scholarly journals Facilely reducing recalcitrance of lignocellulosic biomass by a newly developed ethylamine based deep eutectic solvent for biobutanol fermentation

2020 ◽  
Author(s):  
Guochao Xu ◽  
Hao Li ◽  
Wanru Xing ◽  
Lei Gong ◽  
Jinjun Dong ◽  
...  

Abstract Background: Biobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation.Results: Several DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars of as high as 53.5 g·L–1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU·g–1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g·L–1 and 706 g·kg–1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g·L–1 was achieved with butanol yield of 137 g·kg–1 pretreated corncob by Clostridium saccharobutylicum DSM13864.Conclusions: Ethylamine and lactic acid based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Guochao Xu ◽  
Hao Li ◽  
Wanru Xing ◽  
Lei Gong ◽  
Jinjun Dong ◽  
...  

Abstract Background Biobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation. Results Several DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars as high as 53.5 g L−1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU g−1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g L−1 and 706 g kg−1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g L−1 was achieved with butanol yield of 137 g kg−1 pretreated corncob by Clostridium saccharobutylicum DSM13864. Conclusions Ethylamine and lactic acid-based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.


2020 ◽  
Author(s):  
Guochao Xu ◽  
Hao Li ◽  
Wanru Xing ◽  
Lei Gong ◽  
Jinjun Dong ◽  
...  

Abstract Background: Biobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation.Results: Several DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars of as high as 53.5 g·L–1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU·g–1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g·L–1 and 706 g·kg–1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g·L–1 was achieved with butanol yield of 137 g·kg–1 pretreated corncob by Clostridium saccharobutylicum DSM13864.Conclusions: Ethylamine and lactic acid based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.


2020 ◽  
Vol 11 (3) ◽  
pp. 3017-3023
Author(s):  
Balakrishnan I ◽  
Jawahar N ◽  
Senthil Venkatachalam ◽  
Debosmita Datta

Eutectic mixture (EM) is as a mixture of more than one substance that does not interact individually to create a new entity but in a particular ratio that exhibits a lower range of melting point than it had in individual. EM should be formulated in such a way that it should have major advantages in pharmaceutical industries. EM can be a mixture of Active Pharmaceutical Ingredients (APIs), or different ratios of APIs and excipients, or various excipients. Deep eutectic solvents containing APIs (API-DES) considered as an innovative approach to form different APIs in the liquid state. This new approach of liquid form is versatile and plays an important role in drug delivery. The selection of ideal hydrogen bond-donor (HBD) and hydrogen bond-acceptor (HBA) is an essential parameter. Ionic liquids (IL), derivatives of deep eutectic solvents (DES) have got much attention since it can replace harmful organic solvent by their extraordinary properties. Therapeutic deep eutectic solvents (THEDESs) are considered to be an exceptional option in the advancement of biomedicine. This can be utilized for improvising drug solubility, bioavailability as well as drug permeation through the skin. Natural deep eutectic solvent (NADES) can be considered as an alternate option, replacing harsh solvents. It has special characteristics of better biodegradability and biocompatibility. These NADES mainly used to separate and purification of natural compounds. This review focuses on the eutectic mixture and its application in the area of drug delivery systems, and pharmaceutical and pharmacological fields.


2020 ◽  
Vol 58 (9) ◽  
pp. 880-886
Author(s):  
Xiao Li ◽  
Tao Yuan ◽  
Ting Zhao ◽  
Xiaomei Wu ◽  
Yaling Yang

Abstract An environmentally friendly method for the determination of testosterone and methyltestosterone by acid–base-induced deep eutectic solvents liquid–liquid microextraction (DES-ABLLME) combining with high-performance liquid chromatography was established. The deep eutectic solvent (DES) consisting of menthol:lauric acid:decanoic acid (3:1:1) can act as both hydrogen bond donor and hydrogen bond acceptor. In this approach, ammonia solution (NH3•H2O) is used as an emulsifier to react with DESs in the extraction process to generate salt and form milky white solution, achieving high extraction efficiency. Hydrochloric acid was used as a phase separator to change the emulsification state and promote the separation of extraction agent from water phase. A series of parameters were optimized including the volume of DES and the emulsifying agent, glucose concentration as well as hydrochloric acid volume. The method was linear in the range 0.5–100 μg mL−1 with a correlation coefficient (R) of 0.9999, and the limits of detection were 0.067 and 0.2 μg mL−1 for testosterone and methyltestosterone, respectively. This method was applied to analyze testosterone and methyltestosterone in milk samples, and the recoveries were between 89.2 and 108.2%.


2009 ◽  
Vol 62 (4) ◽  
pp. 341 ◽  
Author(s):  
Andrew P. Abbott ◽  
John Collins ◽  
Ian Dalrymple ◽  
Robert C. Harris ◽  
Reena Mistry ◽  
...  

The present paper describes the design and operation of the first large-scale extraction and separation of metals from a complex matrix using an ionic liquid. The liquid was a deep eutectic solvent based on choline chloride. The hydrogen-bond donors were mixed to optimize solubility and fluid viscosity. It was found that the incorporation of a fine particulate dust actually decreased the viscosity of the fluid. The present paper shows that selective extraction of zinc and lead can be achieved through judicious choice of the hydrogen-bond donor and it is also shown that metals in solution can be separated using cementation with zinc powder. Electrowinning of pure zinc is demonstrated but scale-up tests suggest that the process is relatively slow and has poor current efficiency. An alternative methodology was developed to rapidly recover the zinc from solution using dilute ammonia solution. It is also shown for the first time that cementation can be efficiently carried out in ionic liquids because the recovered metal is porous and allows thick layers to be deposited.


2020 ◽  
Author(s):  
◽  
Chip Joseph II Smith

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI--COLUMBIA AT REQUEST OF AUTHOR.] Pollutants have become more prevalent in the air, water, and ground, necessitating the development of technologies that would help, limit, reverse, monitor, measure, and recycle prevalent pollutants. Ionic liquids (ILs), or molten salts that are liquid at or below 100[degrees]C, as well as deep eutectic solvents (DESs), a mixture of a hydrogen bond donor with a strong hydrogen bond acceptor that remains liquid upon cooling, have been popularized as greener alternatives in industry. These liquids tend to have large electrochemical and thermal windows, a very small vapor pressure, and can be fine-tuned for many applications. The liquid state of ILs and DESs makes them quite useful in their application but complicates their handling. Ionogels and eutectogels enable the liquid-like dynamics of these solvents while adding a pseudo-solid like character that makes for ease of handling. Herein, a new group of confined ILs and DESs within a cellulosic matrix called bacterial cellulose iono/eutecto gels are produced that are shown to be applicable to analyte detection and are studied for a better understanding of the dynamics within the gel. These intriguing gels are flexible, transparent, size-tuneable, shape-tuneable, amenable to incorporation of dyes or other functional material, and capable of confining 99 wt.% of a solvent with little leakage from the gel. These materials affect the crystallinity of cellulose little, while the liquid presents a diffusional change that stems from restructuring of the fluid. These gels are capable of detection of ammonia, hydrogen sulfide, and temperature. Given their properties, iono/eutecto gels offer use in applications, such as electrochemical devices, wound healing, drug delivery, and carbon capture/separation membranes.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2157 ◽  
Author(s):  
Paulo Torres ◽  
Mercè Balcells ◽  
Enrique Cequier ◽  
Ramon Canela-Garayoa

Using the basic principle of construction between a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD), four bio-based deep eutectic solvents (DESs) were prepared in a 1:2 molar ratio of HBA:HBD. 2,3-Dihydroxypropyl-1-triethylammonium chloride ([C9H22N+O2]Cl−) was synthesized from raw glycerol and used as an HBA. Lactic acid, urea, pure glycerol, and ethylene glycol were selected as HBD. Attempts to prepare DESs, using citric acid and benzoic acid as HBDs, were unsuccessful. All these DESs were characterized using FTIR and NMR techniques. Besides, physicochemical parameters such as pH, viscosity, density, and melting point were determined. The behavior of these DES to fractionate olive pomace was studied. Lignin recovery yields spanned between 27% and 39% (w/w) of the available lignin in olive pomace. The best DES, in terms of lignin yield ([C9H22N+O2]Cl− -lactic acid), was selected to perform a scale-up lignin extraction using 40 g of olive pomace. Lignin recovery on the multigram scale was similar to the mg scale (38% w/w). Similarly, for the holocellulose-rich fractions, recovery yields were 34% and 45% for mg and multi-gram scale, respectively. Finally, this DES was used to fractionate four fruit pruning samples. These results show that our novel DESs are alternative approaches to the ionic liquid:triethylammonium hydrogen sulfate and the widely used DES: choline chloride:lactic acid (1:10 molar ratio) for biomass processing.


2017 ◽  
Author(s):  
◽  
Maryam Al Ameri

In this study, green solvent-based pretreatment was developed for improving the conversion of switchgrass to acetoin. Deep eutectic solvents (DESs), comprising choline chloride (ChCl) as a hydrogen-bond acceptor (HBA) and various chemical as a hydrogen-bond donor (HBD), were used to pretreat switchgrass. Different HBD groups, including polyalcohol, amid, diazole, and carboxylic acid, were used to synthesize DESs. The DESs using ChCl-formic acid and ChCl-lactic acid-acetic acid showed excellent performance in enhancing switchgrass digestibility. The obtained hydrolysate was successfully detoxified by using overliming detoxification, which was further used for acetoin fermentation by Bacillus licheniformis (NRRL B-642). The yield and titer of the produced acetoin were 0.377 g/g and 19.6 g/L, respectively. Our research demonstrates that DES pretreatment is an effective method for reducing biomass recalcitrance and improving the conversion of biomass into chemicals.


2021 ◽  
Vol 11 (6) ◽  
pp. 14620-14633

Turmeric contains curcumin as one of the active constituents, which gives yellow color and possesses lots of pharmacological actions. Even though curcumin has lots of pharmacological actions till now, it has not been approved as a medicine due to its low water solubility, permeability, and poor bioavailability. Deep eutectic solvent (DES) can be prepared by simply mixing two or more solid components, [among the two one is hydrogen bond donor (HBD) and another is hydrogen bond acceptor (HBA)] at a definite molar ratio where the solid components by self-association converted into a liquid at room temperature (RT). Natural deep eutectic solvents (NADES) are a specific subgroup of DES containing primary plant-based metabolites such as organic acids, alcohols, amino acids, or sugars. In this work, natural hydrophobic DESs were prepared with Camphor, Menthol, and Thymol. This was prepared from different ratios of Menthol:Thymol 1:1 to 1:5 and 1:1 to 5:1 (MT-DES); Camphor:Thymol 1:1 to 1:5 and 1:1 to 5:1 (CT-NADES); Camphor:Menthol 1:1 to 1:5 and 1:1 to 2:1 (CM-NADES). The pH and viscosity of prepared DESs were determined with the help of a digital pH meter and Brookfield viscometer. The solubility of curcumin in different NADESs was determined at room temperature (RT) to higher temperatures. The formation of different clear DES was obtained with slight heat. There was no difference in pH for the NADESs prepared without and with heat. Regarding the viscosity CM-DES (1:1) showed less viscosity when compared to other NADESs. The solubility of curcumin was found to be nearly double when it was dissolved in NADES for 1 hr at 35-40°C compared to 48 h stirring at 500 rotations per minute (rpm) at RT. Among different NADESs, curcumin solubility was found to be more in CM (1:1) ratio when compared to other NADESs.


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