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.

scholarly journals Deacetylation Followed by Fractionation of Yellow Poplar Sawdust for the Production of Toxicity-Reduced Hemicellulosic Sugar for Ethanol Fermentation

2018 ◽  
Author(s):  
Seong Ju Kim ◽  
Tae Hyun Kim ◽  
Kyeong Keun Oh
Keyword(s):  
Ethanol Production ◽  
Ethanol Yield ◽  
Alkali Treatment ◽  
Pichia Stipitis ◽  
Ammonia Solution ◽  
Dilute Acid ◽  
Yellow Poplar ◽  
Theoretical Ethanol Yield ◽  
Optimized Conditions ◽  
Poplar Sawdust

In order to produce bioethanol from yellow poplar sawdust without detoxification, deacetylation (mild alkali treatment) was performed with aqueous ammonia solution. To select the optimal conditions, deacetylation process was carried out using different conditions: NH4OH loading (2–10% (w/v)) and solid-to-liquid ratio (1:4–10) at 121 °C for 60 min. In order to assess the effectiveness of deacetylation, fractionation of deacetylated yellow poplar sawdust was performed using dilute acid (H2SO4, 0.5–2.0% (w/v)), reaction temperature (130–150 °C) and time (10–80 min). The toxicity-reduced hemicellulosic hydrolysates that were obtained through a two-step treatment at optimized conditions were fermented using Pichia stipitis for ethanol production, without any further detoxification. The maximum ethanol production was 4.84 g/L, corresponding to a theoretical ethanol yield of 82.52%, which is comparable to those of intentionally made hydrolyzates as controls.

scholarly journals Co-culture of Saccharomyces cerevisiae (VS3) and Pichia stipitis (NCIM 3498) for bioethanol production using concentrated Prosopis juliflora acid hydrolysate

2019 ◽  
Author(s):  
Shaik Naseeruddin ◽  
Suseelendra Desai ◽  
L Venkateswar Rao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Yield ◽  
Culture Method ◽  
Pichia Stipitis ◽  
Prosopis Juliflora ◽  
Bioethanol Production ◽  
Dilute Acid Hydrolysis ◽  
Total Carbohydrate ◽  
Fermentation Efficiency ◽  
Acid Hydrolysate

AbstractBioethanol production from lignocellulosic biomass is a viable option for improving energy security and reducing green house emissions. In the present study Prosopis juliflora, an invasive tree found through out India, with total carbohydrate content of 67.4 +/- 6% was selected as lignocellulosic feedstock for bioethanol production. The hydrolysate obtained after biphasic dilute acid hydrolysis contained initial sugar concentration of 18.70 +/- 0.16 g/L and hence to increase the ethanol yield it was concentrated to 33.59 +/- 0.52 g/L (about two-folds) by vacuum distillation. The concentration of sugars, phenols and furans was analyzed before and after concentration process. The concentrated hydrolysate was further detoxified by over liming, neutralization and charcoal treatment and later used for ethanol fermentation by mono- and co culture method. Monoculture of Saccharomyces cerevisiae (VS3) and Pichia stipitis (NCIM 3498) produced 8.52 +/- 0.43 and 4.52 +/- 0.23 g/L of ethanol with 66.21 +/- 3.26% and 60.46 +/- 3.02% of fermentation efficiency, 0.33 +/- 0.02 and 0.31 +/- 0.02 g/g of ethanol yield and 0.24 +/- 0.01 and 0.13 +/- 0.01 g/L/h of productivity, respectively. The co-culture of S. cerevisiae (VS3) and P. stipitis (NCIM 3498) helped to improve all parameters i.e. 10.94 +/- 0.53 g/L of ethanol with fermentation efficiency, ethanol yield and productivity of 83.11 +/- 0.42%, 0.420 +/- 0.01 g/g and 0.30 +/- 0.01 g/L/h, respectively.

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 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.

scholarly journals Food Grade Ethanol Production Process of Sorghum Stem Juice Using Immobilized Cells Technique

2015 ◽  
Vol 9 (7) ◽  
pp. 8 ◽  
Author(s):  
Tri Widjaja ◽  
Ali Altway ◽  
Arief Widjaja ◽  
Umi Rofiqah ◽  
Rr Whiny Hardiyati Erlian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Sieve ◽  
Zymomonas Mobilis ◽  
Immobilized Cells ◽  
Ethanol Yield ◽  
Continuous Fermentation ◽  
Continuous Process ◽  
Pichia Stipitis ◽  
Batch Process ◽  
Food Grade

One form of economic development efforts for waste utilization in rural communities is to utilize stem sorghum to produce food grade ethanol. Sorghum stem juice with 150 g/L of sugar concentration was fermented using conventional batch process and cell immobilization continuous process with K-carrageenan as a supporting matrix. The microorganism used was Mutated Zymomonas Mobilis to be compared with a mixture of Saccharomyces Cerevisiae and Pichia Stipitis, and a mixture of Mutated Zymomonas Mobilis and Pichia Stipitis. Ethanol in the broth, result of fermentation process, was separated in packed distillation column. Distilate of the column, still contain water and other impurities, was flown into molecular sieve for dehydration and activated carbon adsorption column to remove the other impurities to meet food grade ethanol specification. The packing used in distillation process was steel wool. For batch fermentation, the fermentation using a combination of Saccharomyces Cerevisiae and Pichia Stipitis produced the best ethanol with 12.07% of concentration, where the yield and the productivity were 63.49%, and 1.06 g/L.h, respectively. And for continuous fermentation, the best ethanol with 9.02% of concentration, where the yield and the productivity were 47.42% and 174.27 g/L.h, respectively, is obtained from fermentation using a combination of Saccharomyces Cerevisiae and Pichia Stipitis also. Fermentation using combination microorganism of Saccharomyces Cerevisiae and Pichia Stipitis produced higher concentration of ethanol, yield, and productivity than other microorganisms. Distillation, molecular sieve dehydration and adsorption process is quite successful in generating sufficient levels of ethanol with relatively low amount of impurities.

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 ATPase-based implementation of enforced ATP wasting in Saccharomyces cerevisiae for improved ethanol production

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ahmed Zahoor ◽  
Katrin Messerschmidt ◽  
Simon Boecker ◽  
Steffen Klamt
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Atpase Activity ◽  
Ethanol Production ◽  
Ethanol Yield ◽  
Volumetric Productivity ◽  
Anaerobic Growth ◽  
Control Strain ◽  
Genomic Integration ◽  
Expression Of Genes ◽  
Atp Generation

Abstract Background Enforced ATP wasting has been recognized as a promising metabolic engineering strategy to enhance the microbial production of metabolites that are coupled to ATP generation. It also appears to be a suitable approach to improve production of ethanol by Saccharomyces cerevisiae. In the present study, we constructed different S. cerevisiae strains with heterologous expression of genes of the ATP-hydrolyzing F1-part of the ATPase enzyme to induce enforced ATP wasting and quantify the resulting effect on biomass and ethanol formation. Results In contrast to genomic integration, we found that episomal expression of the αβγ subunits of the F1-ATPase genes of Escherichia coli in S. cerevisiae resulted in significantly increased ATPase activity, while neither genomic integration nor episomal expression of the β subunit from Trichoderma reesei could enhance ATPase activity. When grown in minimal medium under anaerobic growth-coupled conditions, the strains expressing E. coli’s F1-ATPase genes showed significantly improved ethanol yield (increase of 10% compared to the control strain). However, elevated product formation reduces biomass formation and, therefore, volumetric productivity. We demonstrate that this negative effect can be overcome under growth-decoupled (nitrogen-starved) operation with high and constant biomass concentration. Under these conditions, which mimic the second (production) phase of a two-stage fermentation process, the ATPase-expressing strains showed significant improvement in volumetric productivity (up to 111%) compared to the control strain. Conclusions Our study shows that expression of genes of the F1-portion of E. coli’s ATPase induces ATPase activity in S. cerevisiae and can be a promising way to improve ethanol production. This ATP-wasting strategy can be easily applied to other metabolites of interest, whose formation is coupled to ATP generation.

Bioethanol Production from Pineapple Peel Juice Using Saccharomyces cerevisiae

2014 ◽  
Vol 875-877 ◽  
pp. 242-245
Author(s):  
Jutarut Pornpunyapat ◽  
Wilaiwan Chotigeat ◽  
Pakamas Chetpattananondh
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Concentration ◽  
Renewable Resource ◽  
Reducing Sugar ◽  
Total Sugar ◽  
Bioethanol Production ◽  
Pineapple Peel ◽  
Initial Ph ◽  
Production Characteristics

Bioethanol is widely used as renewable resource due to its safe to produce and environmentally friendly. However, knowledge on ethanol production from pineapple peel juice (Pattawia spp) is far from sufficient. In this work, pineapple peel juice (initial pH at 5) was fermented at various yeast contents (1, 3 and 5% by wt.) and fermentation times (3, 5 and 7 days) in order to investigate ethanol production characteristics. Yeast, Sacchromyces cerevisiae was grown on pineapple peel juice. The squeezed juice contained 11% of total sugar and 5% of reducing sugar. The results indicated that the optimum ethanol production was yeast contents of 5% by wt. and fermentation times of 5 days which gave the ethanol production of 9.08g/l. The ethanol at a higher yeast content also had a higher ethanol concentration.

Ethanol Production from Different Substrates by a Flocculent Saccharomyces cerevisiae Strain

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
José Duarte ◽  
Vera Lourenço ◽  
Belina Ribeiro ◽  
Maria Céu Saagua ◽  
Joana Pereira ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Yeast Strain ◽  
Fossil Fuels ◽  
Ethanol Yield ◽  
Corn Fiber ◽  
Production Costs ◽  
Raw Material ◽  
Continuous Reactor ◽  
Different Strains

During the last years there has been an increasing interest in using ethanol as a substitute for fossil fuels. The bioethanol used today is mainly produced from sugar cane and cereals, but reducing the production costs of ethanol is still crucial for a viable economic process. Cellulose from vegetable biomass will be the next cheap raw material for second generation fuel ethanol production and agricultural by-products with a low commercial value, as corn stover, corn fiber and cane bagasses would become an attractive feedstock for bioethanol production.In this study, different strains of Saccharomyces cerevisiae have been screened for the ability of bioethanol production. Yeasts were grown in a synthetic liquid medium containing sucrose in batch regime and the growth rates, ethanol and biomass productions were determined as well as their growth ability in cane molasses.The results indicate that a flocculent yeast, isolated in our lab and designated by strain F, was the most promising yeast strain among those tested for continuous ethanol production. This strain was isolated from corn hydrolysates, obtained from a Portuguese distillery facility (DVT, Torres Novas, Portugal) showing highest growth rate (0.49h-1), highest ethanol yield (0.35g/g) and high flocculation capacity.The study on ethanol production in continuous reactor process with the selected yeast strain (strain F) was made on sucrose and cane molasses at different dilution rates (0.05-0.42 h-1). A steady flocculating yeast fluidized bed reactor system was established allowing the functioning of the reactor for 1000 h. Data shows that when the dilution rate rose to 0.42h-1, the highest productivity (20g/Lh) was obtained attaining an ethanol concentration in the reactor of 47g/L for sucrose and molasses media.

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