Stability of cellulase in ionic liquids: correlations between enzyme activity and COSMO-RS descriptors

AbstractIonic liquids (ILs) are effective in pretreating cellulose for enhanced enzymatic saccharification, however ILs can inactivate cellulases. To guide the selection of ILs, the activity of cellulase was correlated with COSMO-RS calculations and descriptors of ILs including hydrogen bond (H-bond) basicity/acidity, polarity and ion size. Trends were deduced using an anion-series and a cation-series of ionic liquids in aqueous solutions. The activity in the cation-series was best correlated with the size of varied cations, whereas the activity in the anion-series showed a pronounced correlation to H-bond basicity and polarity of different anions. COSMO-RS was further used to predict the solubility of cellulose in ILs, which was correlated with cellulase activity on IL-pretreated cellulose. The best correlations were found between the enzyme activity in the anion-series ILs and the logarithmic activity coefficients, the H-bond energy, H-bond basicity and polarizability, underlining that the anion plays a crucial role in cellulose dissolution.

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Mutagenesis of Aspergillus aculeatus by 60Co-γ irradiation for high production of potential ILs-tolerant cellulase

BioResources ◽

10.15376/biores.15.3.6974-6988 ◽

2020 ◽

Vol 15 (3) ◽

pp. 6974-6988

Author(s):

Rui-Ping Xi ◽

Ye-Qiang Qi ◽

Bi-Xian Zhang ◽

Xin-Miao He ◽

He-Shu Chen ◽

...

Keyword(s):

Ionic Liquids ◽

Corn Stover ◽

Enzymatic Saccharification ◽

Cellulase Activity ◽

Cellulase Production ◽

Fungal Strain ◽

Γ Irradiation ◽

Aspergillus Aculeatus ◽

Mutant Strains ◽

High Production

Ionic liquids (ILs) are effective solvents for lignocellulose pretreatment. Enzymatic saccharification converts pretreated lignocelluloses into valuable products, and IL-tolerant cellulase improves the enzymatic efficiency and the reuse of ILs. In this study, a fungal strain with a relatively high cellulase production was isolated and identified as Aspergillus aculeatus G1-3. The high production of β-glucosidase (1.943 U per mL), CMCase (1.303 U per mL), and FPase (0.165 U per mL) was obtained using corn stover as the carbon source and peptone as the nitrogen source. The results were obtained at pH 8.0 and 30 °C with an inoculation size of 3% (volume per volume) for 7 days. A mutant strain Aspergillus aculeatus P6 with β-glucosidase (7.023 U per mL), CMCase (1.543 U per mL), and FPase (0.098 U per mL) was obtained by 60Co-γ irradiation. The cellulase activity was measured at pH 5.0 and 60 °C for enzymatic hydrolysis. The cellulase from mutant strains was stable in different concentrations of 1-ethyl-3-methylimidazolium acetate. Enzymatic saccharification of the original corn stover and ILs-pretreated corn stover was successfully performed with high sugar yields. The mutant strains of Aspergillus aculeatus have great potential for their further application in the conversion of lignocellulosic biomass into biofuels.

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Improvement of Enzymatic Saccharification of Cellulose-Containing Raw Materials Using Aspergillus niger

Processes ◽

10.3390/pr9081360 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1360

Author(s):

Ekaterina Budenkova ◽

Stanislav Sukhikh ◽

Svetlana Ivanova ◽

Olga Babich ◽

Vyacheslav Dolganyuk ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Aspergillus Niger ◽

Filter Paper ◽

Raw Materials ◽

Enzymatic Saccharification ◽

Wood Chip ◽

Cellulase Activity ◽

Wood Chips ◽

Acid Pretreatment ◽

Hydrolysis Of

Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial enzymes (8.6 versus 9.1 IU), in some cases. Under stationary hydrolysis at 37 °C, pH = 4.7, the enzymatic activity of A. niger UV120 + CH30 was 24.9 IU. The enzymatic hydrolysis of secondary raw materials, using treated A. niger strains, was themost effective at 37 °C. Similarly, the most effective treatment of miscanthus cellulose and wood chips occurred at 50 °C. The maximum conversion of cellulose to glucose was observed using miscanthus cellulose (with alkaline pretreatment), and the minimum conversion was observed when using wood chips. The greatest value of cellulase activity was evidenced in the starch-containing raw materials, indicating that A. niger can ferment not only through cellulase activity, but also via an amylolytic one.

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Synthesis, antibiotic structure–activity relationships, and cellulose dissolution studies of new room-temperature ionic liquids derived from lignin

Biotechnology for Biofuels ◽

10.1186/s13068-021-01898-x ◽

2021 ◽

Vol 14 (1) ◽

Cited By ~ 1

Author(s):

Shihong Liu ◽

Michael Gonzalez ◽

Celine Kong ◽

Scott Weir ◽

Aaron M. Socha

Keyword(s):

Antibacterial Activity ◽

Ionic Liquids ◽

Room Temperature ◽

Oxidation Products ◽

Cellulose Dissolution ◽

Melting Points ◽

E Coli ◽

Alkyl Chains ◽

Renewable Feedstocks ◽

Commodity Chemicals

Abstract Background Ionic liquids (ILs) are promising pretreatment solvents for lignocellulosic biomass, but are largely prepared from petroleum precursors. Benzaldehydes from depolymerized lignin, such as vanillin, syringaldehyde, and 4-methoxy benzaldehyde, represent renewable feedstocks for the synthesis of ionic liquids. We herein report syntheses of novel lignin-derived ionic liquids, with extended N-alkyl chains, and examine their melting points, cellulose dissolution capacities, and toxicity profiles against Daphnia magna and E. coli strain 1A1. The latter organism has been engineered to produce isoprenol, a drop-in biofuel and precursor for commodity chemicals. Results The new N,N-diethyl and N,N-dipropyl methyl benzylammonium ILs were liquids at room temperature, showing 75–100 °C decreased melting points as compared to their N,N,N-trimethyl benzylammonium analog. Extension of N-alkyl chains also increased antibacterial activity threefold, while ionic liquids prepared from vanillin showed 2- to 4-fold lower toxicity as compared to those prepared from syringaldehyde and 4-methoxybenzaldehyde. The trend of antibacterial activity for anions of lignin-derived ILs was found to be methanesulfonate < acetate < hydroxide. Microcrystalline cellulose dissolution, from 2 to 4 wt% after 20 min at 100 °C, was observed in all new ILs using light microscopy and IR spectroscopy. Conclusions Ionic liquids prepared from H-, S- and G-lignin oxidation products provided differential cytotoxic activity against E. coli and D. magna, suggesting these compounds could be tailored for application specificity within a biorefinery.

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Machine learning approaches to understand and predict rate constants for organic processes in mixtures containing ionic liquids

Physical Chemistry Chemical Physics ◽

10.1039/d0cp04227g ◽

2021 ◽

Vol 23 (4) ◽

pp. 2742-2752

Author(s):

Tamar L. Greaves ◽

Karin S. Schaffarczyk McHale ◽

Raphael F. Burkart-Radke ◽

Jason B. Harper ◽

Tu C. Le

Keyword(s):

Machine Learning ◽

Ionic Liquids ◽

Rate Constants ◽

Learning Approaches ◽

Learning Models ◽

Organic Reaction ◽

Machine Learning Models ◽

Selection Of

Machine learning models were developed for an organic reaction in ionic liquids and validated on a selection of ionic liquids.

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Measurement of the hydrogen bond acceptance of ionic liquids and green solvents by the 19F solvatomagnetic comparison method

Green Chemistry ◽

10.1039/d0gc04104a ◽

2021 ◽

Author(s):

Christian Laurence ◽

Sergui Mansour ◽

Daniela Vuluga ◽

Julien Legros

Keyword(s):

Hydrogen Bond ◽

Ionic Liquids ◽

Comparison Method ◽

Green Solvents ◽

Reliable Measurement

A 19F solvatomagnetic comparison of 4-fluorophenol and 4-fluoroanisole yields a more reliable measurement of the hydrogen-bond acceptance of ionic liquids and green solvents than the solvatochromic comparison method.

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Efficient Pretreatment of Wheat Straw Using Novel Renewable Cholinium Ionic Liquids To Improve Enzymatic Saccharification

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.5b03729 ◽

2016 ◽

Vol 55 (6) ◽

pp. 1788-1795 ◽

Cited By ~ 33

Author(s):

Huan Ren ◽

Min-Hua Zong ◽

Hong Wu ◽

Ning Li

Keyword(s):

Ionic Liquids ◽

Wheat Straw ◽

Enzymatic Saccharification

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Intermolecular Hydrogen Bond Plays a Determining Role in Product Selection of Surface Confined Schiff-base Reaction

Chemical Communications ◽

10.1039/d1cc01801a ◽

2021 ◽

Author(s):

Huamei Chen ◽

Guangyuan Feng ◽

Qiu Liang ◽

Enbing Zhang ◽

Yongtao Shen ◽

...

Keyword(s):

Hydrogen Bond ◽

Schiff Base ◽

Hydrogen Bonds ◽

Relative Abundance ◽

Intermolecular Hydrogen Bond ◽

Intermolecular Hydrogen Bonds ◽

Product Selection ◽

Selection Of

Herein, we illustrate how the cooperation of intermolecular hydrogen bonds and conformation flexibility leads to the formation of diverse complex covalent nanostructures on the surface, while the relative abundance of...

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Deep Eutectic Solvents- a New Additive in the Encapsulation of Lipase B from Candida antarctica: Biocatalytic Applications

Reaction Chemistry & Engineering ◽

10.1039/d1re00469g ◽

2022 ◽

Author(s):

Adrian-Ioan Ioan Dudu ◽

Laszlo Csaba Bencze ◽

Csaba Paizs ◽

Monica Ioana Tosa

Keyword(s):

Enzyme Activity ◽

Ionic Liquids ◽

Sol Gel ◽

Deep Eutectic Solvents ◽

Candida Antarctica ◽

Lipase B ◽

Hydroxy Compounds

The enzymes encapsulation in sol-gel matrix can be improved using some additive acting on enzyme activity and/or stability. Ionic liquids, poly-hydroxy compounds, sugars, etc. have been previously reported as additives....

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