Aqueous-organic Solvent Systems Research Articles

Zinc Chemistries of Hybrid Electrolytes in Zinc Metal Batteries: From Solvent Structure to Interfaces.

Along with the booming research on zinc metal batteries (ZMBs) in recent years, operational issues originated from inferior interfacial reversibility have become inevitable. Presently, single-component electrolytes represented by aqueous solution, "water-in-salt," solid, eutectic, ionic liquids, hydrogel, or organic solvent system are hard to undertake independently the task of guiding the practical application of ZMBs due to their specific limitations. The hybrid electrolytes modulate microscopic interaction mode between Zn2+ and other ions/molecules, integrating vantage of respective electrolyte systems. They even demonstrate original Zn2+ mobility pattern or interfacial chemistries mechanism distinct from single-component electrolytes, providing considerable opportunities for solving electromigration and interfacial problems in ZMBs. Therefore, it is urgent to comprehensively summarize the zinc chemistries principles, characteristics, and applications of various hybrid electrolytes employed in ZMBs. This review begins with elucidating the chemical bonding mode of Zn2+ and interfacial physicochemical theory, and then systematically elaborates the microscopic solvent structure, Zn2+ migration forms, physicochemical properties, and the zinc chemistries mechanisms at the anode/cathode interfaces in each type of hybrid electrolytes. Among of which, the scotoma and amelioration strategies for the current hybrid electrolytes are actively exposited, expecting to provide referenceable insights for further progress of future high-quality ZMBs.

Exploring solubility and energetics: Dissolution of biologically important l-threonine in diverse aqueous organic mixtures across the temperature range of 288.15 K to 308.15 K

This research provides a thorough investigation into the solubility behavior and solution thermodynamics of l-threonine in significant organic solvent systems. The work was done on measuring the actual solubility and subsequently calculating overall transfer solvation free energetics (∆Genergetic0i) and transfer entropies (∆St0i) at a temperature of 298.15 K. These measurements were performed as l-threonine transitioned from water to different water-organic mixed solvents systems. The saturated solubilities of l-threonine were determined using the ‘gravimetric method’ at five equidistant temperatures namely 288.15 K, 293.15 K, 298.15 K, 303.15 K and 308.15 K. By analyzing the data on solubility, we further obtained the different energies involved in solvation related issues. In the case of single solvents, the nature of solubility of l-threonine was observed like: dimethylsulfoxide (DMSO) < acetonitrile (ACN) < N, N-dimethylformamide (DMF) < ethylene glycol (EG) < water (H2O), irrespective of the experimental conditions. Specifically, at 298.15 K, the solubilities of l-threonine in single solvents were found to be as follows: 0.8220 mol per kg of water, 0.3101 mol per kg of EG, 0.1337 mol per kg of DMF, 0.1107 mol per kg DMSO and 0.1188 mol per kg of ACN. This research critically examines the relationship between the experimental saturated solubility of l-threonine and the complex properties influencing its solvation energy in diverse aqueous organic solvent systems.

Exploring the solubility and solvation energetics of L-phenylalanine across diverse aqueous organic solutions at five equidistant temperatures (288.15 K to 308.15 K)

This research elucidates comprehensive insights into the dissolution nature and solvation energetics of L-phenylalanine across distinct solvent environments. Specifically, the investigation encompasses saturated solubility measurements and the subsequent derivation of overall transfer free energies (ΔGt0(i)) and entropies (ΔSt0(i)) at 298.15 K, of L-phenylalanine from an aqueous medium to aqueous solutions comprising protic ethylene glycol (EG), dipolar aprotic N,N-dimethylformamide (DMF), acetonitrile (ACN), and dimethyl sulfoxide (DMSO). In this study the 'gravimetric method' was used to find the saturated solubilities of L-phenylalanine at five equidistant temperatures (288.15 K to 308.15 K). These experimental solubility measurements serve as the foundational dataset for the subsequent determination of transfer energies. The investigated drenched or equilibrium solubility data was applied to ascertain the solvation energies. In case of pure solvent, we get the solubility trend of L-phenylalanine as follows: ACN < DMSO < DMF < EG < water, at any temperature. At 298.15 K, we found the solubilities of L- phenylalanine in pure solvents like water, EG, DMF, DMSO and ACN are 0.1675, 0.0911, 0.0888, 0.0850 and 0.0811 mol·kg−1 respectively. A pivotal facet of this study involves the examination of the correlation between the saturated solubility of L-phenylalanine and the intricate characteristics of its solvation energetics across diverse aqueous organic solvent systems.

Redox-Switchable Chalcogen Bonding for Anion Recognition and Sensing.

Inspired by the success of its related sigma-hole congener halogen bonding (XB), chalcogen bonding (ChB) is emerging as a powerful noncovalent interaction with a plethora of applications in supramolecular chemistry and beyond. Despite its increasing importance, the judicious modulation of ChB donor strength remains a formidable challenge. Herein, we present, for the first time, the reversible and large-scale modulation of ChB potency by electrochemical redox control. This is exemplified by both the switching-ON of anion recognition via ChB oxidative activation of a novel bis(ferrocenyltellurotriazole) anion host and switching-OFF reductive ChB deactivation of anion binding potency with a telluroviologen receptor. The direct linking of the redox-active center and ChB receptor donor sites enables strong coupling, which is reflected by up to a remarkable 3 orders of magnitude modulation of anion binding strength. This is demonstrated through large voltammetric perturbations of the respective receptor ferrocene and viologen redox couples, enabling, for the first time, ChB-mediated electrochemical anion sensing. The sensors not only display significant anion-binding-induced electrochemical responses in competitive aqueous-organic solvent systems but can compete with, or even outperform similar, highly potent XB and HB sensors. These observations serve to highlight a unique (redox) tunability of ChB and pave the way for further exploration of the reversible (redox) modulation of ChB in a wide range of applications, including anion sensors as well as molecular switches and machines.

The first tryptophan based turn-off chemosensor for Fe2+ ion detection

In this research work, we have designed and synthesized a novel Tryptophan-Quinoline conjugated turn-off chemosensor 4 for the selective detection of Fe2+ ion with high sensitivity (3.06 μM) among 21 metal cations such as Ag+, Ca+, Cs+, Cu+, K+, Na+, NH4+, Ba2+, Ca2+, Cd2+, Co2+, Cu2+, Mn2+, Ni2+, Pb2+, Zn2+, Al3+, Au3+, Cr3+ and Fe3+ in DMF-HEPES (1 mM, pH = 7.0, 1:1, v/v) aqueous-organic solvent system. It showed a fluorescence quenching mechanism through the blocked PET process. The optical properties, binding mode of the metal ion with the receptor, plausible electron transfer mechanism, and its practical applications have been discussed. This work will open up a new avenue in amino acid-based Fe2+ ion sensors.

Exploration on Hydroxymethylation of Furfural to 5-Hydroxymethylfurfural Over Mesoporous Niobium Phosphate Catalyst

5-Hydroxymethylfurfural (HMF) is mainly produced by dehydration of hexasaccharides which were limited by the source availability and low yield of the process. Accounting to this, the current study was thus designed to first identify the mesoporous niobium phosphate was a tailored catalyst and further to develop a suitable reaction system for hydroxymethylation of furfural to HMF. The mesoporous niobium phosphate was prepared by a two-step sol–gel hydrothermal method used to catalyze this hydroxymethylation reaction either in a pure water solvent or in an aqueous organic solvent system. Detailed investigation on reaction activity and HMF selectivity was carried out by varying reaction conditions. A highest HMF yield of 51.1% was obtained with a 79.2% furfural conversion under the aqueous dimethyl sulfoxide (DMSO) at 90 °C for 20 h over the current catalyst. Moreover, the mesoporous niobium phosphate could be recovered and reused at least for 6 runs without obvious loss in catalytic activity. Mesoporous niobium phosphate was synthesized by a two-step sol–gel hydrothermal method and firstly investigated for the catalytic hydroxymethylation of furfural to HMF. The results suggest that mesoporous niobium phosphate shows a superior activity and selectivity. The highest yield of 51.1% of HMF was obtained with a 79.2% furfural conversion. The excellent catalytic performance could be attributed to attributed to the strong acid sites and larger porous structure in the catalyst.

Correlating the phase settling behavior of aqueous-organic solvent systems in a centrifugal partition chromatograph

The prediction of the performance of a Centrifugal Partition Chromatography (CPC) is a difficult but desirable task. The partitioning of the sample, as well as the fluid dynamical phenomena dispersion, coalescence, and stationary phase retention have to be individually understood. Therefore, the phase settling behavior of different aqueous-organic solvent systems and with this, the dependency of the stationary phase retention in CPC was investigated in this study. On the one hand, batch settling experiments were performed, and the settling velocity of aqueous-organic solvent systems was investigated. With this it was possible to correlate the stationary phase retention in CPC in both operating modes. For descending mode operation a high settling velocity of the lower phase and for ascending mode a high settling velocity of the upper phase is needed for a stable operation and a high stationary phase retention.On the other hand, the dimensionless numbers Capillary number (Ca) and Morton number (Mo) were used to generate a universally applicable correlation for the stationary phase retention in ascending mode. It was shown, that a high stationary phase retention correlates with low values of Ca and Mo, whereas the influence of Mo is neglectable in the parameter space investigated. Within this correlation, the individual influence of each influencing parameter on the stationary phase retention was included. Moreover, this correlation was compared to descriptions for descending mode given in literature. With this it was shown that the minimal stationary phase retention is correlatable to the point of phase inversion.

Characterization and correlation of mobile phase dispersion of aqueous-organic solvent systems in centrifugal partition chromatography

To reach a high separation efficiency using Centrifugal Partition Chromatography (CPC), the fluid dynamical behavior of the liquid-liquid two-phase systems must be clearly understood. The fluid dynamics, namely the dispersion, the coalescence, and the stationary phase retention, have a high impact on a separation. Especially the mobile phase dispersion influences the mass transfer during a separation. In this study, the mobile phase dispersion of different aqueous-organic solvent systems was characterized for ascending and descending mode via video analysis. Thereby the influence of the physical properties of the solvent systems, the operating parameters, and the geometry of the chamber inlet was investigated systematically using dimensional analysis. With the help of the dimensionless numbers Ohnesorge number (OhCPC), Eötvös number (EoCPC), and Weber number (WeCPC) the impact of the solvent system, the plant parameters, and the operating parameters on the mobile phase dispersion could be described. Inside the three dimensional area, spanned by the dimensionless numbers, each state of mobile phase dispersion (undispersed, low dispersed, highly dispersed, and atomized) could be allocated to an individual region for both operating modes. Moreover, differences in mobile phase deflection depending on the operating mode and a possible reason for these were described.

Correlating physical properties of aqueous-organic solvent systems and stationary phase retention in a centrifugal partition chromatograph in descending mode

The performance of the Centrifugal Partition Chromatography (CPC) as a liquid-liquid chromatographic technique depends strongly on the two-phase solvent system used. Thereby the individual influence of the retention of the stationary phase, the coalescence, and the dispersion of the mobile phase in the chambers must be understood to select appropriate solvent systems and reach high separation efficiencies. In this study, an optical measurement system was used to investigate the influence of the physical properties of the Arizona solvent systems on the stationary phase retention in descending mode. Therefore, physical properties like density, viscosity, and interfacial tension were measured as well as the stationary phase retention. Using dimensionless numbers, a correlation between the stationary phase retention and the influencing parameters could be determined. The correlation was validated using data from the literature. Additionally, the solvent systems were modified by additives to identify the validity of the correlation. It was proven that the dimensionless numbers Capillary number (Ca) and Morton number (Mo) can be used to predict the stationary phase retention of other liquid-liquid solvent systems as well as for different operating conditions.

Efficient synthesis of an antiviral drug intermediate using an enhanced short-chain dehydrogenase in an aqueous-organic solvent system.

(2R,3S)-N-tert-Butoxycarbonyl-3-amino-1-chloro-2-hydroxy-4-phenylbutane (1b) is key for the synthesis of the antiviral drug atazanavir. It can be obtained via the stereoselective bioreduction of (3S)-3-(N-Boc-amino)-1-chloro-4-phenyl-butanone (1a) with short-chain dehydrogenase/reductase (SDR). However, the stereoselective bioreduction of this hydrophobic and bulky substrate still remained a challenge because of the steric hindrance effect and low mass transfer rate. In this study, SDR isolated from Novosphingobium aromaticivorans (NaSDR) having low activity to 1a, which was engineered to enhance catalytic efficiency through active pocket iterative saturation mutagenesis (ISM). The obtained mutant (muSDR) (G141V/I195L) had 3.57 times higher kcat than the wild type (WT) towards 1a. Molecular docking analysis revealed considerable differences in the distance between the substrate and catalytic residues in WT and mutant SDR. Moreover, muSDR reduced 15 ketones with excellent enantioselectivity, indicating broad substrate acceptance. After optimization of expression and reaction conditions, the conversion was completed in a scale-up reaction (500mL) using 50% toluene with 500mM substrate without additional NADH. These results show that muSDR may be a valuable biocatalyst for future industrial applications.

A simple oxindole-based colorimetric HSO4¯ sensor: Naked-eye detection and spectroscopic analysis

Detection of hydrogen sulfate from an aqueous organic solvent systems medium attracts to lots of interest because of could be in most environmental and biological systems. In this study, the simple receptors 5 and 6 containing oxindole core were synthesized, and the anion sensing properties were studied using colorimetric, fluorometric detection and 1H-NMR spectroscopy. The research indicated that the specific ligand affinity for hydrogen sulfate ions results in drastic color and spectral changes. According to the data obtained, a new peak at 371 nm in the absorption spectrum of 5 and an increase in fluorescence intensity of 5 were observed in the presence of HSO4¯ ions. The binding ratio of 5 to HSO4¯ was calculated to be 1:1 according to Job's plot experiments. The Ks value was found to be 1.21×105 M−1 using the Benesi-Hildebrand equation. The LOD value was calculated with value as low as 8.9 μM for HSO4¯. Moreover, DFT calculations confirmed the nonplanar structures or propeller structures. As a result of all these studies, it can be said that 5 which is non-toxic, may be a useful and selective candidate turn-on sensor for HSO4¯ sensing in the industrial wastewaters.

Effects of limonene, n-decane and n-decanol on growth and membrane fatty acid composition of the microalga Botryococcus braunii

Botryococcus braunii is a promising microalga for the production of biofuels and other chemicals because of its high content of internal lipids and external hydrocarbons. However, due to the very thick cell wall of B. braunii, traditional chemical/physical downstream processing very often is not as effective as expected and requires high amounts of energy. In this cases, the application of two-phase aqueous-organic solvent systems could be an alternative to cultivate microalgae allowing for a simultaneous extraction of the valuable compounds without significant negative effects on cell growth. Two-phase systems have been applied before, however, there are no studies so far on the mechanisms used by microalgae to survive in contact with solvents present as a second-phase. In this study, the effects of the solvents limonene, n-decane and n-decanol on growth of the microalga B. braunii as well as the adaptive cell response in terms of their phospholipid fatty acid contents were analized. A concentration-dependent negative effect of all three solvents on cell growth was observed. Effects were accompanied by changes of the membrane fatty acid composition of the alga as manifested by a decrease of the unsaturation . In addition, an association was found between the solvent hydrophobicity (given as log octanol–water partition coefficient (text {P}_{O-W}) values) and their toxic effects, whereby n-decanol and n-decane emerged as the most and least toxic solvent respectively. Among the tested solvents, the latter promises to be the most suitable for a two-phase extraction system.

Characterization of a prodigiosin synthetase PigC from Serratia marcescens jx-1 and its application in prodigiosin analogue synthesis

Due to their diverse bioactive effects, prodigiosin and its analogues (prodiginines) have attracted a great deal of attention. In this study, a prodigiosin synthetase PigC catalyzing a condensation reaction to produce prodigiosin was cloned from Serratia marcescens jx-1 and overexpressed in Escherichia coli with a putative polypeptide of 888 amino acids. Its biochemical properties and applications in prodiginines synthesis were investigated. The purified enzyme had a specific activity of 6.96 U/mg and exhibited optimal activity at 10 °C and pH 7.5. The recombinant PigC performed good stability below 30 °C and at pH ranging from 6.0 to 8.5. This enzyme was activated by Ca2+, while inhibited by Cu2+. The kinetic analysis with 4-methoxy-2,2′-bipyrrole-5-carboxyaldehyde (MBC) and 2,4-dimethyl-3-ethylpyrrole (DMEP) as substrates yielded apparent Km of 23.4 and 4.2 μmol/L, respectively. The enzymatic catalysis using whole cells of recombinant E. coli harboring the PigC as catalyst in an aqueous organic solvent system resulted in 59.4% yield of prodigiosin analogues, which exhibited excellent antimicrobial properties against Staphylococcus aureus, Bacillus subtilis and E. coli. The results obtain here demonstrated the great potential of PigC for the biosynthesis of prodigiosin and its analogues.

High-Resolution Capillary Zone Electrophoresis with Mass Spectrometry Peptide Mapping of Therapeutic Proteins: Peptide Recovery and Post-translational Modification Analysis in Monoclonal Antibodies and Antibody-Drug Conjugates.

Reversed phase liquid chromatography with mass spectrometry (RPLC-MS) peptide mapping is routinely used for interrogating molecular and structural attributes such as amino acid composition, sequence variants, and post-translational modifications (PTMs) in antibody-derived therapeutics. RPLC has some limitations that often impact the analysis of certain peptides including large hydrophobic peptides, hydrophilic di-/tripeptides and glycopeptides. Capillary zone electrophoresis with mass spectrometry (CZE-MS) has great potential for peptide mapping due to high efficiency and outstanding sensitivity. In this report we demonstrate the utility of CZE-MS as an orthogonal and complementary technique to RPLC-MS for peptide mapping analyses of antibody-drug conjugates (ADCs) and their parent antibodies. This work is based on high-resolution CZE-MS separation recently developed in our group, where a mixed aqueous-organic solvent system containing N,N-dimethylacetamide (DMA) or N,N-dimethylformamide (DMF) was used to improve the separation selectivity. The results described here show several advantages of CZE-MS for the analysis of small hydrophilic di-/tripeptides, large hydrophobic peptides, glycopeptides, and hydrophobic drug-linked peptides.

Inverse thermoresponse of a water-soluble helicene oligomer in aqueous-organic mixed solvent systems

A water-soluble ethynylhelicene (M)-tetramer with TEG groups exhibited the inverse thermoresponse in water/triethylamine/acetone, in which heating induced the formation of double helix and cooling dissociation. In this study, we examined the solvent effect with regard to water content at temperatures between 5 and 40 °C, and showed that the inverse thermoresponse occurred in different aqueous solution systems. In acetone, the oligomer exhibited the ordinary thermoresponse: Cooling induced the formation of double helix and heating dissociation. The increase in water content to approximately 10% caused the switch to the inverse thermoresponse. Further increase inhibited the association, and did not induce the thermoresponse. When the water content was increased to approximately 50%, the inverse thermoresponse appeared as observed previously study. Two types of inverse thermoresponses, termed type I and II, appeared at high and low water contents, respectively.

Enzymatic synthesis of an ezetimibe intermediate using carbonyl reductase coupled with glucose dehydrogenase in an aqueous-organic solvent system

(4S)-3-[(5S)-5-(4-Fluorophenyl)-5-hydroxypentanoyl]-4-phenyl-1,3-oxazolidin-2-one ((S)-ET-5) is an important chiral intermediate in the synthesis of chiral side chain of ezetimibe. Recombinant Escherichia coli expressing carbonyl reductase (CBR) was successfully constructed in this study. The total E. coli biomass and the specific activity of recombinant CBR in 5L fermenter culture were 10.9gDCWL−1 and 14900.3Ug−1DCW, respectively. The dual-enzyme coupled biocatalytic process in an aqueous-organic biphasic solvent system was first constructed using p-xylene as the optimal organic phase under optimized reaction conditions, and 150gL−1 (4S)-3-[5-(4-fluorophenyl)-1,5-dioxophentyl]-4-phenyl-1,3-oxazolidin-2-one (ET-4) was successfully converted to (S)-ET-5 with a conversion of 99.1% and diastereomeric excess of 99% after 24-h, which are the highest values reported to date for the production of (S)-ET-5.

Liquid-liquid interface assisted synthesis of SnO2 nanorods with tunable length for enhanced performance in dye-sensitized solar cells

Single-crystalline SnO2 nanorods with tunable length are synthesized via a facile and surfactant-free solvothermal route based on an aqueous–organic solvent system. The length of the nanorods can be facilely controlled by adjusting the solvent ratio. Particularly, the average length increases from 14.6 to 98.0nm when the volume ratio of cyclohexane to water is varied from 20:30 to 49:1. The morphological evolution of the SnO2 nanorods is systematically investigated, and a growth mechanism involving three stages of nucleation, rearrangement and oriented growth is proposed, based on the free migration of the nanoparticles at the two immiscible interfaces thereby offering special path for the self-assembly. The synthesized SnO2 nanorods are used as photoanodes for dye-sensitized solar cells (DSSCs) and the photovoltaic performance is studied as a function of the morphology. UV–vis absorption spectra show the dye-loading capabilities of the DSSCs are gradually weaken with the length increase of the SnO2 nanorods. Electrochemical impedance spectroscopy analysis indicates that the charge transfer resistances at the SnO2/dye/electrolyte interfaces decrease and the electron lifetimes increase along with the increase of nanorod-length. As a consequence, DSSCs fabricated from medium-sized nanorods achieve the best power conversion efficiency of 3.50% due to the equilibrium between fast electron transport and large specific surface area.

A direct method for the N-tetraalkylation of azamacrocycles.

An efficient protocol for the direct synthesis of N-tetraalkylated derivatives of the azamacrocycles cyclam and cyclen has been developed, using a partially miscible aqueous–organic solvent system with propargyl bromide, benzyl bromide, and related halides. The method works most effectively when the reaction mixture is shaken, not stirred. A crystal structure of the N-tetrapropargyl cyclam derivative 1,4,8,11-tetra(prop-2-yn-1-yl)-1,4,8,11-tetraazacyclotetradecane diperchlorate is reported.

Enhancement of Palmarumycin C12 and C13 Production by the Endophytic Fungus Berkleasmium sp. Dzf12 in an Aqueous-Organic Solvent System.

The endophytic fungus Berkleasmium sp. Dzf12, isolated from Dioscorea zingiberensis, was found to produce palmarumycins C12 and C13 which possess a great variety of biological activities. Seven biocompatible water-immiscible organic solvents including n-dodecane, n-hexadecane, 1-hexadecene, liquid paraffin, dibutyl phthalate, butyl oleate and oleic acid were evaluated to improve palmarumycins C12 and C13 production in suspension culture of Berkleasmium sp. Dzf12. Among the chosen solvents both butyl oleate and liquid paraffin were the most effective to improve palmarumycins C12 and C13 production. The addition of dibutyl phthalate, butyl oleate and oleic acid to the cultures of Berkleasmium sp. Dzf12 significantly enhanced palmarumycin C12 production by adsorbing palmarumycin C12 into the organic phase. When butyl oleate was fed at 5% (v/v) in medium at the beginning of fermentation (day 0), the highest palmarumycin C12 yield (191.6 mg/L) was achieved, about a 34.87-fold increase in comparison with the control (5.3 mg/L). n-Dodecane, 1-hexadecene and liquid paraffin had a great influence on the production of palmarumycin C13. When liquid paraffin was added at 10% (v/v) in medium on day 3 of fermentation, the palmarumycin C13 yield reached a maximum value (134.1 mg/L), which was 4.35-fold that of the control (30.8 mg/L). Application of the aqueous-organic solvent system should be a simple and efficient process strategy for enhancing palmarumycin C12 and C13 production in liquid cultures of the endophytic fungus Berkleasmium sp. Dzf12.

Detergent-Stable Salt-Activated Proteinases from Virgibacillus halodenitrificans SK1-3-7 Isolated from Fish Sauce Fermentation.

The NaCl-activated and detergent-stable proteinases from Virgibacillus halodenitrificans SK1-3-7 isolated from fish sauce fermentation were purified and characterized. The enzymes with molecular masses of 20 and 36 kDa showed caseinolytic activity on a zymogram. Optimum azocaseinolytic activity was at 60 °C and pH 9. The proteolytic activity increased in the presence of 10 mM CaCl2 and 0.5 M NaCl and showed high stability at 0-2 M NaCl. The enzymes were stable at pH 4-10 and 10-50 °C. The enzymes preferably hydrolyzed Suc-Ala-Ala-Pro-Phe-pNA and were completely inhibited by phenylmethanesulfonyl fluoride (PMSF), showing subtilisin-like characteristics. Activity and stability remained high in the presence of H2O2 and various surfactants. The enzymes exhibited high stability (>95%) in various organic solvents (DMSO, butanol, ethanol, 2-propanol, and acetonitrile) at concentration of 50%. The V. halodenitrificans SK1-3-7 proteinases showed potential as a biocatalyst in aqueous-organic solvent systems and as an additive in laundry detergent.