clones BDTO#144.22 e BDTO#100.23 apresentaram as maiores médias de produtividade de amido por hectare e rendimento de etanol, sendo, portanto, os mais promissores para a produção de etanol.Palavras-chave: Ipomoea batatas (L.) Lam, melhoramento genético, seleção, biocombustível. POTENTIAL OF EXPERIMENTAL CLONES OF SWEET POTATO FOR ETHANOL PRODUCTION ABSTRACT:Sweet potato (Ipomoea batatas (L.) Lam.) Has been reported as one of the plant species with great ability to convert biomass into feedstock for ethanol production. The objective of this work was to evaluate the potential of sweet potato clones for ethanol production. Twenty-six sweet potato clones were evaluated for root productivity, root starch content, starch yield, bark and pulp color, and ethanol yield. Clone BDTO # 122.32 and cultivars Ana Clara and Carolina Vitória averaging 46.77; 42.75 and 41.25 t ha-1, respectively, were the ones that were able to accumulate biomass in the root form. The clones presenting the highest starch productivity per hectare were BDTO # 144.22 and BDTO # 100.23, with values of 15.46 and 14.16% t ha-1, with ethanol yields of 8.33 and 7.63 m³ ha-¹. The clones BDTO # 144.22 and BDTO # 100.23 showed the highest averages of starch productivity per hectare and yield of ethanol, thus being the most promising for the production of ethanol.Keywords: Ipomoea potatoes (L.) Lam, breeding, selection, biofuel.

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Direct Ethanol Production from Lignocellulosic Sugars and Sugarcane Bagasse by a RecombinantTrichoderma reeseiStrain HJ48

The Scientific World JOURNAL ◽

10.1155/2014/798683 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Jun Huang ◽

Dong Chen ◽

Yutuo Wei ◽

Qingyan Wang ◽

Zhenchong Li ◽

...

Keyword(s):

Ethanol Production ◽

Trichoderma Reesei ◽

Sugarcane Bagasse ◽

Consolidated Bioprocessing ◽

Ethanol Yield ◽

Genome Shuffling ◽

Wild Type ◽

Mutant Population ◽

Ethanol Resistance ◽

Lignocellulosic Sugars

Trichoderma reeseican be considered as a candidate for consolidated bioprocessing (CBP) microorganism. However, its ethanol yield needs to be improved significantly. Here the ethanol production ofT. reeseiCICC 40360 was improved by genome shuffling while simultaneously enhancing the ethanol resistance. The initial mutant population was generated by nitrosoguanidine treatment of the spores, and an improved population producing more than fivefold ethanol than wild type was obtained by genome shuffling. The results show that the shuffled strain HJ48 can efficiently convert lignocellulosic sugars to ethanol under aerobic conditions. Furthermore, it was able to produce ethanol directly from sugarcane bagasse, demonstrating that the shuffled strain HJ48 is a suitable microorganism for consolidated bioprocessing.

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Expression of serpins by Clostridium thermocellum and simultaneous saccharification of lignocellulosic biomass to enhance ethanol production

BioResources ◽

10.15376/biores.15.4.8662-8676 ◽

2020 ◽

Vol 15 (4) ◽

pp. 8662-8676

Author(s):

Maria Mushtaq ◽

Muhammad Javaid Asad ◽

Muhammad Zeeshan Hyder ◽

Syed Muhammad Saqlan Naqvi ◽

Saad Imran Malik ◽

...

Keyword(s):

Ethanol Production ◽

Wheat Straw ◽

Corn Stover ◽

Rice Straw ◽

Clostridium Thermocellum ◽

Ethanol Yield ◽

Biofuel Production ◽

Yeast Fermentation ◽

Second Generation Bioethanol ◽

Simultaneous Saccharification

Utilization of biomass for production of second generation bioethanol was considered as a way to reduce burdens of fossil fuel in Pakistan. The materials wheat straw, rice straw, cotton stalk, corn stover, and peel wastes were used in this experiment. Various parameters, such as acidic and alkali pretreatment, enzymatic hydrolysis by cellulases, and effect of proteases inhibitors on ethanol production, were examined. Fermentation was completed by the yeasts Saccharomyces cerevisiae and Clostridium thermocellum separately, and their ethanol production were compared and maximum ethanol yield was obtained with wheat straw i.e.,11.3 g/L by S. cerevisiae and 8.5 g/L by C. thermocellum. Results indicated that a higher quantity of sugar was obtained from wheat straw (19.6 ± 1.6 g/L) followed by rice straw (17.6 ± 0.6 g/L) and corn stover (16.1 ± 0.9 g/L) compared to the other evaluated biomass samples. A higher yield of ethanol (11.3 g/L) was observed when a glucose concentration of 21.7 g/L was used, for which yeast fermentation efficiency was 92%. Results also revealed the increased in ethanol production (93%) by using celluases in combination with recombinant Serine protease inhibitors from C. thermocellum. It is expected that the use of recombinant serpins with cellulases will play a major role in the biofuel production by using agricultural biomass. This will also help in the economics of the biofuel.

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Effect of Various Pretreatment Methods on Bioethanol Production from Cotton Stalks

Fermentation ◽

10.3390/fermentation5010005 ◽

2019 ◽

Vol 5 (1) ◽

pp. 5 ◽

Cited By ~ 14

Author(s):

Konstantinos Dimos ◽

Thomas Paschos ◽

Argiro Louloudi ◽

Konstantinos G. Kalogiannis ◽

Angelos A. Lappas ◽

...

Keyword(s):

Ethanol Production ◽

Substrate Concentration ◽

Ethanol Yield ◽

Direct Conversion ◽

Hydrothermal Pretreatment ◽

Solid Loading ◽

Hydrolysis Time ◽

Cotton Stalks ◽

Sequential Combination ◽

Simultaneous Saccharification

Cotton stalks (CS) are considered a good candidate for fuel-ethanol production due to its abundance and high carbohydrate content, but the direct conversion without pretreatment always results in extremely low yields due to the recalcitrant nature of lignocelluloses. The present study was undertaken to investigate the effect of various chemical and physicochemical pretreatment methods, i.e., alkali, microwave-assisted acid, organosolv, hydrothermal treatment, and sequentially organosolv and hydrothermal pretreatment, on chemical composition of CS and subsequent ethanol production applying pre-hydrolysis and simultaneous saccharification and fermentation (PSSF) at high solid loading. The best results in terms of ethanol production were achieved by the sequential combination of organosolv and hydrothermal pretreatment (32.3 g/L, using 15% w/v substrate concentration and 6 h pre-hydrolysis) with an improvement of 32% to 50% in ethanol production compared to the other pretreatments. Extending pre-hydrolysis time to 14 h and increasing substrate concentration to 20% w/v, ethanol production reached 47.0 g/L (corresponding to an ethanol yield of 52%) after 30 h of fermentation.

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Investigation of the Feasibility and Feedstock Management Strategies of a Flexible Biomass to Ethanol Plant via Process Simulation

Volume 8: Engineering to Address Climate Change; Sustainable Products and Processes ◽

10.1115/imece2009-10494 ◽

2009 ◽

Author(s):

Nannan Kou ◽

Fu Zhao

Keyword(s):

Ethanol Production ◽

Alternative Energy ◽

Feeding Rate ◽

Ethanol Yield ◽

Management Strategies ◽

Chemical Conversion ◽

Wood Chips ◽

Production Model ◽

Wide Range ◽

Petroleum Oil

Current US transportation sector mainly relies on liquid hydrocarbon derived from petroleum oil and about 60% of the petroleum oil consumed is from areas where supply may be disturbed by regional instability. This has led to serious concerns on global warming and energy security. To address these issues, numerous alternative energy carriers have been proposed. Among them, second generation biofuel is one of the most promising technologies. Gasification based thermo-chemical conversion can utilize a wide range of biomass wastes and residues and bring flexibility to both feedstock and production sides of a plant, thus presents an attractive technical route. In this paper, a flexible feedstock thermo-chemical ethanol production process is investigated. This research focuses mainly on the evaluation of the feasibility of the process through numerical simulation. An existing thermo-chemical ethanol production model developed by NREL has been updated to handle the cases when different biomass feedstock and feedstock combinations are used. It is found that the ethanol yield is positively proportional to the feedstock feeding rate, while the total conversion efficiency is negatively proportional to the feeding rate. To demonstrate a feedstock management strategy, a plant located near a major city with a population of 200,000 and above is considered and MSW, legume straw and wood chips are selected as potential feedstock. Simulation results indicate that with wood chips as the backup feedstock the plant can be operated under extreme conditions when legume straw availability is significantly reduced without major equipment modification.

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Fuel Ethanol Production from Wet Oxidised Corn Stover by S. Cerevisiae

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.343-344.963 ◽

2011 ◽

Vol 343-344 ◽

pp. 963-967 ◽

Cited By ~ 1

Author(s):

Zhang Qiang ◽

Anne Belinda Thomsen

Keyword(s):

Ethanol Production ◽

Corn Stover ◽

Simultaneous Saccharification And Fermentation ◽

Ethanol Concentration ◽

Ethanol Yield ◽

Liquid Fraction ◽

Raw Material ◽

Wet Oxidation ◽

Inhibition Effect ◽

Simultaneous Saccharification

In order to find out appropriate process for ethanol production from corn stover, wet oxidation（195°C，15 minutes）and simultaneous sacchariﬁcation and fermentation (SSF) was carried out to produce ethanol. The results showed that the cellulose recovery of 92.9% and the hemicellulose recovery of 74.6% were obtained after pretreatment. 86.5% of cellulose was remained in the solid cake . After 24h hydrolysis at 50°C using cellulase（Cellubrix L）,the achieved conversion of cellulose to glucose was 64.8%. Ethanol production was evaluated from dried solid cake and the hydrolysate was employed as liquid fraction . After 142 h of SSF with substrate concentration of 8% (W/V), ethanol yield of 73.1 % of the theoretical based on glucose in the raw material was obtained by S. cerevisiae(ordinary baker’ yeast) . The corresponding ethanol concentration and volumetric productivity were 17.2g/L and 0.121g/L.h respectively. The estimated total ethanol production was 257.7 kg/ton raw material by assuming consumption of both C-6 and C-5. No obvious inhibition effect occurred during SSF. These instructions give you the basic guidelines for preparing papers for WCICA/IEEE conference proceedings.

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