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.

Fibrillating wood chips to facilitate high-valued lignin extraction and high titer ethanol production

2020 ◽  
Vol 146 ◽  
pp. 112153
Author(s):  
Yan Wu ◽  
Hairui Ji ◽  
Xingxiang Ji ◽  
Zhongjian Tian ◽  
Jiachuan Chen
Keyword(s):  
Ethanol Production ◽  
High Titer ◽  
Wood Chips ◽  
Lignin Extraction

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.

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.

Using a recyclable acid hydrotrope and subsequent short-term ultrasonic pretreatment to facilitate high-value lignin extraction and high-titer ethanol production

Cellulose ◽  
2020 ◽  
Vol 27 (13) ◽  
pp. 7561-7573
Author(s):  
Hairui Ji ◽  
Le Wang ◽  
Zhiqiang Pang ◽  
Wenyuan Zhu ◽  
Guihua Yang ◽  
...  
Keyword(s):  
Ethanol Production ◽  
High Titer ◽  
Short Term ◽  
Ultrasonic Pretreatment ◽  
Lignin Extraction

scholarly journals Sustainable 2G Ethanol Production From Switchgrass Biomass via Co-Fermentation of Pentoses and Hexoses Using Novel Wild Yeasts

2021 ◽  
Author(s):  
Felipe A. F. Antunes ◽  
Kalavathy Rajan ◽  
Angele Djioleu ◽  
Thiago M. Rocha ◽  
Larissa P. Brumano ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Ethanol Yield ◽  
Enzymatic Saccharification ◽  
Dilute Acid Pretreatment ◽  
Acid Pretreatment ◽  
Lignocellulosic Feedstock ◽  
Lignocellulosic Feedstocks ◽  
Wild Yeasts ◽  
Alkaline Delignification ◽  
Maximum Utilization

Abstract The production of second generation (2G) ethanol remains an interesting proposition for the implementation of sustainable and net carbon-neutral energy systems. 2G makes use of renewable lignocellulosic feedstocks, generating fermentable sugars that are converted to ethanol or other bio-based products. To be economically viable, 2G biorefineries must make use of all processing streams, including the less desirable C5 sugar stream. In this work, a strategy of sequential acid and alkaline pretreatment of the lignocellulosic feedstock switchgrass for improvement of fermentable sugar yield, and the subsequent utilization of wild yeasts for co-fermentation of its C5-C6 sugar streams are presented. Hemicellulose-enriched hydrolysates, obtained by dilute acid pretreatment of switchgrass, were fermented by a newly-isolated wild Scheffersomyces parashehatae strain–UFMG-HM-60.1b; corresponding ethanol yield (YPS) and volumetric productivity (QP) were 0.19 g/g and 0.16 g/L h, respectively. Afterwards, the remaining switchgrass cellulignin fraction was subjected to optimized alkaline delignification at 152 ºC for 30 min. The delignified solid fraction was subjected to contiguous enzymatic saccharification and fermentation, releasing a C6 sugar stream in which Saccharomyces cerevisiae 174 strain displayed a productivity of 0.46 g/g (YPS) and 0.70 g/L h (QP), whereas the S. parashehatae UFMG-HM-60.1b presented YPS and QP of 0.29 g/g and 0.38 g/L h, respectively. Upon combining the conversion of hemicellulose (37%) and cellulose-derived sugars (57%), the S. parashehatae strain provided higher yield (94%) than the generic S. cerevisiae (90%). Henceforth, our integrated pretreatment and co-fermentation process provides a pathway for maximum utilization of the switchgrass carbohydrates for 2G ethanol production.

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.

scholarly journals Enzymatic Process for Cystoseira barbata Valorization: Ethanol Production and Additional By-Products

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 741
Author(s):  
Doinita-Roxana Cioroiu Tirpan ◽  
Ancaelena Eliza Sterpu ◽  
Claudia Irina Koncsag ◽  
Alina Georgiana Ciufu ◽  
Tănase Dobre
Keyword(s):  
Ethanol Production ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Product Yield ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Cystoseira Barbata ◽  
Main Factors ◽  
Process Factors

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.

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.

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