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.

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

2011 ◽  
Vol 343-344 ◽  
pp. 963-967 ◽  
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.

scholarly journals Ethanol Production from Nondetoxified Dilute-Acid Lignocellulosic Hydrolysate by Cocultures of Saccharomyces cerevisiae Y5 and Pichia stipitis CBS6054

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ping Wan ◽  
Dongmei Zhai ◽  
Zhen Wang ◽  
Xiushan Yang ◽  
Shen Tian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Synthetic Medium ◽  
Pichia Stipitis ◽  
Dilute Acid ◽  
Acid Hydrolysate ◽  
Issatchenkia Orientalis ◽  
Final Ethanol Concentration

Saccharomyces cerevisiae Y5 (CGMCC no. 2660) and Issatchenkia orientalis Y4 (CGMCC no. 2159) were combined individually with Pichia stipitis CBS6054 to establish the cocultures of Y5 + CBS6054 and Y4 + CBS6054. The coculture Y5 + CBS6054 effectively metabolized furfural and HMF and converted xylose and glucose mixture to ethanol with ethanol concentration of 16.6 g/L and ethanol yield of 0.46 g ethanol/g sugar, corresponding to 91.2% of the maximal theoretical value in synthetic medium. Accordingly, the nondetoxified dilute-acid hydrolysate was used to produce ethanol by co-culture Y5 + CBS6054. The co-culture consumed glucose along with furfural and HMF completely in 12 h, and all xylose within 96 h, resulting in a final ethanol concentration of 27.4 g/L and ethanol yield of 0.43 g ethanol/g sugar, corresponding to 85.1% of the maximal theoretical value. The results indicated that the co-culture of Y5 + CBS6054 was a satisfying combination for ethanol production from non-detoxified dilute-acid lignocellulosic hydrolysates. This co-culture showed a promising prospect for industrial application.

Construction of Yeast Strain Capable of Co-Fermenting Pentose and Hexose by Protoplast Fusion

2013 ◽  
Vol 781-784 ◽  
pp. 847-851
Author(s):  
Jin Ling Guo ◽  
Da Chun Gong ◽  
Zhi Jun Li ◽  
Zhou Zheng
Keyword(s):  
Ethanol Production ◽  
Protoplast Fusion ◽  
Genetic Stability ◽  
Parental Strain ◽  
Conversion Rate ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Production Capacity ◽  
Pachysolen Tannophilus ◽  
Alcohol Conversion

Saccharomyces cerevisiae R40 and Pachysolen tannophilus P01 were used as the parental strain to construct an engineering strain capable of co-fermenting pentose and hexose by protoplast fusion. A fusant F202 was obtained through inactivating parental protoplasts, screening with YPX solid medium and high glucose liquid medium, ethanol production capacity detecting and identification with PCR-SSR technique. Subsequently, the fermentation performance and genetic stability of F202 was studied. The maximum ethanol production capacity from glucose was 1.47 ml/100 ml with a sugar and alcohol conversion rate 47% which was 11% higher than the parental strain P01. By fermenting xylose the ethanol concentration could achieve to 0.58 ml/100 ml with a sugar and alcohol conversion rate 12%. An ethanol concentration of 1.2 ml/100 ml was obtained by fermenting the mixture of xylose and glucose (mass ratio 1:2). Moreover, no decrease in ethanol yield after 8 generations propagation suggested fustant 202 possessed good genetic stability.

Construction and Evaluation of Recombinant Strains for Ethanol Production from Lignocellulosic Hydrolysate

2011 ◽  
Vol 347-353 ◽  
pp. 48-51 ◽  
Author(s):  
Shao Lan Zou ◽  
Chao Zhang ◽  
Yuan Yuan Ma ◽  
Le You ◽  
Min Hua Zhang
Keyword(s):  
Carbon Source ◽  
Ethanol Production ◽  
Rapid Growth ◽  
Sole Carbon Source ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Corn Straw ◽  
Lignocellulosic Hydrolysate ◽  
Preliminary Results ◽  
Theoretical Yield

The recombinant Z.mobilis CX was constructed. Its ethanol concentration and ethanol yield from 2% xylose at 36 h were 6.73 g/L and 82.3% of theoretical yield, respectively. The recombinant S.cerevisiae YB was constructed and was showed to utilize cellobiose as the sole carbon source for rapid growth and ethanol production. The maximum ethanol concentration 7.493 g/L and ethanol yield 77.4% of theoretical yield from 2% cellobiose were obtained at 24 h. Further, the preliminary results of SSF of pretreated corn straw demonstrated the potential of improving ethanol production and reducing the costs of cellose enzymes used by co-fermentation of CX and YB.

Improvement in Ethanol Yield from Lignocellulo-Starch Biomass using Saccharomyces cerevisiae alone or its Co-culture with Scheffersomyces stipitis

2020 ◽  
Vol 9 (1) ◽  
pp. 57-76
Author(s):  
Madhanamohanan G. Mithra ◽  
Gouri Padmaja
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Yield ◽  
Relative Advantage ◽  
Vegetable Crops ◽  
Fed Batch ◽  
Scheffersomyces Stipitis ◽  
Separate Hydrolysis And Fermentation ◽  
Ethanol Yields ◽  
Sugar Levels

Background: Literature on ethanol production from Lignocellulo-Starch Biomass (LCSB) containing starch besides cellulose and hemicellulose, is scanty. Fed-Batch Separate Hydrolysis And Fermentation (F-SHF) was earlier found more beneficial than Fed-Batch Simultaneous Saccharification and Fermentation (F-SSF). Objective: The study aimed at modification of the saccharification and fermentation strategies by including a prehydrolysis step prior to the SSF and compared the ethanol yields with co-culture fermentation using hexose-fermenting Saccharomyces cerevisiae and pentose-fermenting Scheffersomyces stipitis. Methods: Fed-batch hybrid-SSF and Fed-Batch Separate Hydrolysis and Co-culture Fermentation (F-SHCF) in improving ethanol yield from Steam (ST) or Dilute Sulfuric Acid (DSA) pretreated LCSBs (peels of root and vegetable crops) were studied. Results: There was a progressive build-up of ethanol during F-HSSF up to 72h and further production up to 120h was negligible, with no difference among pretreatments. Despite very high ethanol production in the initial 24h of fermentation by S.cerevisiae under F-SHCF, the further increase was negligible. A rapid hike in ethanol production was observed when S. stipitis was also supplemented because of xylose conversion to ethanol. Conclusion: While ST gave higher ethanol (296-323 ml/kg) than DSA under F-HSSF, the latter was advantageous under F-SHCF for certain residues. Prehydrolysis (24h; 50°C) enhanced initial sugar levels favouring fast fermentation and subsequent saccharification and fermentation occurred concurrently at 37°C for 120h, thus leading to energy saving and hence F-HSSF was advantageous. Owing to the low hemicellulose content in LCSBs, the relative advantage of co-culture fermentation over monoculture fermentation was not significant.

scholarly journals Two-Stage Aeration Fermentation Strategy to Improve Bioethanol Production by Scheffersomyces stipitis

Fermentation ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 97 ◽  
Author(s):  
Tiago Henriques ◽  
Susana Pereira ◽  
Luísa Serafim ◽  
Ana Xavier
Keyword(s):  
Ethanol Production ◽  
Ethanol Yield ◽  
Process Conditions ◽  
Agitation Rate ◽  
Bioethanol Production ◽  
Scheffersomyces Stipitis ◽  
Two Stage ◽  
Dissolved Oxygen Tension ◽  
Second Stage ◽  
Main Challenge

Hardwood spent sulfite liquor (HSSL) is a by-product from pulp industry with a high concentration of pentose sugars, besides some hexoses suitable for bioethanol production by Scheffersomyces stipitis. The establishment of optimal aeration process conditions that results in specific microaerophilic conditions required by S. stipitis is the main challenge for ethanol production. The present study aimed to improve the ethanol production from HSSL by S. stipitis through a two-stage aeration fermentation. Experiments with controlled dissolved oxygen tension (DOT) in the first stage and oxygen restriction in the second stage were carried out. The best results were obtained with DOT control at 50% in the first stage, where the increase of oxygen availability provided faster growth and higher biomass yield, and no oxygen supply with an agitation rate of 250 rpm, in the second stage allowed a successful induction of ethanol production. Fermentation using 60% of HSSL (v/v) as substrate for S. stipitis provided a maximum specific growth rate of 0.07 h−1, an ethanol productivity of 0.04 g L h−1 and an ethanol yield of 0.39 g g−1, respectively. This work showed a successful two-stage aeration strategy as a promising aeration alternative for bioethanol production from HSSL by S. stipitis.

scholarly journals Valorization of sunflower meal through the production of ethanol from the hemicellulosic fraction

2016 ◽  
Vol 20 (11) ◽  
pp. 1036-1042 ◽  
Author(s):  
Bruna Tavares ◽  
Luciane Sene ◽  
Divair Christ
Keyword(s):  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Sunflower Meal ◽  
Scheffersomyces Stipitis ◽  
Promising Alternative ◽  
Lignocellulosic Fibers ◽  
The World ◽  
Final Ethanol Concentration ◽  
Central Composite ◽  
By Products

ABSTRACT Sunflower is among the major oil seeds crop grown in the world and the by-products generated during the seeds processing represent an attractive source of lignocellulosic biomass for bioprocesses. The conversion of lignocellulosic fibers into fermentable sugars has been considered as a promising alternative to increase the demand for ethanol. The present study aimed to establish the fermentation conditions for ethanol production by Scheffersomyces stipitis ATCC 58376 in sunflower meal hemicellulosic hydrolysate, through a 23 CCRD (Central Composite Rotational Design) factorial design. Under the selected conditions (pH 5.25, 29 ºC and 198 rpm) the final ethanol concentration was 13.92 g L-1 and the ethanol yield was 0.49 g g-1.

scholarly journals Enhanced ethanol production from sugarcane molasses by industrially engineered Saccharomyces cerevisiae via replacement of the PHO4 gene

RSC Advances ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 2267-2276 ◽  
Author(s):  
Renzhi Wu ◽  
Dong Chen ◽  
Shuwei Cao ◽  
Zhilong Lu ◽  
Jun Huang ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Fermentation ◽  
Ethanol Yield ◽  
Regulatory Gene ◽  
Sugarcane Molasses ◽  
Fermentation Time ◽  
Fast Growing ◽  
Novel Strategy ◽  
Engineered Saccharomyces Cerevisiae

Replacement of a novel candidate ethanol fermentation-associated regulatory gene, PHO4, from a fast-growing strain through a novel strategy (SHPERM-bCGHR), is hypothesised to shorten fermentation time and enhance ethanol yield from sugarcane molasses.

scholarly journals Evaluation of Napier Grass for Bioethanol Production through a Fermentation Process

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 567 ◽  
Author(s):  
Mallika Boonmee Kongkeitkajorn ◽  
Chanpim Sae-Kuay ◽  
Alissara Reungsang
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Raw Materials ◽  
Napier Grass ◽  
Raw Material ◽  
Pennisetum Purpureum ◽  
Energy Crop ◽  
Tropical Regions ◽  
Filter Paper Unit ◽  
Enzyme Dosage

Ethanol is one of the widely used liquid biofuels in the world. The move from sugar-based production into the second-generation, lignocellulosic-based production has been of interest due to an abundance of these non-edible raw materials. This study interested in the use of Napier grass (Pennisetum purpureum Schumach), a common fodder in tropical regions and is considered an energy crop, for ethanol production. In this study, we aim to evaluate the ethanol production potential from the grass and to suggest a production process based on the results obtained from the study. Pretreatments of the grass by alkali, dilute acid, and their combination prepared the grass for further hydrolysis by commercial cellulase (Cellic® CTec2). Separate hydrolysis and fermentation (SHF), and simultaneous saccharification and fermentation (SSF) techniques were investigated in ethanol production using Saccharomyces cerevisiae and Scheffersomyces shehatae, a xylose-fermenting yeast. Pretreating 15% w/v Napier grass with 1.99 M NaOH at 95.7 °C for 116 min was the best condition to prepare the grass for further enzymatic hydrolysis using the enzyme dosage of 40 Filter Paper Unit (FPU)/g for 117 h. Fermentation of enzymatic hydrolysate by S. cerevisiae via SHF resulted in the best ethanol production of 187.4 g/kg of Napier grass at 44.7 g/L ethanol concentration. The results indicated that Napier grass is a promising lignocellulosic raw material that could serve a fermentation with high ethanol concentration.

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