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[Display omitted] • A broad-spectrum organic solvents tolerant strain STO was obtained by ALE. • Multi-omics integrated physiology of styrene oxide tolerant strain was analyzed. • GOX_RS04415 and GOX_RS04700 were considered as key genes for tolerance in G. oxydans. • The first report on the organic solvent tolerance mechanisms in G. oxydans. Chemical production wastewater contains large amounts of organic solvents (OSs), which pose a significant threat to the environment. In this study, a 10 g·L−1 styrene oxide tolerant strain with broad-spectrum OSs tolerance was obtained via adaptive laboratory evolution. The mechanisms underlying the high OS tolerance of tolerant strain were investigated by integrating physiological, multi-omics, and genetic engineering analyses. Physiological changes are one of the main factors responsible for the high OS tolerance in mutant strains. Moreover, the P-type ATPase GOX_RS04415 and the LysR family transcriptional regulator GOX_RS04700 were also verified as critical genes for styrene oxide tolerance. The tolerance mechanisms of OSs can be used in biocatalytic chassis cell factories to synthesize compounds and degrade environmental pollutants. This study provides new insights into the mechanisms underlying the toxicological response to OS stress and offers potential targets for enhancing the solvent tolerance of G. oxydans. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metabolic engineering in Pichia pastoris boosts phenol production. • Created a hollow fiber membrane contactor effective for extracting phenol. • Extracted phenol produced by P. pastoris from the fermentation medium. • Demonstrated the potential of pertraction in producing chemicals toxic to microbes. This study aimed to establish a high-level phenol bioproduction system from glycerol through metabolic engineering of the yeast Pichia pastoris (Komagataella phaffii). Introducing tyrosine phenol-lyase to P. pastoris led to a production of 59 mg/L of phenol in flask culture. By employing a strain of P. pastoris that overproduces tyrosine—a precursor to phenol—we achieved a phenol production of 1052 mg/L in glycerol fed-batch fermentation. However, phenol concentrations exceeding 1000 mg/L inhibited P. pastoris growth. A phenol pertraction system utilizing a hollow fiber membrane contactor and tributyrin as the organic solvent was developed to reduce phenol concentration in the culture medium. Integrating this system with glycerol fed-batch fermentation resulted in a 214 % increase in phenol titer (3304 mg/L) compared to glycerol fed-batch fermentation alone. These approaches offer a significant framework for the microbial production of chemicals and materials that are highly toxic to microorganisms. [ABSTRACT FROM AUTHOR]

[Display omitted] • The high yield of 5-HMF (61%) confirmed the effectiveness of the DESs based biphasic system. • BHC can replace traditional acid catalysts and ionic liquids because it is non-toxic and inexpensive. • AlCl 3 ·6H 2 O and BHC could be effectively reused four times. • CrCl 3 conjunction with BHC is a novel and promising strategy for the 5-HMF production from LCB. In this study, different types of lignocellulosic biomas were used as substrates for the conversion to 5-HMF via biphasic reaction system that is composed of a reaction phase (aqueous phase) and an extraction phase (organic phase) under the catalysis of various metal salts. Deep eutectic solvents (DESs), ionic liquid [BMIM]Cl, aqueous choline chloride, aqueous betaine hydrochloride, and ethylamine hydrochloride were used as the reaction phase in the combination of dimethyl sulfoxide (DMSO) as organic solvents. The highest yields of 5-HMF obtained from pineapple stems in reactions with DES were 40.98%, 37.26%, and 23.44% for ChCl:Lac, ChCl:OA, and EaCl:Lac, respectively. Moreover, the combination of dimethyl sulfoxide, betaine hydrochloride aqueous solution, and AlCl 3 ·6H 2 O with the pineapple stem conversion system resulted in a maximum yield of 61.04% ± 0.55% of 5-HMF. This study also demonstrated that AlCl 3 ·6H 2 O and betaine hydrochloride could be effectively reused four times, which indicates a green and effective process. [ABSTRACT FROM AUTHOR]

[Display omitted] • LiBr·3H 2 O/DCM treatment was evaluated for whole biomass fractionation and conversion. • 58.9% glucose and 72.5% furfural yielded in LiBr·3H 2 O/DCM system by one-step. • Residual lignin showed low molecular weights with high purity. • Morphological and topochemical changes of corn stalk were investigated. An effective approach for glucose and furfural production by converting cellulose and hemicelluloses from corn stalk in a biphasic system of molten salt hydrate (MSH) and organic solvent using H 2 SO 4 as catalyst was reported. Results showed that the system with LiBr·3H 2 O and dichloromethane (DCM) had excellent performance in cellulose and hemicelluloses conversion. Under the optimal reaction conditions (corn stalk:LiBr·3H 2 O:DCM ratio = 0.35:10:20 g/mL/mL, 0.05 mol/L H 2 SO 4 , 120 °C, 90 min), 58.9% glucose and 72.5% furfural were yielded. Meanwhile, lignin was obviously depolymerized by the cleavage of β -O-4′ linkages and fractionated with high purity and low molecular weight for potential coproducts. Fluorescence microscopy and confocal Raman microscope displayed that the LiBr·3H 2 O/DCM treatment caused decreasing intensities in carbohydrate and lignin, suggesting the degradation of the main components of biomass. This research provided a promising biorefinery technology for the comprehensive utilization of corn stalk. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photo-driven enzyme was firstly immobilized by affinity absorption. • An immobilization capacity of 98 mg/g carrier was achieved. • Hydrocarbon fuel production was achieved by immobilized photoenzyme. • High remaining enzyme activity after immobilization was observed. Fatty acid photodecarboxylase in Chlorella variabilis NC64A (Cv FAP) performed excellent ability to exclusively decarboxylate renewable fatty acids for C1-shortened hydrocarbons fuel production under visible light. However, the large-scale application by such an approach is limited by the free state of Cv FAP catalyst, which is unstable for efficient biofuel production. In this study, Cv FAP was immobilized in magnetic nickel ferrite (NiFe 2 O 4) nanoparticles for facile recovery by a simple procedure. The shift of Ni 2p in electron binding energy was detected to clarify the interaction between Ni2+ and histidine of Cv FAP. The coordination of NiFe 2 O 4 and Cv FAP contributed to an efficient affinity binding with an immobilization capacity of 98 mg/g carrier. Hydrocarbon fuel concentration of 3.7 mM was obtained by NiFe 2 O 4 @ Cv FAP-induced photoenzymatic decarboxylation. The high stability of Cv FAP in terms of residual enzyme activity of 79.7% at pH 9.0 and that of 68% at organic solvent ratio of 60%, respectively, were observed. [ABSTRACT FROM AUTHOR]

[Display omitted] • β-xylosidase and endoxylanase were co-immobilized on UiO-66-NH 2 by simple mixing. • Co-immobilized β-xylosidase showed enhanced activity at higher temperature. • Co-immobilized β-xylosidase showed better performances in high concentration of acetone. • 52% β-xylosidase and 70% endoxylanase activity were remained after five recycles. Improving the activity of β-xylosidase at high temperature and organic solvents is important for the conversion of xylan, phytochemicals and some hydroxyl-containing substances to produce xylose and bioactive substances. In this study, a β-xylosidase R333H and an endoxylanase were simultaneously co-immobilized on the metal–organic framework UiO-66-NH 2. Compared with the single R333H immobilization system, the co-immobilization enhanced the activity of R333H at high temperature and high concentration of acetone, and the relative activities at 95 °C and 50% acetone solution were >95%. The K m value of co-immobilized R333H towards p-Nitrophenyl-β-D-xylopyranoside (pNPX) shifted from 2.04 to 0.94 mM, which indicated the enhanced affinity towards pNPX. After 5 cycles, the relative activities of the co-immobilized enzymes towards pNPX and corncob xylan were 52% and 70% respectively, and the accumulated amount of reducing sugars obtained by co-immobilized enzymes degrading corncob xylan in 30% (v/v) acetone solution was 1.7 times than that with no acetone. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Biodiesel production from scum is more favorable than methane production. • Lipid extraction using organic solvents makes process energy intensive. • Sludge fortified crude glycerol reduces energy input at fermentation for microbial lipid production. • Lipid extraction using N-LS and Petroleum diesel is quick and less energy intensive. Abstract Biodiesel production using microbial oil is a promising technology. The main aim of this study is to check practical feasibility (in terms of energy balance) of different biodiesel production processes. Mass and energy balance of biodiesel production have been performed for 3 separate processes: (1) microbial lipid production from T. oleaginosus using waste substrates followed by INRS downstream process (2) microbial lipid production from pure substrate using R. toruloides followed by traditional and INRS downstream process and 3) oil extraction from scum and conversion to biodiesel. It was found that employing waste substrates like crude glycerol and municipal sludge in fermentation reduced the energy input by 50%. While employing biodegradable surfactants and petroleum-diesel as solvent (PD) for lipid extraction and recovery significantly reduced the energy input at cell wall disruption step. Biodiesel production from scum is a two-step process which is fast and energetically favorable. [ABSTRACT FROM AUTHOR]

[Display omitted] • The p-TsOH/2-MeTHF/H 2 O system was desirable for high selectivity fractionation. • 95.69% cellulose was retained as high removal of hemicellulose and lignin. • The hydrolysate was dehydrated into 80.07% furfural in the biphasic system. • The digestibility of residue was achieved at 95.82%. • 33.83% precipitated lignin could be obtained based on raw material. Developing an environmentally friendly and efficient pretreatment to utilize wheat straw is essential to a sustainable future. An acid biphasic system with 2-methyltetrahydrofuran (2-MeTHF) organic solvent and dilute p-toluenesulfonic acid (p-TsOH) were employed for the simultaneous fractionation of three components. Results showed that the biphasic system had excellent cellulose protection and high removal of hemicellulose and lignin. In detail, Under the optimal conditions (0.1 M p-TsOH, 2-MeTHF: H 2 O = 1:1 (v:v), 140 °C, 3 h), mostly cellulose retained in the residues (95.69%), 57.18% of lignin was removed and high yield of hemicellulose-based C5 sugars was achieved (77.49%). In the further process of dehydration of pre-hydrolysate dichloromethane (DCM) as an organic phase, the yield of furfural was 80.07% (170 °C–80 min). The saccharification of residue reached 95.82%. p-TsOH/2-MeTHF/H 2 O pretreatment was desirable for high selectivity fractionation. Important chemicals for bioenergy including furfural, monosaccharides and lignin are obtained. [ABSTRACT FROM AUTHOR]

[Display omitted] • Using SPR to elucidate how pseudo-lignin inhibits enzymatic hydrolysis. • The adsorption–desorption process of pseudo-lignin and cellulase was explored. • Key factors of pseudo-lignin affecting the enzymatic digestibility of cellulose. To explore the interaction mechanism of pseudo-lignin (PL) with cellulase and its influence on cellulose hydrolysis, different PLs were extracted from pretreated bamboo holocellulose (HC) using different organic solvents. Meanwhile, the real-time interaction of PL and cellulase was analyzed using surface plasmon resonance (SPR). The results showed that the extraction effect of the tetrahydrofuran and 1, 4-dioxane/water solution on PL was more effective than the ethanol/water solution. The inhibition of PL fraction obtained from HC by acid pretreatment with higher temperature showed less effect on Avicel's enzymatic hydrolysis. SPR analysis revealed that PL formed at higher pretreatment temperature had a lower dissociation rate after adsorption with cellulase. Besides, the binding affinity of PL (160 °C) to cellulase was much greater than that of PL obtained from 180 °C, indicating PL extracted at higher temperature treated biomass is more easily dissociated from cellulase after binding. [ABSTRACT FROM AUTHOR]

[Display omitted] • Poplar was pretreated by reusable organic solvent under mild temperature (≤100 °C). • Almost all hemicelluloses and part of lignin was extracted with cellulose retained. • Sulfonic acid groups were introduced into lignin structure remained in substrates. • 89% improved glucose conversion compared with that of non-sulfonated substance. • New strategy is exploited to realize sulfonation and promote biomass bioconversion. Biomass pretreatment is an essential strategy to overcome biomass recalcitrance and promote lignocellulosic bioconversion. Here, a reusable organic solvent system (formic acid-methanesulfonic acid) was explored to pretreat poplar under a mild temperature (below 100 °C). The results showed that the co-solvent system could extract basically complete hemicelluloses and part of lignin with original cellulose retained in the pretreated substrates. Meanwhile, sulfonic acid groups were introduced into lignin structure remained in the substrates. The glucose conversion yield of the substrates with a higher concentration of sulfonic acid groups (13.2 mmol/kg) reached 45.9 % by reducing the hydrophobic interaction between lignin and cellulase, showing 89.3 % improvement compared with that of the substrates treated with single formic acid. This progressive study aimed to develop a new strategy to realize sulfonation and promote enzymatic hydrolysis of substrates by using mild organic solvent pretreatment. [ABSTRACT FROM AUTHOR]

A novel and efficient organic amine and organosolv synergetic pretreatment method was developed to overcome the recalcitrance of lignocellulose to produce fermentable sugars and high-quality salt-free lignin. After optimization of the process parameters, a delignification of 81.7% and total sugar yield of 83.2% (87.1% glucose, 75.4% xylose) could be obtained using n -propylamine (10 mmol/g, biomass) as a catalyst and aqueous ethanol (60%, v/v) as a solvent. The susceptibility of the substrates to enzymatic digestibility was explained by their physical and chemical characteristics. The physical structure of extracted lignin showed higher β -aryl ether bonds content and functionalities, offering the potential for further downstream upgrading. The role of organic amine catalyst and a synergistic mechanism is proposed for the present system. [ABSTRACT FROM AUTHOR]

Anaerobic treatment of wastewater and waste organic solvents originating from the pharmaceutical and chemical industries was tested in a pilot anaerobic membrane bioreactor, which was operated for 580 days under different operational conditions. The goal was to test the long-term treatment efficiency and identify inhibitory factors. The highest COD removal of up to 97% was observed when the influent concentration was increased by the addition of methanol (up to 25 g L −1 as COD). Varying and generally lower COD removal efficiency (around 78%) was observed when the anaerobic membrane bioreactor was operated with incoming pharmaceutical wastewater as sole carbon source. The addition of waste organic solvents (>2.5 g L −1 as COD) to the influent led to low COD removal efficiency or even to the breakdown of anaerobic digestion. Changes in the anaerobic population (e.g., proliferation of the genus Methanosarcina ) resulting from the composition of influent were observed. [ABSTRACT FROM AUTHOR]

Catalytic conversion of corncob pretreatment hydrolysate and raw corncob into furfural in a modified biphasic system by SO 4 2− /SnO 2 − MMT solid catalyst has been developed. The influence of the organic solvent type, organic to water phase ratio, sodium chloride concentration, reaction temperature and time on the furfural production were comparatively evaluated. The results showed that furfural yields of 81.7% and 66.1% were achieved at 190 °C for 15 mins and 190 °C for 20 mins, respectively, for corncob pretreatment hydrolysate and raw corncob by this solid catalyst. The solid catalyst used in this study exhibited good stability and high efficiency applied in the modified biphasic system in addition to excellent recyclability. The proposed catalytic system displayed high performance for catalytic conversion of lignocellulosic biomass into important platform chemicals and has great potential in industrial application. [ABSTRACT FROM AUTHOR]

This work addresses in-situ transesterification of wet spent coffee grounds (SCGs) for the production of biodiesel. For in-situ transesterification process, the methanol, organic solvent and acid catalyst were mixed with wet SCG in one pot and the mixture was heated for simultaneous lipid extraction and transesterification. Maximum yield of fatty acid methyl esters (FAME) was 16.75 wt.% based on the weight of dry SCG at 95 °C. Comprehensive experiments were conducted with varying temperatures and various amounts of moisture, methanol, co-solvent and acid catalyst. Moderate polar and alcohol-miscible organic solvent is suitable for the high FAME yield. Unsaturated FAMEs are subject to oxidative cleavage by nitric acid and shorter chain (C6 and C10) FAMEs were mainly produced while sulfuric acid yielded long chain unsaturated FAMEs (C16 and C18). Utilization of wet SCGs as a biodiesel feedstock gives economic and environmental benefits by recycling the municipal waste. [ABSTRACT FROM AUTHOR]

A two stage pretreatment approach for biomass is developed in the current work in which dilute acid (DA) pretreatment is followed by a solvent based pretreatment (N-methyl morpholine N oxide – NMMO). When the combined pretreatment (DAWNT) is applied to sugarcane bagasse and corn stover, the rates of hydrolysis and overall yields (>90%) are seen to dramatically improve and under certain conditions 48 h can be taken off the time of hydrolysis with the additional NMMO step to reach similar conversions. DAWNT shows a 2-fold increase in characteristic rates and also fractionates different components of biomass – DA treatment removes the hemicellulose while the remaining cellulose is broken down by enzymatic hydrolysis after NMMO treatment to simple sugars. The remaining residual solid is high purity lignin. Future work will focus on developing a full scale economic analysis of DAWNT for use in biomass fractionation. [ABSTRACT FROM AUTHOR]

The surface characterization and chemical analysis of bamboo substrates by alkali hydrogen peroxide pretreatment (AHPP) were investigated in this study. The results tended to manifest that AHPP prior to enzymatic and chemical treatment was potential for improving accessibility and reactivity of bamboo substrates. The inorganic components, organic solvent extractives and acid-soluble lignin were effectively removed by AHPP. X-ray photoelectron spectroscopy (XPS) analysis indicated that the surface of bamboo chips had less lignin but more carbohydrate after pre-treatment. Fiber surfaces became etched and collapsed, and more pores and debris on the substrate surface were observed with Scanning Electron Microscopy (SEM). Brenauer-Emmett-Teller (BET) results showed that both of pore volume and surface area were increased after AHPP. Although XRD analysis showed that AHPP led to relatively higher crystallinity, pre-extraction could overall enhance the accessibility of enzymes and chemicals into the bamboo structure. [ABSTRACT FROM AUTHOR]

High moisture content in wet algal biomass hinders effective performance of current lipid extraction methods. An improved aqueous extraction method combing thermal and enzymatic lysis was proposed and performed in algal slurry of Nannochloropsis oceanica (96.0% moisture) in this study. In general, cell-wall of N. oceanica was disrupted via thermal lysis and enzymatic lysis and lipid extraction was performed using aqueous surfactant solution. At the optimal conditions, high extraction efficiencies for both lipid (88.3%) and protein (62.4%) were obtained, which were significantly higher than those of traditional hexane extraction and other methods for wet algal biomass. Furthermore, an excessive extraction of polar lipid was found for wet biomass compared with dry biomass. The advantage of this method is to efficiently extract lipids from high moisture content algal biomass and avoid using organic solvent, indicating immense potential for commercial microalgae-based biofuel production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Removal of silica and lignin from rice straw under mild conditions is investigated. • High silica (92%) removal from rice straw in the presence of aqueous NH 3 is achieved. • High removal of lignin (60%) with NH 3 in water-THF solvent is obtained. • Parent rice straw affords 8- and 4-fold lower yields of furfural and levulinic acid. • Removal of silica/lignin improves the productive rate of target products. The intricate nature and rigidity of rice straw, particularly the presence of lignin and silica, hinders the catalytic valorization, consequently decreasing the yield of target products. This study reports the concurrent removal of lignin and silica from rice straw to obtain enriched holocellulose, then transforming it to furfural (FUR) and levulinic acid (LA). Interestingly, rice straw in the form of powder displays an improved removal of lignin (51.0%) and silica (92.0%) during ammonia treatment. Encouragingly, adding organic solvents, such as THF, to the aqueous system during the pretreatment of rice straw improves the lignin removal to 60.0%. Upon improving lignin removal to 60%, the obtained holocellulose enriched solid residue yields 71.0% FUR along with 52.0% LA, which is 8 and 4-fold higher than what is obtained with parent rice straw, signifying the importance and the prerequisite of lignin and silica removal from rice straw. [ABSTRACT FROM AUTHOR]

Protocols were developed for efficient release of glucose from the biomass of Senna siamea , one of the highly efficient biomass producing tree legumes. Composition of mature, 1 year and 2 years coppice biomass were analysed. For the hydrolysis of the glucan, two pretreatments, cellulose solvent- and organic solvent-based lignocellulose fractionation (COSLIF) and alkali (sodium hydroxide) were used; COSLIF (85% phosphoric acid, 45 min incubation at 50 °C) pretreated mature biomass exhibited best result in which 88.90% glucose released after 72 h of incubation with the use of 5 filter paper units (FPU) of cellulase and 10 international units (IU) of β -glucosidase per gram of glucan. Of the biomass of different particle sizes (40–200 mesh) used for saccharification, 40–60 mesh shown the maximum glucose release. COSLIF pretreated mature, 1 year and 2 years coppice biomass showed equivalent glucose release profiles. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass represents the largest potential volume and lowest cost for biofuel and biochemical production. Pretreatment is an essential component of biomass conversion process, affecting a majority of downstream processes, including enzymatic hydrolysis, fermentation, and final product separation. Organic solvent pretreatment is recognized as an emerging way ahead because of its inherent advantages, such as the ability to fractionate lignocellulosic biomass into cellulose, lignin, and hemicellulose components with high purity, as well as easy solvent recovery and solvent reuse. Objectives of this review were to update and extend previous works on pretreatment of lignocellulosic biomass for biofuels and biochemicals using organic solvents, especially on ethanol, methanol, ethylene glycol, glycerol, acetic acid, and formic acid. Perspectives and recommendations were given to fully describe implementation of proper organic solvent pretreatment for future research. [ABSTRACT FROM AUTHOR]

The lipid extractability of 14 microalgae species and strains was assessed using organic solvents (methanol and chloroform). The high variability detected indicated the potential for applying this parameter as an additional criterion for microalgae screening in industrial processes such as biofuel production from microalgae. Species without cell walls presented higher extractability than species with cell walls. Analysis of cell integrity by flow cytometry and staining with propidium iodide showed a significant correlation between higher resistance to the physical treatments of cell rupture by sonication and the lipid extractability of the microalgae. The results highlight the cell wall as a determining factor in the inter- and intraspecific variability in lipid extraction treatments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Furfural was produced in an aqueous choline chloride-maleic acid/toluene medium. • Tin-loaded sulfonated carbonaceous solid acid was prepared for furfural production. • 82.6% of furfural yield was achieved using the carbonaceous solid acid catalyst. • Full utilization of biomass components for furfural production. • The catalytic reaction system has good reusability. Sunflower stalk was utilized as a source of raw material and catalyst for furfural production, and efficient conversion of xylose-rich hydrolysate into furfural was developed in an aqueous deep eutectic solvent/organic solvent medium by carbonaceous solid acid catalyst SO 4 2−/SnO 2 -SSXR. The structural characteristics of SO 4 2−/SnO 2 -SSXR was characterized by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Fourier-transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Pyridine Adsorption Fourier-transform Infrared (Py-IR) and Raman. Under the optimum catalytic conditions, furfural (110.1 mM) yield reached 82.6% in a ChCl-MAA/toluene medium at 180 °C in 15 min by 3.6 wt% SO 4 2−/SnO 2 -SSXR. Additionally, quite importantly, SO 4 2−/SnO 2 -SSXR, ChCl-MAA and toluene had good recyclability for furfural production. The potential catalytic path of xylose dehydration into furfural was proposed by co-catalysis with SO 4 2−/SnO 2 -SSXR and ChCl-MAA. This study revealed high potential sustainable application of furfural production. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction of rice straw has been carried out using various organic solvents (CH 3 OH, C 2 H 5 OH) at different temperatures (250, 280 and 300 °C) and residence times (15, 30 and 60 min) to understand the effect of solvent and various reaction parameters on product distribution. Maximum liquid product yield (47.52 wt%) was observed using ethanol at 300 °C and 15 min reaction time. FTIR and NMR ( 1 H and 13 C) of liquid product indicate that lignin in rice straw was converted to various monomeric phenols. GC–MS of the liquid product showed the presence of various phenol and guaiacol derivatives. Main compounds observed in liquid product were phenol, 4-ethylphenol, 4-ethyl-2-methoxyphenol (4-ethylguaiacol), 2,6-dimethoxyphenol (syringol), 2-isopropyl-5-methylphenol (thymol). Powder XRD and SEM of bio-residue showed that rice straw was decomposed to low molecular weight monomeric phenols. [ABSTRACT FROM AUTHOR]

This study aimed to produce furfural from waste aqueous hemicellulose solution of a hardwood kraft-based dissolving pulp production processing in a green method. The maximum furfural yield of 82.4% and the xylose conversion of 96.8% were achieved at 463 K, 1.0 g ZSM-5, 1.05 g NaCl and organic solvent-to-aqueous phase ratio of 30:15 (V/V) for 3 h. The furfural yield was just 51.5% when the same concentration of pure xylose solution was used. Under the optimized condition, furfural yield was still up to 67.1% even after the fifth reused of catalyst. Catalyst recycling study showed that ZSM-5 has a certain stability and can be efficiently reused. [ABSTRACT FROM AUTHOR]

Complex waste streams originating from extraction processes containing residual organic solvents and increased C/N ratios have not yet been considered as feedstock for biogas production to a great extent. In this study, spent rosehip ( Rosa canina L.) solid residue (64% VS, 22 MJ/kg HHV, 30 C /1 N ) was obtained from an industrial ethanol aided extraction process, and extensively examined in an automated batch bioreactor system for biogas production. Fraction separation of the compact lignocellulosic seeds increased the available sugar and ethanol content, resulting in high biogas potential of the sieved residue (516 NL/kg VS’). In co-digestion of spent rosehip substrate with non-deactivated nitrogen rich microbial co-substrates, methanogenesis was favored ( Y m > 68 % CH 4 ). In individual digestion of microbial co-substrates, this was not the case, as biogas with 28 vol.% N 2 was produced from activated sludge supplement. Therefore, effective inhibition of exogenous microbiota was achieved in the presence of carbonaceous spent rose hip. [ABSTRACT FROM AUTHOR]

The β-xylosidase encoding gene ( XsidB ) of the extremely thermophilic bacterium Geobacillus thermodenitrificans has been cloned and expressed in Escherichia coli. The homotrimeric recombinant XsidB is of 204.0 kDa, which is optimally active at 60 °C and pH 7.0 with T 1/2 of 58 min at 70 °C. The β-xylosidase remains unaffected in the presence of most metal ions and organic solvents. The K m [p-nitrophenyl β-xyloside (pNPX)], V max and k cat values of the enzyme are 2 × 10 −3 M, 1250 μmoles mg −1 min −1 and 13.20 × 10 5 min −1 , respectively. The enzyme catalyzes transxylosylation reactions in the presence of alcohols as acceptors. The pharmaceutically important β-methyl- d -xylosides could be produced using pNPX as the donor and methanol as acceptor. The products of transxylosylation were identified by TLC and HPLC, and the structure was confirmed by 1 H NMR analysis. The enzyme is also useful in synthesizing transxylosylation products from the wheat bran hydrolysate. [ABSTRACT FROM AUTHOR]

Milled Onopordum heteracanthum stalks were converted to liquid products in organic solvents (methanol, ethanol and acetone) with (KOH and ZnCl2) and without catalyst in an autoclave at temperatures of 523, 543 and 563 K. Effects of liquefaction parameters such as catalyst and solvent were investigated. The percentage yields from supercritical methanol, ethanol and acetone conversions were 48.2, 50.4 and 66.2 at 563 K in the non-catalytic runs, respectively. In the catalytic run with ZnCl2, the highest conversion (70.2%) was obtained in acetone at the same temperature. The obtained liquid products at 563 K were analyzed and characterized by elemental, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry. 106 different compounds have been identified by GC–MS in the liquid products obtained in methanol at 563 K. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two novel ionic liquid tolerant cellulases were discovered from metagenomic data. • The stability of the cellulases is enhanced in the presence of ionic liquid. • Ionic liquid-activated rice straw was enzymatically hydrolyzed in the one-pot system. Ionic liquids (ILs)-resistant cellulase enzymes can facilitate the saccharification of IL- pretreated biomass in a one-pot wash-free method. Using a bioinformatics approach, two cellulases, Persicel7 and Persicel8, with convincing evidence for ionic liquid tolerance were identified. Subsequently, these enzymes were heterologously expressed and biochemically characterized. Persicel7 and Persicel8 exhibited endo -β-1, 4-glucanase activity and were resistant to inhibitors and several organic solvents. Their activity in 10% (v/v) 1-ethyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium chloride were 130% higher compared with IL-free control. The half-life of cellulases was improved up to 11-fold when incubated with 20% (v/v) solution of ion liquids. In addition, a one-pot IL-pretreatment and enzymatic saccharification of rice straw enhanced the saccharification rate by 33% compared to the untreated reaction. The Persicel7 and Persicel8 unique properties make them attractive candidates for industrial applications, particularly hydrolyzing ion liquid activated biomass in a one-pot system. [ABSTRACT FROM AUTHOR]

Highlights: [•] Free nitrous acid (FNA) pretreatment enhances lipid extraction yield from algae. [•] FNA pretreatment boosts mass transfer coefficient of lipid extraction significantly. [•] FNA at ppm level can cause algal cell envelope (wall and membrane) disruption. [•] Cell disruption is not accompanied by lipid release. [•] Algal cell envelope disruption contributes to lipid extraction by organic solvent. [ABSTRACT FROM AUTHOR]

Highlights: [•] This provides basic information ascertaining promising solvents for the recovery. [•] Some organic solvents are effective to recovery ionic liquid and obtain lignin. [•] The effective order is isopropanol>ethanol>acetonitrile>ally alcohol>methanol. [Copyright &y& Elsevier]

Highlights: [•] Nanofiltration can enrich the phenolic substances in the WWS of SECS. [•] Successively organic solvent extraction can separate materials in WWS effectively. [•] Organic solvent extractive of WWS could act as natural mediator for laccase. [•] Laccase/EE can decolorize crystal violet more efficiently than laccase/ABTS. [•] This work would benefit for reducing the cost of laccase-mediator system. [ABSTRACT FROM AUTHOR]

In this work, the conceptual designs of the established Organosolv process and a novel biphasic, so-called Organocat process are developed and analyzed. Solvent recycling and energy integration are emphasized to properly assess economic viability. Both processes show a similar energy consumption (approximately 5 MJ/kg dry biomass ). However, they still show a lack of economic attractiveness even at larger scale. The Organocat process is more favorable due to more efficient lignin separation. The analysis uncovers the remaining challenges toward an economically viable design. They largely originate from by-products formation, product isolation, and solvent recycling. Necessary improvements in process chemistry, equipment design, energy efficiency and process design are discussed to establish economically attractive Organosolv-like processes of moderate capacity as a building block of a future biorefinery. [ABSTRACT FROM AUTHOR]

The wide number of industrial processes applying cellulases highlights the importance of discovering robust enzymes able to work under harsh conditions. In this study, carboxymethyl cellulase (CMCase) activity of Paenibacillus tarimensis was characterized. A high activity was observed in pH range 3.0–10.5 and 9 mM–5 M NaCl. In high salt buffer at 80 °C, >80% and >76% of relative activity was retained at 20% of the ionic liquids (ILs) [EMIM]Ac and [BMIM]Cl; while >40% was detected with 40% [BMIM]Cl. Five CMCases were detected by renaturing SDS–PAGE. Their activity was retained in presence of 1.7 up to 5 M NaCl (for CMC1) or 4.6 M KCl; 5% organic solvents or 10 mM bivalent ions, EDTA and heavy metals; under neutral and halo-alkaline conditions. These cellulases stabile and highly functional under harsh conditions are promising candidates for application in detergents, textiles, paper/pulp industry; and simultaneous ILs treatment-saccharification of lignocellulose. [ABSTRACT FROM AUTHOR]

Highlights: [•] SML is an organic solvent-tolerant lipase. [•] It is a cold-active lipase. [•] Partially purified lipase showed the preference on medium- and long-chain esters. [•] High activity and stability of partially purified SML occur at alkaline condition. [Copyright &y& Elsevier]

Hydrolysis of lipids from microalgae under high water content was investigated as a pretreatment of direct esterification. Results indicated that the hydrolysis process reduced the inhibition by water in FAME production; in addition, FAME obtained by esterification of hydrolysates was increased by 181.7% compared to FAME obtained by direct transesterification under the same amount of water content (80%). This method has great potential in terms of biodiesel production from microalgae since it uses no organic solvent, reduces the drying cost and lowers the operating cost compared to any other traditional method. [ABSTRACT FROM AUTHOR]

Highlights: [•] A virulence factor (EfEstA) from Enterococcus faecalis was identified and characterized. [•] EfEstA showed high stabilities against salts, detergents, and organic solvents. [•] CLEAs of EfEstA exhibited improved stabilities with high recycling abilities. [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]

Highlights: [•] [Ch][Lys]-water mixtures as highly effective solvents for rice straw pretreatment. [•] A clear correlation between the medium basicity and its delignification capacity. [•] Substantial increase in surface area and pore volume of rice straw after pretreatment. [•] Good sugar yields in the enzymatic digestion of the biomass upon pretreatment. [•] Great application potential of this pretreatment process due to a lot of advantages. [Copyright &y& Elsevier]

A novel esterase, rPPE01, from Pseudomonas putida ECU1011 was heterologously expressed in Escherichia coli and identified for enzymatic resolution of hydroxy acids via O-deacetylation. α-Acetoxy carboxylates were converted with approximately 50% yield and excellent enantioselectivity (E >200) at a substrate concentration of 100mM. The half-lives of rPPE01 were 14days at 50°C and 30days at 30°C, indicating the enzyme has relatively high thermostability. Another remarkable advantage of rPPE01 is that both the activity and thermostability were enhanced significantly in the presence of hydrophobic alkanes and ethers. rPPE01 retained 159% of its initial activity after incubation with 50% (v/v) n-heptane at 30°C for 60days. The attractive organic-solvent tolerance, good thermostability and high enantioselectivity towards α-acetoxy carboxylates endow rPPE01 with the potential of practical application for the production of enantiopure hydroxy acids. [ABSTRACT FROM AUTHOR]

Abstract: An efficient enzymatic synthesis of endomorphin-2 (EM-2) was achieved using organic solvent stable proteases in nonaqeous media, based on thermodynamic control and an in situ product removal methodology. The high stability of biocatalysts in organic solvents enabled the aleatoric modulation of the nonaqueous reaction media to shift thermodynamic equilibrium toward synthesis. Peptide Boc-Phe-Phe-NH2 was synthesized with a high yield of 96% by the solvent stable protease WQ9-2 in monophase medium with an economical molar ratio of the substrate of 1:1. The tetrapeptide Boc-Tyr-Pro-Phe-Phe-NH2 was synthesized with a yield of 88% by another organic solvent tolerant protease PT121 from Boc-Tyr-Pro-OH and Phe-Phe-NH2 in an organic–aqueous biphasic system. The reaction–separation coupling in both enzymatic processes provides “driving forces” for the synthetic reactions and gives a high yield and high productivity without purification of the intermediate, thereby making the synthesis more amenable to scale-up. [Copyright &y& Elsevier]

Abstract: An effective approach was successfully developed to isolate glycosidase with resistance of hydrophilic organic solvent, simultaneously with acceptor specificity of the target substrate. By this approach, an efficient solvent tolerant glycosidase producing bacterium Arthrobacter nicotianae XM6 was obtained. The β-fructosidase from strain XM6 shows high activity and stability in 10–25% DMSO and 10–20% methanol with 90–99% yields of puerarin glycosides. The addition of hydrophilic solvents not only greatly promoted the solubility of puerarin, but also regulated main products from multifructosyl puerarin to monofructosyl puerarin with increasing solvent concentration. Extraordinary highly efficient synthesis of puerarin glycosides (111.3g/L of monofructosyl puerarin and 35.6g/L of difructosyl puerarin) was attained in 25% DMSO solvent system from 110.4g/L puerarin, which resulted a great facility for purification in large-scale process. The most novelty was that the β-fructosidase did not hydrolyze almost the newly formed glycosides using simply sucrose as donor. [Copyright &y& Elsevier]

Abstract: Developing feedstock-independent biomass pretreatment would be vital to second generation biorefineries that would fully utilize diverse non-food lignocellulosic biomass resources, decrease transportation costs of low energy density feedstock, and conserve natural biodiversity. Cellulose solvent- and organic solvent-based lignocellulose fractionation (COSLIF) was applied to a variety of feedstocks, including Miscanthus, poplar, their mixture, bagasse, wheat straw, and rice straw. Although non-pretreated biomass samples exhibited a large variation in enzymatic digestibility, the COSLIF-pretreated biomass samples exhibited similar high enzymatic glucan digestibilities and fast hydrolysis rates. Glucan digestibilities of most pretreated feedstocks were ∼93% at five filter paper units per gram of glucan. The overall glucose and xylose yields for the Miscanthus:poplar mixture at a weight ratio of 1:2 were 93% and 85%, respectively. These results suggested that COSLIF could be regarded as a feedstock-independent pretreatment suitable for processing diverse feedstocks by adjusting pretreatment residence time only. [Copyright &y& Elsevier]

Abstract: Ionic liquids (ILs) are promising solvents for the pretreatment of lignocellulose as they are thermally stable, environmentally friendly, recyclable, and have low volatility. This study evaluated the effect of 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) for the pretreatment of energy cane bagasse in terms of biomass composition, structural changes and enzymatic digestibility. Energy cane bagasse was pretreated with [EMIM][OAc] (5% (w/w)) at 120°C for 30min followed by hydrolysis with commercially available enzymes, Spezyme CP and Novozyme 188. IL-treated energy cane bagasse resulted in significant lignin removal (32.0%) with slight glucan and xylan losses (8.8% and 14.0%, respectively), and exhibited a much higher enzymatic digestibility (87.0% and 64.3%) than untreated (5.5% and 2.8%) or water-treated (4.0% and 2.1%) energy cane bagasse in terms of both cellulose and hemicellulose digestibilities, respectively. The enhanced digestibilities of IL-treated biomass can be attributed to delignification and reduction of cellulose crystallinity as confirmed by FTIR and XRD analyses. [Copyright &y& Elsevier]

Abstract: Production of bio-oil by microwave-assisted direct liquefaction (MADL) of Ulva prolifera was investigated, and the bio-oil was analyzed by elementary analysis, Fourier transform infrared spectroscopic analysis (FT-IR), and gas chromatography–mass spectrometry (GC–MS). The results indicate that the liquefaction yield is influenced by the microwave power, liquefaction temperature, liquefaction time, catalyst content, solvent-to-feedstock ratio and moisture content. The maximum liquefaction yield of U. prolifera (moisture content of 8%) was 84.81%, which was obtained under microwave power of 600W for 30min at 180°C with solvent-to-feedstock ratio of 16:1 and 6% H2SO4. The bio-oil was composed of benzenecarboxylic acid, diethyl phthalate, long-chain fatty acids (C13 to C18), fatty acid methyl esters and water. The results suggest that U. prolifera is a viable eco-friendly, green feedstock substitute for biofuels and chemicals production. [Copyright &y& Elsevier]

Abstract: Glucose was converted into furans (5-hydroxymethylfurfural and 5-ethoxymethylfurfural) in the presence of AlCl3 in an ethanol–water solvent system. The system showed high activity for the conversion of glucose into furans but low activity for the subsequent formation of LAs (levulinic acid and ethyl levulinate). High furans yield of 57% with low LAs yield of 11% can be obtained at 160°C within 15min. Glucose-based disaccharides (sucrose, maltose and cellobiose) and polysaccharides (starch but not cellulose) can also be converted to furans effectively under the same condition. AlCl3 can be used to prepare furans from biomass-derived compounds in ethanol–water, a green solvent system. [Copyright &y& Elsevier]

Abstract: Maltooligosaccharides especially maltotriose and maltotetraose producing amylases are highly desirable for application in bread making and other food industries. A maltotriose and maltotetraose producing amylase from moderately halophilic Marinobacter sp. EMB8 is described. Under optimized culture conditions, 48.0IU/mL amylase was obtained. The enzyme was purified to homogeneity by ultrafiltration, DEAE cellulose and Sephadex G-75 column chromatography with 52% yield and 76-fold purification. It was a monomeric protein of 72kDa. The amylase had many novel features viz. stability up to 20% NaCl, 80°C temperature, pH 6.0–11.0 and in wide range of organic solvents at high concentrations. The enzyme efficiently hydrolyzed starch into maltooligosaccharides rich in maltotriose and maltotetraose. These novel properties make the Marinobacter sp. amylase a potentially useful enzyme. [Copyright &y& Elsevier]

Abstract: In this study, an esterase, designated EstC23, was isolated from a soil metagenomic library. The protein was amenable to overexpression in Escherichia coli under control of the T7 promoter, resulting in expression of the active, soluble protein that constituted 30% of the total cell protein content. This enzyme showed optimal activity at 40°C and retained about 50% maximal activity at 5–10°C. EstC23 showed remarkable stability in up to 50% (v/v) benzene and alkanes (high log P solvents). When incubated for 7days in the presence of 50% benzene or alkanes, the enzyme maintained its 2–3 fold elevated activity. The purified enzyme also cleaved sterically hindered esters of tertiary alcohols. These results indicate that EstC23 has potential for use in industrial processes. [Copyright &y& Elsevier]

Abstract: Cross-linked enzyme aggregates of poly-3-hydroxybutyrate (PHB) depolymerase from Streptomyces exfoliatus (PhaZ Sex–CLEAs) have been prepared. Acetone was used as the precipitating agent, while addition of bovine serum albumin (BSA) facilitated CLEAs formation. Conditions for enzyme precipitation and cross-linking have been optimized, and confocal scanning microscopy showed a homogeneous enzyme distribution in the biocatalyst. Obtained PhaZ Sex –CLEAs presented an average size of 50–300μm, showing a high PHB depolymerase activity of 255U/g wet biocatalyst at 40°C and pH 7.0. Temperature-activity profile of PhaZ Sex –CLEAs at pH 8.0 showed that the highest activity for pNPB hydrolysis was achieved at 60°C, whereas pH-activity profile at 40°C indicated that highest activity for PHB hydrolysis was achieved at pH 7.0. Additionally, immobilized biocatalyst could be recycled at least for 20 consecutive batch reactions without loss of catalytic activity, and showed higher pH and temperature stability, and better tolerance to several organic solvents than its soluble counterpart. [Copyright &y& Elsevier]

Abstract: Magnetic iron oxide nanoparticles were loaded onto the surfaces of multiwalled carbon nanotubes (MWNTs) by the impregnation method. The obtained magnetic nanotubes were characterized with high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Yarrowia lipolytica lipase was covalently immobilized on the magnetic MWNTs (M-MWNTs). M-MWNT-lipase was characterized with XPS spectra and XRD patterns. The structural change of the immobilized lipase was analyzed through circular dichroism spectroscopy. M-MWNT-lipase was utilized for the resolution of (R, S)-1-phenyl ethanol in the organic solvent of heptane. Compared to the native lipase, the lipase immobilized on M-MWNTs has significantly improved its enzymatic activity for the resolution of (R, S)-1-phenyl ethanol in heptane. M-MWNT-lipase can be easily recovered after catalysis. In addition, the effect of sonication time on the catalytic activity was also investigated. It is found that, up to 30min sonication, the catalysis by M-MWNT-lipase is almost not affected. While, the catalytic activity of the native lipase is decreased with sonication time. [Copyright &y& Elsevier]