scholarly journals Potential of Candida glabrata from ragi as a bioethanol producer using selected carbohydrate substrates

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Micky Vincent ◽  
Queentety Johnny ◽  
Dayang Salwani Awang Adeni ◽  
Nurashikin Suhaili
Keyword(s):  
Ethanol Production ◽  
Candida Glabrata ◽  
Ethanol Yield ◽  
Fermented Food ◽  
Ethanol Conversion ◽  
Ethanolic Fermentation ◽  
Different Types ◽  
Notable Increase ◽  
Theoretical Ethanol Yield ◽  
Simultaneous Saccharification

Abstract. Vincent M, Johnny Q, Adeni DSA, Suhaili N. 2020. Potential of Candida glabrata from ragi as a bioethanol producer using selected carbohydrate substrates. Nusantara Bioscience 12: 1-10. The flexibility and efficiency of fermenting microorganisms to convert substrates to ethanol are important factors in achieving high bioethanol yields during ethanolic fermentation. In this study, Candida glabrata, a common yeast found in fermented food, was evaluated in terms of its capability to produce ethanol using different types of carbohydrates, which included simple saccharides (glucose, maltose, sucrose), polysaccharides (starch and cellulose) and complex carbohydrates (total sago effluent, TSE). Our results indicated that C. glabrata was able to efficiently produce ethanol from glucose at 79.84% TEY (Theoretical Ethanol Yield). The ethanol production from sucrose was low, which was only 6.44% TEY, while no ethanol was produced from maltose. Meanwhile, for complex carbohydrate substrates such as starch and cellulose, ethanol was produced only when supplementary enzymes were introduced. Simultaneous Saccharification and Fermentation (SSF) of starch dosed with amylases resulted in an ethanol yield of 55.08% TEY, whilst SSF of cellulose dosed with cellulases yielded a TEY of 31.41%. When SSF was performed on TSE dosed with amylases and cellulases, the highest ethanol production was recorded within 24 h, with a yield of 23.36% TEY. Lactic acid and acetic acid were found to be at minimal levels throughout the fermentation period, indicating an efficient ethanol conversion. A notable increase in C. glabrata biomass was observed in cultures fed with glucose, starch (with supplementary amylases), and TSE (with supplementary amylases and cellulases). The current study indicates that C. glabrata can be used for bioethanol production from glucose, polysaccharides, and complex starchy lignocellulosic substrates such as TSE via SSF.

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

BioResources ◽  
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.

scholarly journals Effect of Various Pretreatment Methods on Bioethanol Production from Cotton Stalks

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 5 ◽  
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.

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 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 Response Surface ‎Methodology for Optimization of Ethanol ‎Production from Cocoa Waste

2020 ◽  
Vol 1 (1) ◽  
pp. 7-12
Keyword(s):  
Response Surface Methodology ◽  
Ethanol Production ◽  
Response Surface ◽  
Simultaneous Saccharification And Fermentation ◽  
Inoculum Size ◽  
Fermented Food ◽  
Optimum Conditions ◽  
Anova Analysis ◽  
Full Factorial ◽  
Simultaneous Saccharification

Cocoa waste (CW) is an inexpensive agro-industrial by-product that is available in large quantities in tropical countries such as Malaysia. The rate of ethanol production can be affected by different parameters involved during fermentation. In this study, response surface methodology (RSM) with the full factorial design was used to obtain optimum conditions for bioethanol production using CW as the substrate. The simultaneous saccharification and fermentation (SSF) performed with an isolated microorganism from locally fermented food tapai ubi and tapai pulut. The effect of four independent variables temperature, CW concentration, inoculum size, and pH was investigated. In the optimized condition temperature of 31.7°C, pH 6.0, inoculum size 10.5%, and CW concentration 0.3 g/L, the highest ethanol production was 9.5 ± 1.1. ANOVA analysis revealed that temperature and CW concentration had the most significant effects on ethanol production. In addition, ethanol production was increased in the highest level of pH and inoculum size. Therefore it can be concluded that ethanol production increased from 6.2 ± 0.8 g/L to 9.5 ± 1.1 g/L after optimization.

Proper ultrasound treatment increases ethanol production from simultaneous saccharification and fermentation of sugarcane bagasse

RSC Advances ◽  
2016 ◽  
Vol 6 (94) ◽  
pp. 91409-91419 ◽  
Author(s):  
Rajendran Velmurugan ◽  
Aran Incharoensakdi
Keyword(s):  
Ethanol Production ◽  
Sugarcane Bagasse ◽  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Yield ◽  
Ultrasound Treatment ◽  
Fermentation Processes ◽  
Cellulase Complex ◽  
Simultaneous Saccharification

To improve the saccharification and fermentation processes, proper ultrasound was applied which resulted in the presence of cellulase complex with improved β-glucosidase ratio leading to enhanced overall ethanol yield.

scholarly journals Production of bioethanol from sago hampas via Simultaneous Saccharification and Fermentation (SSF)

2018 ◽  
Vol 10 (4) ◽  
pp. 240-245 ◽  
Author(s):  
HUANG CHAI HUNG ◽  
DAYANG SALWANI AWANG ADENI ◽  
QUEENTETY JOHNNY ◽  
MICKY VINCENT
Keyword(s):  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Yield ◽  
Cellulolytic Enzymes ◽  
Total Biomass ◽  
Bioethanol Production ◽  
Amylolytic Enzymes ◽  
Theoretical Ethanol Yield ◽  
Waste Accumulation ◽  
Biomass Reduction ◽  
Simultaneous Saccharification

Huang CH, Adeni DSA, Johnny Q, Vincent M. 2018. Production of bioethanol from sago hampas via Simultaneous Saccharification and Fermentation (SSF). Nusantara Bioscience 10: 240-245. Sago hampas is an inexpensive, renewable and abundant agro-industrial residue that can be exploited to produce bioethanol. In this study, ethanol production was performed via simultaneous saccharification and fermentation (SSF) on fresh sago hampas at 2.5%, 5.0% and 7.5% (w/v) feedstock loadings with the aid of amylolytic enzymes, cellulolytic enzymes and Saccharomyces cerevisiae, under anaerobic condition for five days with a constant agitation of 150 rpm and ambient temperature. Results obtained indicated that SSF with 5.0% (w/v) sago hampas loading produced the highest ethanol yield at 17.79 g/L (79.65% Theoretical Ethanol Yield, TEY), while SSF using 2.5% and 7.5% (w/v) sago hampas produced ethanol at only 8.38 g/L (75.00% TEY) and 23.28 g/L (69.48% TEY), respectively. Total biomass reduction was recorded between 66.3% to 71.3% by the end of the SSF period. This study demonstrated that fresh sago hampas is a promising feedstock for bioethanol production as yields are generally high for all the substrate loadings tested. Moreover, bioethanol production using fresh sago hampas may assist in reducing pollution caused by sago waste accumulation.

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 Kinetic modeling of simultaneous saccharification and fermentation of corn starch for ethanol production.

2014 ◽  
Vol 61 (1) ◽  
Author(s):  
Wojciech Białas ◽  
Adrian Czerniak ◽  
Daria Szymanowska-Powałowska
Keyword(s):  
Central Composite Design ◽  
Ethanol Production ◽  
Corn Starch ◽  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Yield ◽  
Kinetics Model ◽  
Ssf Process ◽  
Central Composite ◽  
Simultaneous Saccharification ◽  
Granular Starch

Fuel ethanol production, using a simultaneous saccharification and fermentation process (SSF) of native starch from corn flour, has been performed using Saccharomyces cerevisiae and a granular starch hydrolyzing enzyme. The quantitative effects of mash concentration, enzyme dose and pH were investigated with the use of a Box-Wilson central composite design protocol. Proceeding from results obtained in optimal fermentation conditions, a kinetics model relating the utilization rates of starch and glucose as well as the production rates of ethanol and biomass was tested. Moreover, scanning electron microscopy (SEM) was applied to investigate corn starch granule surface after the SFF process. A maximum ethanol concentration of 110.36 g/l was obtained for native corn starch using a mash concentration of 25%, which resulted in ethanol yield of 85.71%. The optimal conditions for the above yield were found with an enzyme dose of 2.05 ml/kg and pH of 5.0. These results indicate that by using a central composite design, it is possible to determine optimal values of the fermentation parameters for maximum ethanol production. The investigated kinetics model can be used to describe SSF process conducted with granular starch hydrolyzing enzymes. The SEM micrographs reveal randomly distributed holes on the surface of granules.

scholarly journals A Hydrotrope Pretreatment for Stabilized Lignin Extraction and High Titer Ethanol Production

2022 ◽  
Author(s):  
Hairui Ji ◽  
Le Wang ◽  
Furong Tao ◽  
Zhipeng Yao ◽  
Xuezhi Li ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Ethanol Yield ◽  
High Titer ◽  
Enzymatic Saccharification ◽  
Value Added ◽  
Enzymatic Digestion ◽  
Lignin Extraction ◽  
C 30 ◽  
Theoretical Ethanol Yield ◽  
Light Color

Abstract The biomass pretreatment strategies using organic acids facilitate lignin removal and enhance the enzymatic digestion of cellulose. However, lignin always suffers a severe and irreversible condensation. The newly generated C-C bonds dramatically affect its further upgrading. In this study, we used a recyclable hydrotrope (p-Toluenessulfonic acid, p-TsOH) to dissolve lignin under mild condition and stabilized lignin with a quenching agent (formaldehyde, FA) during extraction, achieving both value-added lignin extraction and efficient enzymatic saccharification of cellulose. Approximately 63.7% of lignin was dissolved by 80% (wt. %) p-TsOH with 1.5% FA addition at 80 o C, 30 min. The obtained lignin was characterized by FTIR spectroscopy, TGA, 2D HSQC NMR spectroscopy, and GPC. The results indicated that the extracted lignin exhibited excellent properties, such as light color, a low molecular weight (Mw, 5371 g/mol), and a narrow polydispersity (Mw/Mn, 1.63). The pretreated substrate was converted to ethanol via a quasi-simultaneous saccharification and fermentation process (Q-SSF). After fermentation of 60 h, the ethanol concentration reached 38.7±3.3 g/L which was equivalent to a theoretical ethanol yield of 82.9±2.2% based on the glucan content, while the residual glucose concentration was only 4.69±1.4 g/L. In short, this pretreatment strategy protected lignin to form new C-C linkages and improved the enzymatic saccharification of glucan for high-titer ethanol production.

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