Impact of Ionic Liquid Physical Properties on Lipase Activity and Stability

Kaar, Joel L.; Jesionowski, Anita Mesiano; Berberich, Jason A.; Moulton, Roger; Russell, Alan J.

doi:10.1021/ja028557x

Cited by 542 publications

(374 citation statements)

References 32 publications

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“…For instance, ILs containing alkyl groups between 10 and 14 carbon atoms are considered toxic toward bacteria and fungi. Designing ILs with alkyl groups shorter than 10 carbon atoms may avoid microbial toxicity (Pernak et al 2003 (Kaar et al 2003) . The conclusion from all of these studies is that simple alterations in the chemistry of ILs can greatly reduce toxicity of IL to microorganisms and enzymes used in the downstream conversion steps.…”

Section: Approaches To Manage Il Toxicitymentioning

confidence: 99%

Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts

Simmons

Singer

et al. 2016

Appl Microbiol Biotechnol

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Chemical and physical pretreatment of biomass is a critical step in the conversion of lignocellulose to biofuels and bioproducts. Ionic liquid (IL) pretreatment has attracted significant attention due to the unique ability of certain ILs to solubilize some or all components of the plant cell wall. However, these ILs not only inhibit enzyme activities, but also the growth and productivity of microorganisms used in downstream hydrolysis and fermentation processes.While pretreated biomass can be washed to remove residual IL and reduce inhibition, extensive washing is costly and not feasible in large-scale processes. IL tolerant microorganisms and microbial communities have been discovered from environmental samples and studies begun to elucidate mechanisms of IL tolerance. The discovery of IL tolerance in environmental microbial communities and individual microbes has lead to the proposal of molecular mechanisms of resistance. In this article, we review recent progress on discovering IL tolerant microorganisms, identifying metabolic pathways and mechanisms of tolerance, and engineering microorganisms for IL tolerance. Research in these areas will yield new approaches to overcome inhibition in lignocellulosic biomass bioconversion processes and increase opportunities for the use of ILs in biomass pretreatment.

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Section: Approaches To Manage Il Toxicitymentioning

confidence: 99%

Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts

Simmons

Singer

et al. 2016

Appl Microbiol Biotechnol

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“…It has been suggested that ionic liquids containing the anions Cl -, Br -, NO 3 -, and CF 3 SO 3 -denature enzymes owing to their higher basicity and, hence, higher affinity for hydrogen bonds. 22,40 There are diverse opinions concerning the effect of fluorinated anions, such as BF 4 and PF 6 , on the enzyme's lifetime. Some reports suggest that since charge can be distributed over several fluorine atoms, the hydrogen bond affinity is minimized between the solvent and the enzyme and that, consequently, there is no interference with the internal hydrogen bonding network of the enzyme, maintaining its secondary structure.…”

Section: Introductionmentioning

confidence: 99%

Enzyme-Catalyzed Hydrolysis of Cellulose in Ionic Liquids: A Green Approach Toward the Production of Biofuels

2010

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We investigated the reactivity and stability of a commercial mixture of cellulases in eight ionic liquids by optical and calorimetric techniques. First, hydrolysis by cellulases from Tricoderma reesei in these ionic liquids was benchmarked against that in aqueous buffer. Only 1-methylimidazolium chloride (mim Cl) and tris-(2-hydroxyethyl)methylammonium methylsulfate (HEMA) provided a medium in which hydrolysis could occur. While hydrolysis at 65 °C is initially much faster in buffer than in these two liquids, it reaches a plateau after 2 h, whereas the reaction progresses monotonically in the two ionic liquids. This difference in the rate of hydrolysis is largely attributed to two factors: (1) the higher viscosity of the ionic liquids and (2) the enzymes are irreversibly denatured at 50 °C in buffer while they are stable to temperatures as high as 115 °C in HEMA. We explored whether fluorescence quenching of aromatic amino acids of the enzymes was indeed a signature of protein denaturation, as has been suggested in the literature, and concluded that quenching is not necessarily associated with denaturation. When it does occur, for example, in the presence of ionic liquids formed from imidazolium cations and chloride anions, it arises from the imidazolium rather than the chloride. Finally, we conclude that HEMA is a promising, novel, green medium for performing cellulose hydrolysis reactions to convert biomass into biofuels. Because of the thermal stability it imparts to enzymes, its ability to solubilize biomass, and the fact that it does not quench tryptophyl fluorescence (thus permitting monitoring of the enzymes by fluorescence spectroscopy), HEMA provides an ideal starting point for the design of ionic liquids, not only for the hydrolysis of biomass, but also for use with a wide spectrum of enzymatic reactions. KeywordsAmino acids, biofuels, biomass, catalysts, cellulose, chlorine compounds, denaturation, enzymes, fluorescence, fluorescence spectroscopy, hydrolysis, ionization of liquids, organic acids, aromatic amino acid, calorimetric techniques, chloride anions, commercial mixtures Arlington, P.O. Box 19065, Arlington, Texas 76019 ReceiVed: December 21, 2009; ReVised Manuscript ReceiVed: March 16, 2010 We investigated the reactivity and stability of a commercial mixture of cellulases in eight ionic liquids by optical and calorimetric techniques. First, hydrolysis by cellulases from Tricoderma reesei in these ionic liquids was benchmarked against that in aqueous buffer. Only 1-methylimidazolium chloride (mim Cl) and tris-(2-hydroxyethyl)methylammonium methylsulfate (HEMA) provided a medium in which hydrolysis could occur. While hydrolysis at 65°C is initially much faster in buffer than in these two liquids, it reaches a plateau after 2 h, whereas the reaction progresses monotonically in the two ionic liquids. This difference in the rate of hydrolysis is largely attributed to two factors: (1) the higher viscosity of the ionic liquids and (2) the enzymes are irreversibly denatured at 50°C in b...

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“…(12) tetraflouroborate, (13) hexaflourophosphate, (14) hexafluoro antimonate, (15) nitrate, (16) tosylate, (17) triflate, (18) bromide, (19) chloride, (20) iodide, (21) triflouroacetate (22) perchlorate (23) germanium chloride, (24) bis(trifluoromethylsulfonyl) imide, (25) aluminium chloride, (26) aluminium tetrachloride, (27) acetate, (28) benzoate reactions can often be recovered from RTILs by means of extraction. Supercritical CO 2 , water or organic solvents can be used to recover products and enable the recycling of RTIL for subsequent reactions.…”

Section: Fig (3)mentioning

confidence: 99%

Ionic Liquids in Carbohydrate Chemistry—Current Trends and Future Directions

Murugesan

Linhardt

2006

ChemInform

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Room Temperature Ionic Liquids (RTILs) have recently been introduced as new solvents in the chemical and biotechnological arenas. Carbohydrates are important natural products that play important biological and commercial roles as foods, drugs and chemical feedstocks. They have two properties that complicate their use a low solubility in most solvents and complex, highly chiral structures. We are currently witnessing a rapid increase in novel applications for newly discovered RTILs. This account reviews the application of RTILs in carbohydrate chemistry and biochemistry as a mono / biphasic solvent, a solvent / catalyst and a product retrieval media.

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Impact of Ionic Liquid Physical Properties on Lipase Activity and Stability

Cited by 542 publications

References 32 publications

Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts

Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts

Enzyme-Catalyzed Hydrolysis of Cellulose in Ionic Liquids: A Green Approach Toward the Production of Biofuels

Ionic Liquids in Carbohydrate Chemistry—Current Trends and Future Directions

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