Search

In the present work, the toxic effect of various solvents with different Log P values was studied on the whole cells of Candida viswanathii. Experiments showed that the lower concentrations of some solvent increased both the activity retention and enzyme activity as compared to the control while this was not the case with higher concentrations of the same solvents. The model compound taken in the present study was 1-acetophenone. The percentage conversion improved from 76 to 94%. Addition of 2-propanol increased the substrate tolerance, giving the conversion of 90% compared to 9% in control at a substrate concentration of 70mM in 1h. The operational stability increased at higher temperatures with the addition of 2-propanol in the reaction mixture with good conversion (90%) and enantiomeric excess (>99%) at 45°C and 50°C. The effect was also found to be prominent in other tested substrates. In order to further stabilize the cells for long term use in higher concentration of organic solvents, the cells were further immobilized, and were found to have higher activity retention than that of free cells. [Copyright &y& Elsevier]

Abstract: Many kinds of biomass are being tested as a biosorption material for metal removal from the contaminated waters. In the present study the biosorption capacity of an organic solvent tolerant (OST) bacterium was investigated against Cr(VI) and Ni(II). The OST strain of Pseudomonas fluorescens TEM08 was isolated from an oil contaminated soil sample and grown in normal culture conditions (type I) and in the presence of the cyclohexane (type II). Two types of cells were used in the biosorption experiments to compare the organic solvent effect on the biosorption capacity. The biosorption equilibrium was described by Langmuir and Freundlich adsorption isotherms. The value of Q0 was higher for type I cells (40.8 for Cr(VI); 12.4 for Ni(II)) then the type II (40.7 for Cr(VI); 11.2 for Ni(II)). The adsorption capacity constants (K F) of Freundlich model for type I cells and for type II cells were 10.87 and 8.78 for Ni(II) and 13.60 and 10.99 for Cr(VI), respectively. [Copyright &y& Elsevier]

[Display omitted] • First ever an integrated amphidinol-prioritized fractioning approach. • The approach readily separates specialty metabolites of the alga Amphidinium carterae. • Compared to a solvent partitioning method, the integrated approach was more efficient. • NMR-based metabolomics is a valuable tool for screening solvent extraction methods. An amphidinol-prioritized fractioning approach was for the first time developed to isolate multiple specialty metabolites such as amphidinols, carotenoids and fatty acids using the biomass of the marine microalgae Amphidinium carterae. The biomass was produced in a raceway photobioreactor and the exhausted culture media were reused, thus fulfilling sustainability criteria employing a circular economy concept. The integrated bioactive compounds-targeted approach presented here consisted of four steps with which recovery percentages of carotenoids, fatty acids and amphidinols of 97%, 82% and 99 %, respectively, were achieved. The proposed process was proved to be a better extraction system for this microalga than another based on a sequential gradient partition with water and four water-immiscible organic solvents (hexane, carbon tetrachloride, dichloromethane and n -butanol). The proposed process could be scaled-up as a commercial solid-phase extraction technology well-established for industrial bioprocesses. [ABSTRACT FROM AUTHOR]

[Display omitted] • OxiOrganosolv with isobutanol as solvent was used for beechwood pretreatment. • High delignification rates, up to 97%, were achieved. • Around 50 wt% of initial hemicellulose was recovered as XOS in the liquid fraction. • Enzymatic hydrolysate supported C. cohnii growth and lipid accumulation (~52 wt%) • Up to 51.6 g /L (0.57 g/g biomass) D-lactic acid was produced through SSF. The aim of this work was to investigate the use of isobutanol as organic solvent for the efficient delignification and fractionation of beechwood through the OxiOrganosolv process in the absence of any catalyst. The results demonstrate that cellulose-rich solid pulp produced after pretreatment is a source of fermentable sugars that can be easily hydrolyzed and serve as a carbon source in microbial fermentations for the production of omega-3 fatty acids and D-lactic acid. The C5 sugars are recovered in the aqueous liquid fractions and comprise a fraction rich in xylo -oligosaccharides with prebiotic potential. The maximum production of optically pure D-lactic from Lactobacillus delbrueckii sp. bulgaricus reached 51.6 g/L (0.57 g/g biomass), following a simultaneous saccharification and fermentation strategy. Crypthecodenium cohnii accumulated up to 52.1 wt% lipids with a DHA content of 54.1 %, while up to 43.3 % hemicellulose recovery in form of oligosaccharides was achieved in the liquid fraction. [ABSTRACT FROM AUTHOR]

Forty-three strains were screened from crude oil-contaminated samples by toluene and cyclohexane enrichment in medium. Ten of these strains demonstrated high protease activity on skim-milk agar. Among them, the PT121 isolate, identified as Pseudomonas aeruginosa, was selected based on its extracellular protease stability in the presence of hydrophilic organic solvents. The crude protease also retained most of its activity up to at least 14 days in the presence of various organic solvents at 50% concentration, and the protease activity in production medium was 10,876U/ml after 72h incubation. This protease showed high activity as a catalyst for aspartame precursor Cbz-Asp-Phe-NH2 synthesis in the presence of 50% dimethylsulfoxide (DMSO). [Copyright &y& Elsevier]

Abstract: Solvent tolerant Pseudomonas aeruginosa strain PseA has been studied for lipase activity. This strain has earlier been reported to be secreting alkaline and solvent stable protease. It produced an extra cellular lipase with suitable properties for detergent applications viz. (i) alkaline in nature, (ii) stability and compatibility towards bleach oxidants, surfactants and detergent formulations and (iii) resistant to proteolysis. Since the culture supernatant contains both protease and lipase which are together required in detergent formulations, enzymes from P. aeruginosa seem ideal for use as detergent additive. P. aeruginosa lipase exhibited remarkable stability in wide range of organic solvents at 25% (v/v) concentration. This property can be useful for solvent bioremediation and biotransformations in non-aqueous media. Media optimization for cost effective production of lipase was carried out by response surface methodology which led to 5.58-fold increase in lipase production (4580IU/ml) over un-optimized media. [Copyright &y& Elsevier]

Abstract: Malaysian enzyme industry is considered almost non-existence, although the import volume is large. Realizing the importance of enzymes, encompassing a wide range of applications in bioindustry, the development of home grown technologies for enzyme production and applications becomes one of the national priorities in industrial biotechnology. Enzyme production from indigenous microbial isolates was performed either by submerged or solid state fermentation processes. Based on its wide and unique spectrum of properties, enzymes have been developed for wide applications in various industrial processes. The development of the enzyme catalysed applications is based on the modification of the reaction systems to enhance their catalytic activities. Some of the applications of the industrial enzymes include the fine chemicals production, oleochemicals modification, detergent formulation, enzymatic deinking of waste papers, animal feed formulation and effluent treatment processes. Enzymes have also shown to be successfully used as analytical tool in the determination of compounds in body fluids. Although, most of these enzyme catalysed reactions were performed in aqueous phase, the use of enzymes in organic solvents was found to be significant for the production of new chemicals. [Copyright &y& Elsevier]

Abstract: Oil palm empty fruit bunches were used as an alternative raw material to obtain cellulosic pulp. Pulping was done by using high-boiling point organic solvents of decreased polluting power relative to classical (Kraft, sulphite) solvents but affording operation at similar pressure levels. The holocellulose, α-cellulose and lignin contents of oil palm empty fruit bunches (viz. 66.97%, 47.91% and 24.45%, respectively) are similar to those of some woody raw materials such as pine and eucalyptus, and various non-wood materials including olive tree prunings, wheat straw and sunflower stalks. Pulping tests were conducted by using ethyleneglycol, diethyleneglycol, ethanolamine and diethanolamine under two different sets of operating conditions, namely: (a) a 70% solvent concentration, 170°C and 90min; and (b) 80% solvent, 180°C and 150min. The solid/liquid ratio was six in both cases. The amine solvents were found to provide pulp with better properties than did the glycol solvents. Ethanolamine pulp exhibited the best viscosity and drainage index (viz. 636mL/g and 17 °SR, respectively), and paper made from it the best breaking length (1709m), stretch (1.95%), burst index (0.98kN/g) and tear index (0.33mNm2/g). Operating costs can be reduced by using milder conditions, which provide similar results. In any case, the amines are to be preferred to the glycols as solvents for this purpose. [Copyright &y& Elsevier]

Abstract: A solvent tolerant strain of Pseudomonas aeruginosa (PseA) was isolated from soil samples by cyclohexane enrichment in medium. The strain was able to sustain and grow in a wide range of organic solvents. The adaptation of P. aeruginosa cell towards solvents was seen at membrane level in transmission electron micrographs. It also secreted a novel protease, which exhibited remarkable solvent stability and retained most of the activity at least up to 10days in the presence of hydrophobic organic solvents (log P ⩾2.0) at 25% (v/v) concentrations. The protease was able to withstand as high as 75% concentration of solvents atleast up to 48h. P. aeruginosa strain and its protease, both seem promising for solvent bioremediation, wastewater treatment and carrying out biotransformation in non-aqueous medium. [Copyright &y& Elsevier]

The physical factors affecting the production of an organic solvent-tolerant protease from Pseudomonas aeruginosa strain K was investigated. Growth and protease production were detected from 37 to 45 °C with 37 °C being the optimum temperature for P. aeruginosa. Maximum enzyme activity was achieved at static conditions with 4.0% (v/v) inoculum. Shifting the culture from stationary to shaking condition decreased the protease production (6.0–10.0% v/v). Extracellular organic solvent-tolerant protease was detected over a broad pH range from 6.0 to 9.0. However, the highest yield of protease was observed at pH 7.0. Neutral media increased the protease production compared to acidic or alkaline media [Copyright &y& Elsevier]

Poly(lactic acid) is among the most important biodegradable, biocompatible polymers. To explore the feasibility of making poly(lactic acid) through potentially more selective enzymatic methods, the lipase-catalyzed direct polycondensation of lactic acid in organic solvents was investigated. At 37 °C the reaction was found to favor nonpolar solvents with larger logP values and smaller logSw/o values. The addition of silica gel appeared to greatly enhance the lactic acid conversion (up to 98%) and the lipase stability under the reaction condition. However, upon further investigations, the silica gel itself was found to catalyze the polycondensation, in addition to the role of water removal. The conversion catalyzed by silica gel alone was actually higher than that by silica gel+lipase (or lipase alone). Up to 93% conversion of the acid functional group (or about 99.5% conversion of lactic acid monomer) was obtained in 120 h with silica gel as the catalyst. The finding is especially significant for interpreting (or reconsidering) the results of many presumably enzyme-catalyzed organic-phase reactions in the presence of silica gel. [Copyright &y& Elsevier]

[Display omitted] • A novel thermostable/halotolerant PersiLac2 screened from tannery wastewater. • The enzyme was highly active and stable in a wide temperature and pH ranges. • The PersiLac2 decolorized azo, anthraquinone, and triphenylmethane dyes rapidly. • The PersiLac2 is used for detoxification of dyes used in the textile industry. A novel thermostable/halotolerant metagenome-derived laccase (PersiLac2) from tannery wastewater was purified to remove textile dyes in this study. The enzyme was highly active over a wide temperature and pH range and maintained 73.35% of its initial activity after 30 days, at 50 °C. The effect of various metal and organic-solvent tolerance on PersiLac2 showed, retaining greater than 53% activity at 800 mM of metal ions, 52.12% activity at 6 M NaCl, and greater than 44.09% activity at 20% organic solvents. PersiLac2 manifested effective removal of eight different textile dyes from azo, anthraquinone, and triphenylmethane families. It decolorized 500 mg/L of Alizarin yellow, Carmine, Congo red and Bromothymol blue with 99.74–55.85% efficiency after 15 min, at 50 °C, without mediator. This enzyme could practically remove dyes from a real textile effluent and it displayed significant detoxification in rice seed germination tests. In conclusion, PersiLac2 could be useful in future for decolorization/detoxification of wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Engineering of ethanol-interacting sites of lipase A for improving stability. • The Ser16Gly mutant showed 1.8-fold higher stability than wild-type in 50% ethanol. • The Leu108Asn mutant showed 1.5-fold higher thermostability than wild-type at 45 °C. • This strategy can be applicable for constructing organic solvent-resistant enzymes. Given that lipase is an enzyme applicable in various industrial fields and water-miscible organic solvents are important reaction media for developing industrial-scale biocatalysis, a structure-based strategy was explored to stabilize lipase A from Bacillus subtilis in a water–ethanol cosolvent. Site-directed mutagenesis of ethanol-interacting sites resulted in 4 mutants, i.e., Ser16Gly, Ala38Gly, Ala38Thr, and Leu108Asn, which were stable in 50% ethanol and had up to 1.8-fold higher stability than the wild-type. In addition, Leu108Asn was more thermostable at 45 °C than the wild type. The results discussed in this study not only provide insights into strategies for enzyme engineering to improve organic solvent resistance but also suggest perspectives on pioneering routes for constructing enzyme-based biorefineries to produce value-added fuels and chemicals. [ABSTRACT FROM AUTHOR]

• Lignin extracted from sawdust biomass by alkali fractionation method. • Structure, total phenol content and antioxidant characteristics of lignin were analyzed. • Industrial level model was developed for the simulation of lignin fractionation process. • Economic and sensitivity of lignin fractionation process were analyzed. The present work was focused on the investigation of lignin isolation from saw industry biomass (sawdust (SD)) using alkali solution, and to perform economic analysis for 2000 kg/batch hypothetical plant using techno-economic analysis. The isolated lignin was fractionated using organic solvent to obtain purified lignin. FTIR and 1H NMR analysis were performed to examine the structural characteristics of lignin. Lignin nanoparticles (LN) showed higher total phenolic content (TPC) (244.1 ± 2 µg of GAE per mg) and antioxidant activity (63.2 ± 1.7%) compared with crude lignin (CL), ethanol fractionated lignin (EL), and acetone fractionated lignin (AL). SuperPro designer was exposed to design and simulated 2000 kg/batch of sawdust fractionation process. The techno-economic analysis estimated that the lignin production cost is about $ 487,000 per year, and the annual revenue could be $ 1,850,000 per year. The techno-economic analysis and sensitivity analysis could be useful for the industrial level sawdust fractionation process. [ABSTRACT FROM AUTHOR]

• [DPDIm]I based ionic liquid is a potential solvent and catalyst in bioprocessing. • Ionic liquid in bioprocessing requires low temperature and less reaction time. • Ionic Liquid catalyzed 94% of cellulose to levulinic acid (LA). • Ionic liquid was recycled five times for the efficient production of LA. Ionic liquid (IL) demonstrates better performance as a solvent in the biomass conversion process than conventional organic solvents. This study focuses on the application of new hydrophobic imidazolium-based IL as a solvent in biomass conversion process. A novel IL, namely, 1,3-dipropyl-2-(2-propoxyphenyl)-4,5-diphenylimidazolium iodide ([DPDIm]I), was synthesized and subsequently used as a solvent for biomass conversion to produce levulinic acid (LA) and Formic Acid (FA). The performance of [DPDIm]I supported by H 2 SO 4 as a solvent was shown by cellulose conversion into 94.23% of LA and 18.85% of FA at the optimum conditions of 140 °C temperature and the reaction time of two hours. A reusability test revealed the performance of [DPDIm]I as a solvent that can be recycled up to five times for biomass conversion. [ABSTRACT FROM AUTHOR]

Abstract: A functional lignin-based material, lignocresol, was synthesized from eucalyptus wood meal by using phase separation treatment with p-cresol and 72% sulfuric acid. Lignocresol physically adsorbs Trichoderma reesei cellulase and functions as an immobilized cellulase. Lignocresol-immobilized cellulase was treated with acetone or ethanol to separate the enzyme and its support. Most lignocresol was dissolved in organic solvents and then precipitated in diethyl ether. The recovery yield of lignocresol using acetone was 85% and that using ethanol was 72%, with very low or negligible residual cellulase. Lignocresol is an innovative recyclable enzyme support that can be easily separated using only organic solvents after deactivation of the immobilized enzyme. [Copyright &y& Elsevier]

Abstract: Pavlova sp. was employed to evaluate the efficiency of different lipid extraction methods. The microalgal crude lipids content determined using the mixed solvent with ultrasonic method was 44.7wt.%. The triglyceride content obtained by the mixed solvent method was 15.6wt.%. The extraction yield was the FAME yield divided by the maximum FAME (15.9wt.%). The extraction yield was improved by cell disruption prior to extraction, and the highest triglyceride extraction yield of 98.7% was observed using the supercritical fluid extraction (SFE) method with bead-beating. The results indicate that the SFE method is effective and provides higher selectivity for triglyceride extraction though the total lipid extracted was less than that using solvent extraction. [Copyright &y& Elsevier]

Abstract: The effects of important reaction parameters on the enhancement of sialic acid derivative lipophilic properties through the lipase-catalyzed esterification of N-acetyl neuraminic acid methyl ester are investigated in this study. It is found that the lipase Novozym 435 from Candida antarctica is particularly useful in the preparation of sialic acid methyl ester monononanoate (SAMEMN). The optimum temperature for the SAMEMN synthesis reaction using Novozym 435 is 60°C, and nonanoic anhydride is found to be the best substrate among all acyl donors. The Novozym 435-catalyzed esterification of N-acetyl neuraminic acid methyl ester gave a maximum yield of 87.7% after 6h in acetonitrile at 60°C. Because the novel method developed is simple, yet effective, it could potentially be used industrially for the production of sialic acid derivatives. [Copyright &y& Elsevier]

Abstract: In this work, experiments were carried out to evaluate the esterification activity and conformation of lipase from Burkholderia cepacia in the selected conventional organic solvents, ionic liquids and their co-solvent mixture media. The results revealed that the activity of esterification of B. cepacia lipase was mostly highest in co-solvent mixture of ionic liquids–organic solvents, followed by conventional organic solvents and ionic liquids. Hence, co-solvent mixture was a high-effective strategy to enhance the activity of B. cepacia lipase for non-aqueous enzymology reaction. Conformational studies via circular dichroism spectroscopy indicated that the secondary structure of B. cepacia lipase was variant in the above-mentioned media, especially the content of α-helix, which was probably responsible for lipase activity difference. [ABSTRACT FROM AUTHOR]

• Kraft lignin was fractionated by 5 organic solvents. • Higher heating value is inversely proportional to the molar mass. • GPC molar mass distribution increased from fraction 1 (F1) to fraction 5 (F5) • Thermal degradation of lignin in the 300–400 ℃ range was verified. The new concept of integrated biorefineries has significantly changed pulp and paper industries. Lignin, which until then was only burned to generate energy, is now an important raw material for new products production. Kraft lignin (KL) fractions obtained by sequential fractionation with five organic solvents. This sequence allows to extract fractions from lower molar mass to higher molar one, resulting in more homogeneous samples. Lignin's fractions were characterized by FTIR, GPC, TGA and Higher Heating Value (HHV). HHV for KL was 24966, the lowest being 17,891 (F5) and the highest being 27051 J/g (F1), inversely proportional to the molar masses of fractions. This is a very important result indicating that the lower HHV fractions can be used for certain applications, such as antioxidants, additives, polymers, among others, adding value to kraft lignin. Fractions with higher HHV could be used for energy generation in the cellulose paper industry. [ABSTRACT FROM AUTHOR]

• Microwave-assisted Sn-argil converted biomass into furfural in biphasic media. • High distribution coefficient (Kd) in organic solvent could enhance furfural yields. • Furfural was oxidized to furoic acid by immobilized Brevibacterium lutescens cells. • Reuse of Sn-argil and immobilized cells was conducted for synthesis of furoic acid. • Chemoenzymatic strategy was developed for converting SDS to furoic acid. In this study, chemoenzymatic conversion of Sorghum durra stalk (SDS) into furoic acid was developed by a sequential microwave-assisted solid acid conversion and immobilized whole-cells biocatalysis method. Dry dewaxed SDS (75 g/L) was catalyzed into furfural at 57.8% yield with heterogeneous Sn-argil (2.0 wt% dosage) in n-ethyl butyrate-H 2 O (1:1, v:v) biphasic system using a microwave (600 W) for 10 min at 180 °C. In this biphasic media (pH 6.5), SDS-derived furfural (125.0 mM) was biologically oxidized to furoic acid by immobilized Brevibacterium lutescens cells harboring furfural-oxidizing activity at 30 °C, and furfural was wholly transformed to furoic acid within 24 h. Finally, the recovery and reuse of the Sn-argil catalyst and immobilized biocatalysts were conducted for synthesizing furoic acid from SDS in the biphasic system. This chemoenzymatic route can be attractive for furoic acid production. [ABSTRACT FROM AUTHOR]

• Fractionation, product isolation, and solvent recycling require a holistic approach. • A solvent environment akin to the solute's chemical properties enhances solubility. • Miscible aqueous solvents can benefit from fractional anti-solvent properties. • Recycling schemes for miscible aqueous solvents fall into one of two categories. • Liquid-liquid phase separation and successive product isolation ease recycling. Organosolv treatment is among the most promising strategies for valorising lignocellulosic biomass and could facilitate the transition towards enhanced utilization of renewable feedstocks. However, issues such as inefficient solvent recycle and fractionation has to be overcome. The present review aims to address these issues and discuss the role of the components present during organosolv treatment and their influence on the overall process. Thus, the review focuses not only on how the choice of solvent and catalyst affects lignocellulosic fractionation, but also on how the choice of treatment liquor influences the possibility for solvent recycling and product isolation. Several organic solvents have been investigated in combination with water and acid/base catalysts; however, the lack of a holistic approach often compromises the performance of the different operational units. Thus, an economically viable organosolv process should optimize biomass fractionation, product isolation, and solvent recycling. [ABSTRACT FROM AUTHOR]

• Aqueous extraction with application of HVED was investigated (1st step). • Non-aqueous extraction from vacuum dried samples was applied (2nd step). • Preliminary washing and HVED favoured selective extraction of different bio-molecules. • HVED treatment improved kinetics of vacuum drying of microalgal biomass. Two-step procedure with the initial aqueous extraction from raw microalgae Nannochloropsis oculata and secondary organic solvent extraction from vacuum dried (VD) microalgae were applied for selective recovery of bio-molecules. The effects of preliminary aqueous washing and high voltage electrical discharges (HVED, 40 kV/cm, 4 ms pulses) were tested. The positive effects of HVED treatment and washing on selectivity of aqueous extraction of ionics and other water-soluble compounds (carbohydrates, proteins and pigments) were observed. Moreover, the HVED treatment allowed improving the kinetic of vacuum drying, and significant effects of HVED treatment on organic solvent extraction of chlorophylls, carotenoids and lipids were determined. The proposed two-step procedure combining the preliminary washing, HVED treatment and aqueous/organic solvents extraction steps are useful for selective extraction of different bio-molecules from microalgae biomass. [ABSTRACT FROM AUTHOR]

• Development of a sustainable process to maximise the potential of Dunaliella salina. • Recovery and fractionation of large diversity of compounds from Dunaliella salina. • Integrated approach involving REACH solvents and organic solvent nanofiltration. • Recovery of 94% of polar lipids, 85% of carotenoids and 86% of glycerol. • Economic evaluation provided an appealing ROI of 440% and an IRR of 53% Dunaliella salina is well-known for its high content in carotenoids and glycerol. Nevertheless, Dunaliella salina has also a high content in lipids, including polar lipids, which are suitable for nutraceutical/cosmeceutical applications. This work proposes a sustainable process to maximise the potential of Dunaliella salina for the production of distinct fractions of carotenoids, glycerol, polar lipids and proteins, which may contribute to improve the revenues of the microalgae industry. In this work, extraction with non-hazardous solvents and organic solvent nanofiltration are integrated, in order to obtain added-value products and glycerol. Also, aiming to separate carotenoids from glycerides, a saponification process is proposed. High overall recoveries were obtained for carotenoids (85%), glycerol (86%), polar lipids (94%) and proteins (95%). In order to evaluate the profitability of the proposed biorefinery, an economic assessment was accomplished. Both CAPEX and OPEX (Capital and Operating expenditure) were calculated, likewise the Return of Investment (ROI). [ABSTRACT FROM AUTHOR]

• Miniemulsion medium was employed for aldol reaction by Rhizopus niveus lipase. • Stable miniemulsion system was obtained for solid reagent and buffer solution. • Enzymatic stability increased when compared to conventional organic solvents. • Even reduced concentration of enzyme promoted increased yield in miniemulsion. • Simple protocol for miniemulsion destabilization and product isolation. Miniemulsion systems presented a great potential for biocatalytic reactions. However, different limitations jeopardized the applications of this non-conventional medium. In this work, miniemulsion systems (emulsion reactors) were applied for the first time to the aldol reaction between cyclohexanone and 4-nitrobenzaldehyde by Rhizopus niveus lipase allowing a decrease in the catalyst concentration from 20 mg mL−1 to 6 mg mL−1 in comparison with organic solvents. Moreover, the yield increased from ~25% to ~65% for 48 h reactions and the enantiomeric excess increased from ~10% to ~30% for (R,S)- anti -aldol product, showing the potentiality of this non-conventional reaction medium. The advances reported in this work expands the possibilities of the miniemulsion reaction medium to a whole new level, increasing the scope to solid reagents and products, and also different reactions (biocatalytic or not) that requires pH control by buffers with a simple product isolation procedure, enabling future applications of this poorly studied reaction medium. [ABSTRACT FROM AUTHOR]

• Multi-grade lignin can be obtained by solvent fractionation. • Different organic solvents have different proportions of dissolved lignin. • Lignin fractions have different physicochemical properties and hydroxyl content. • Microsphere with different surface morphologies was prepared from lignin fractions. Here we report a centrifugation-based fractionation methodology that was integrated with three types of organic solvents to fractionate industrial alkali lignin toward the fabrication of lignin microsphere. The Fourier-transform infrared spectroscopy (FT-IR) result showed that the chemical structure of lignin was not changed by solvent fractionation. Soluble lignin in each solvent had lower molecular weight, improved polydispersity index (PDI) and less impurities (S, N), while insoluble lignin had a high bio-char yield and can be utilized as potential carbon source for porous carbon nanosphere materials. In addition, well-shaped lignin microsphere with smooth or anisotropic surface can be prepared by selecting proper lignin fraction without any chemical modification. This work thus provides a new strategy for the derivation of lignin as raw materials for value-added products, which paved a new way to develop a green and sustainable bio-refining industry. [ABSTRACT FROM AUTHOR]

• Cefaclor yield of 91% was obtained in DES-buffer (7:3, v/v) co-solvent system. • Penicillin acylase immobilized on magnetic nanocrystalline cellulose was prepared. • The introduction of DES enhanced the yield and selectivity of cefaclor synthesis. Deep eutectic solvent (DES), has been considered as a new type of green solvent applied in enzymatic systems. Here, we reported DES-buffer co-solvent as a novel reaction medium for high efficient synthesis of cefaclor by penicilin acylase immobilized on magnetic nanocrystalline cellulose. Effect of DES composition, DES-buffer ratio, temperature, pH, substrate ratio and substrate concentration was systematically investigated. In co-solvent consisting of choline chloride (ChCl):glycol-buffer (7:3, v/v), conversion of 7-ACCA was 94%, synthesis to hydrolysis ratio was 1.8, and yield of cefaclor reached 91%, higher than that in aqueous buffer with optimized yield of 84%, showing the great potential of DES as organic solvent alternative. To the best of our knowledge, this is the first example of biosynthesis of cefaclor in the DES-buffer co-solvent. [ABSTRACT FROM AUTHOR]