Solubilization Method Research Articles

Aqueous fractionation of mucilage and protein from Camelina sativa seeds and defatted meal

Camelina protein and mucilage are being investigated as coproducts in addition to the oil. It has been reported that the significant amount of mucilage (10–11 %) in the seed coat interferes with the recovery of the protein. In this work, two schemes of producing mucilage and protein fractions from camelina seeds were evaluated and proximate composition of each process stream was analyzed. In the sequential extraction process, mucilage was first separated from hydrated seeds, then oil from degummed seeds, and lastly the protein from the defatted degummed meal. In the other process, aqueous fraction rich in protein and carbohydrates were extracted simultaneously from defatted meal. Proteins were obtained by alkali solubilization and acid precipitation method. Sequential extraction produced a mucilage fraction with 15.2 % protein content and a protein isolate (90.2 % crude protein). Simultaneous aqueous extraction of the defatted meal produced a mucilage fraction with 48.9–50.2 % protein content and a protein concentrate (67.4 and 75.6 % crude protein). The whey obtained had similar protein and soluble carbohydrates contents of 24.4–26.4 % and 56.5–58.2 %, respectively. The difference in composition of the mucilage, protein and whey fractions produced by each process will determine the applications of these products.

Characterization of industrial pea canning by-product and its protein concentrate obtained by optimized ultrasound-assisted extraction

This work aimed to optimize protein extraction from an industrial pea canning by-product by developing an ultrasound-assisted alkaline solubilization and isoelectric precipitation method. Proximate composition and microbial contamination (total bacterial count, total lactic acid bacteria, Enterobacteriaceae, yeasts and moulds) were assessed in the wet by-product. The protein concentrate obtained, the dry by-product and a commercial pea flour were analysed for protein content, water activity, colour and techno-functional properties. The optimal extraction conditions from the wet by-product were liquid-solid ratio 20 mL/g, pH 11, ultrasound amplitude 80 μm, time 2 × 30 min. The extraction from the dry by-product was not feasible. Sonication reduced extraction time from 4 h (magnetic stirring method) to 1 h and increased three-fold the extraction recovery (from 21.5% to 66.6%). The concentrate had a 74.8 g/100 g DM protein content. The SDS-PAGE revealed protein degradation in some specimens, probably because of fermentation and enzymatic hydrolysis before sampling. However, the microbial counts in the concentrate, mainly related to lactic acid bacteria, were always below the guideline values. Our results demonstrate that the pea canning by-product is a valuable raw material for protein recovery and that the proposed method allows rapid and direct treatment, avoiding drying costs and microbial proliferation.

Challenges in Peptide Solubilization - Amyloids Case Study.

Peptide science has been a rapidly growing research field because of the enormous potential application of these biocompatible and bioactive molecules. However, many factors limit the widespread use of peptides in medicine, and low solubility is among the most common problems that hamper drug development in the early stages of research. Solubility is a crucial, albeit poorly understood, feature that determines peptide behavior. Several different solubility predictors have been proposed, and many strategies and protocols have been reported to dissolve peptides, but none of them is a one-size-fits-all method for solubilization of even the same peptide. In this review, we look for the reasons behind the difficulties in dissolving peptides, analyze the factors influencing peptide aggregation, conduct a critical analysis of solubilization strategies and protocols available in the literature, and give some tips on how to deal with the so-called difficult sequences. We focus on amyloids, which are particularly difficult to dissolve and handle such as amyloid beta (Aβ), insulin, and phenol-soluble modulins (PSMs).

Acrylamide macromolecules modified wine lees‐soy protein wood adhesive

AbstractTo expand the diverse applications of wine lees and enhance the adhesive properties of its protein‐based adhesive, the supernatant of wine lees, separated using the alkali solubilization method, was combined with a small quantity of soybean protein as the raw material. Cross‐linking modification was then conducted using polyacrylamide polymers to prepare the protein‐based adhesive. The results indicated that a total mass fraction of 2.5 wt% NaOH and 3.0 wt% urea effectively stretched the protein structure. Additionally, a mass ratio of 4:10 of trimethylolpropane triglycidyl ether and acrylamide, under the action of the ammonium persulfate initiator, resulted in effective cross‐linking of polyacrylamide macromolecules. The addition of 7 wt% polyacrylamide macromolecules as a cross‐linking agent effectively facilitated the cross‐linking reaction with wine lees‐soy protein. After the cross‐linking modification, the surface of the adhesive became tight and smooth. As a result, the water‐resistance strength of the plywood increased from 0.2 to 1.27 MPa, marking a 635% enhancement, which significantly surpassed the standard for Class II plywood (GB/T 9846‐2015).

Progress in Biomass Electro‐Valorization for Paired Electrosynthesis of Valuable Chemicals and Fuels

Environmental and energy concerns surrounding the use of fossil fuels are driving an increasingly rapid transition to sustainable and eco‐responsible processes. Electrochemical processes can provide the necessary sustainability and economic roadmap for storing intermittent and renewable electricity by synthesizing, in cogeneration electrolyzers, energy carriers and/or synthetic chemicals (hydrogen, ammonia, etc.) via flagship reduction reactions (hydrogen evolution reaction (HER), nitrogen reduction reaction (NRR), etc.). To balance the electrochemical process, these cathodic processes have long been coupled to the oxygen evolution reaction (OER), which ultimately consumes almost 90% of the energy input. Recent years have witnessed an overwhelming development of anode scenarios based on biomass substrates, because OER cannot be driven below a certain potential threshold, while organics are thermodynamically more favorable. Therefore, paired electrolysis, which refers to cases where electrochemical oxidation and reduction are desired, embraces the electrocatalysis community for the electrolytic production of hydrogen, ammonia, etc. (cathode side), in parallel with value‐added chemicals (anode side), all with a modest electricity input. The trade‐off is selectivity at relevant current densities. This review discusses, the progress, challenges, and potential of biomass‐fueled paired electrosynthesis of valuable chemicals and fuels. Fundamental principles, main biomass solubilization methods, and different scenarios for paired electrosynthesis are presented.

Theoretical and experimental study on the recovery of bromide by crystallization from pesticide production wastewater

Brominated wastewater from the propyl bromide pesticide production rich in ammonium, sodium and bromine salts at a high concentration of 11 %. For the recycling of chemical resources of this mixed brine salt system, this paper proposes a method for the separation of bromide from bromine-containing chemical wastewater by crystallization. According to the process design needs of the new method, and because 298 K and 323 K are two common temperatures in industrial practice, in this paper, the solubility data of the NaCl-NH4Cl-NaBr-NH4Br-H2O quaternary system at 298 K and 323 K, as well as its ternary subsystems, NaBr-NH4Br-H2O and NH4Cl-NH4Br-H2O at 323 K were determined by the isothermal solubilization method, and the corresponding phase diagrams were drawn. The solubility of the NaCl-NH4Cl-NaBr-NH4Br-H2O quaternary system at 298 K was also calculated using the Pitzer model, and the calculated results were in good agreement with the experimental measurements. Finally, based on the theoretical analysis of the phase diagrams of the 298 K and 323 K NaCl-NH4Cl-NaBr-NH4Br-H2O quaternary systems and combined with the phase diagrams of the 298 K NaBr-NaCl-CH3OH system, this paper proposes and designs a salt extraction process route for the brominated wastewater of the propyl bromide pesticide production. Through the separation experiment, the new process proved to be technically feasible and produced NaCl with 100 % purity, Na(Br,Cl) with 98.23 % NaBr, and NH4(Cl,Br) with 99.18 % and 97.57 % NH4Cl, respectively. The new process realizes the resourceful utilization of bromine-containing wastewater, and has the significant advantages of production safety and no emission of three wastes.

Development of a highly efficient solubilization method for mass spectrometric analysis of phospholipids in living single cells.

Phospholipids are vital constituents of the cell membrane and aid in signal transduction. Phospholipid profiles vary distinctively with the cell type. Notably, specific phospholipid molecules are present in significantly higher or lower concentrations in cancer cells versus normal cells. In this study, live single-cell mass spectrometry (MS) was developed for analyzing phospholipids at the single-cell level. This method facilitates rapid molecular analysis of cells under microscopic observation. For nanoelectrospray ionization, phospholipids were extracted from single cells isolated in a glass capillary through a high-efficiency process. Cell-derived phosphatidylcholines were detected with high sensitivity when trehalose C14 was added as a solubilizing reagent. Trehalose C14 can solubilize cells at low concentrations owing to its low critical micelle concentration, and exerts minimal matrix effects (such as suppressing ionization and causing peak overlap) in the MS analysis of cellular molecules. Analyses of phospholipids in Raji and HEV0070 cells using the developed method revealed specific peaks of phosphatidylcholine and sphingomyelin in the respective cells. The developed technique not only affords phospholipid profiles at the single-cell level, but also holds promise for identifying biomarkers associated with various diseases, particularly cancer.

Sample Preparation for Electron Cryo-Microscopy of Macromolecular Machines.

High-resolution structure determination by electron cryo-microscopy underwent a step change in recent years. This now allows study of challenging samples which previously were inaccessible for structure determination, including membrane proteins. These developments shift the focus in the field to the next bottlenecks which are high-quality sample preparations. While the amounts of sample required for cryo-EM are relatively small, sample quality is the key challenge. Sample quality is influenced by the stability of complexes which depends on buffer composition, inherent flexibility of the sample, and the method of solubilization from the membrane for membrane proteins. It further depends on the choice of sample support, grid pre-treatment and cryo-grid freezing protocol. Here, we discuss various widely applicable approaches to improve sample quality for structural analysis by cryo-EM.

The Characteristic Curvature (Cc) of Ionic Surfactants Assessed via Small-Angle X-ray Scattering.

The characteristic curvature (Cc), within the hydrophilic-lipophilic difference + net (Hn) - average (Ha) curvature (HLD-NAC) framework, is the dimensionless net curvature, -Hn·L (L is the surfactant's tail length parameter), that a surfactant acquires at the characteristic condition (T = 25 °C, no added cosurfactants, oil with an equivalent alkane carbon number (EACN) of zero and for ionic surfactants, a total salinity (S) of 1 g NaCl/100 mL). A recent article demonstrated the validity of the Cc concept, where Hn was assessed via oil and water solubilization radii. Here, we assess Hn from the characteristic length (ξ) obtained from the analysis of SAXS profiles of microemulsions produced at semicharacteristic conditions (characteristic condition but varying S). The predicted relationship, -L·Hn,semicharacteristic = Ccbi + bi·ln(S), was confirmed with the five ionic surfactants explored. The SAXS-assessed Cc (Cc = Ccbi/bi) values are consistent with those obtained from solubilization studies and phase inversion scans. The Cc-SAXS method provides a way to assess the hydrophobicity of ionic surfactants directly, avoiding the bias that could be introduced by cosurfactants in phase inversion studies and minimizing the impact of potential uncertainties in the surfactant volume to area ratio (vs/as) required to calculate the solubilization radii in the solubilization method.

Development and Validation of Simple UV Spectrophoto-metric Method for Estimation of Azithromycin in Dosage Form using Hydrotropic Solubilization Technique

Objective: A new UV method was developed for the estimation of azithromycin in tablets using the hydrotropic solubilization method and it was validated as per ICH guidelines. Methods: The solubility of azithromycin was studied in various hydrotropic agents and the one with the best solubility was considered as solvent for developing and validating the UV spectrophotometric method. Results: The best solubility of azithromycin was witnessed in a 2M sodium acetate solution in water. The absorption maximum of azithromycin in 2M sodium acetate was found to be 221 nm. The method was found to be linear in the range of 10-50µg/ml. The precision of the method was good and the recovery of drugs was well within the acceptance limits of 80-120%. Conclusion: The proposed UV method was found suitable for the estimation of azithromycin in formulations and is simple, selective, reproducible, and accurate with good precision, and can be successfully applied to routine analytical purposes.

Natural biomass-derived carbon dots as a potent solubilizer with high biocompatibility and enhanced antioxidant activity.

Numerous natural compounds exhibit low bioavailability due to suboptimal water solubility. The solubilization methods of the modern pharmaceutical industry in contemporary pharmaceutical research are restricted by low efficiency, sophisticated technological requirements, and latent adverse effects. There is a pressing need to elucidate and implement a novel solubilizer to ameliorate these challenges. This study identified natural biomass-derived carbon dots as a promising candidate. We report on natural fluorescent carbon dots derived from Aurantia Fructus Immatures (AFI-CDs), which have exhibited a remarkable solubilization effect, augmenting naringin (NA) solubility by a factor of 216.72. Subsequent analyses suggest that the solubilization mechanism is potentially contingent upon the oration of a nanostructured complex (NA-AFI-CDs) between AFI-CDs and NA, mediated by intermolecular non-covalent bonds. Concomitantly, the synthesized NA-AFI-CDs demonstrated high biocompatibility, exceptional stability, and dispersion. In addition, NA-AFI-CDs manifested superior free radical scavenging capacity. This research contributes foundational insights into the solubilization mechanism of naringin-utilizing AFI-CDs and proffers a novel strategy that circumvents the challenges associated with the low aqueous solubility of water-insoluble drugs in the field of modern pharmaceutical science.

Determination Of Some Trace Elements In Some Lipstick Products By Inductive Coupled Plasma-Mass Spectrometry

Cosmetics have been attracting the attention of humanity since it existed. Over the years, the reach of the cosmetics industry has increased exponentially. In recent years, cosmetic manufacturers have developed many formulations on cosmetic products that are brighter in color, more permanent and not easily affected by external factors. However, heavy metal powders are used while producing these formulations especially inside in dyestuffs and stabilizers. Cosmetic products can be absorbed through the skin and cause systemic toxicity. Hundreds of chemicals are used in many cosmetic products such as make-up products, shampoos, creams, aftershaves, and these chemicals may cause significant health problems. Thus, this study is designed to investigate the heavy metal content of lipstick samples which are used extensively by women. Determination of aluminum (Al), chromium (Cr), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), elements in 35 different lipstick samples (including 15 brands) were performed by Inductively Coupled Plasma-Mass Spectrophotometer (ICP-MS) device. Before the analysis, two different solubilization methods, wet solubilization and dry ashing, were applied to the samples in order to take the metals in the lipstick samples into inorganic environment

An Ecofriendly Novel Spectrophotometric Estimation and Validation of Meloxicam in Bulk Drug and their Dosage Form by mixed Hydrotropic Solubilization Method

Solubility is a crucial factor during estimation of poorly soluble drugs. Literature survey reveals spectrophotometric estimation of poorly soluble drugs are mostly done by employing organic solvents. The drawbacks of organic solvents include higher cost, toxicity, pollution and error due to volatility. Hydrotropic solubilisation method involves increasing the solubility of a poorly soluble drug in water with the addition of hydrotropic agents. Most of NSAIDs like Meloxicam, Mefenamic acid, Aceclofenacetc are poorly soluble in water. Meloxicam was found to be soluble in mixed hydrotropic solution of 10% sodium benzoate and 10% sodium caprylate with maximum absorbance at 364 nm. The developed method was found to be linear in the range of 2-10 µg/ml with correlation coefficient (R2) of 0.9968. The LOD and LOQ of proposed method was found to be 0.2634 µg/ml and 0.7983 µg/ml respectively. A novel, simple, safe, sensitive and cost-effective spectrophotometric estimation method was developed for estimation of Meloxicam using 10% sodium benzoate and 10% sodium caprylate as hydrotropic agent. This solubilization method can be employed to preclude the use of organic solvents for the estimation of poorly soluble drugs.

Solubilization of Poorly Water-soluble Drugs with Amphiphilic Phospholipid Polymers

Most drug candidates developed in recent years are poorly water-soluble, which is a key challenge in pharmaceutical science. Various solubilization methods have been investigated thus far, most of which require solubilizers that provide a local hydrophobic environment wherein a drug can dissolve or induce interactions with drug molecules. We have focused on amphiphilic 2-methacryloyloxyethyl phosphoryl choline (MPC) polymers. In addition to the ease of molecular design of amphiphilic MPC polymers owing to their chemical structures, they have been reported to possess high biocompatibility in various biomaterial applications. Additionally, amphiphilic MPC polymers have been applied in the pharmaceutical field, especially in solubilization. We have qualitatively and quantitatively evaluated the effects of the chemical structure and physical properties of the solubilizer on the MPC polymers. In particular, MPC polymers with different chemical structures were designed and synthesized. The inner polarity and molecular mobility in the polymer aggregates were evaluated, indicating that the intrinsic properties reflect the chemical structure of the polymer. Additionally, amphiphilic MPC polymers were used to improve the solubility of poorly water-soluble drugs and as solid dispersion carriers, and they exhibited superior solubilizing abilities compared to a commonly used polymer. Furthermore, the solubility of biopharmaceuticals, such as peptides, was improved. It is possible to design and synthesize optimal structures based on the polarity of the hydrophobic environment and the intermolecular interaction with a drug. This research provides a unified interpretation of drugs and efficiently summarizes knowledge about drug development, which will facilitate the efficient and rapid development of drug formulations.

Performance of fish sludge solubilization and phototrophic bioconversion by purple phototrophic bacteria for nutrient recovery in aquaponic system

Nutrient recovery from fish sludge in aquaponics is crucial to improve the economic output of a system sustainably and hygienically. Currently, fish sludge is treated using conventional anaerobic and aerobic mineralization, which does not allow the recovery of valuable nutrients in fish wastes. In this study, a two-stage approach (named as solubilization process and phototrophic bioconversion) is proposed to convert fish sludge into mineral nutrients and biomass nutrients using purple phototrophic bacteria (PPB), thereby promoting the growth of plants and fish simultaneously in aquaponics. Anaerobic and aerobic solubilization methods are tested to pretreat the fish sludge, generating substrates for PPB. Anaerobic solubilization yields 2.1 times more soluble chemical oxygen demand (SCOD) and 3.7 times more total volatile fatty acid (t-VFA) from fish sludge compared with aerobic solubilization. The anaerobic solubilization effluent indicates a CODt-VFA/SCOD of 60% and a VFA comprising 13.3% acetate and 49.0% propionate for PPB. The phototrophic bioconversion using anaerobic solubilization effluent under the light-anaerobic condition results in the highest biomass yield (0.94 g CODbiomass/g CODremoved) and the highest PPB dominance (Ectothiorhodospira, 58.7%). The anaerobic solubilization and light-anaerobic phototrophic bioconversion achieves 54.1% of carbon recovery efficiency (CRE) (in terms of COD), as well as 44.8% and 91.3% of nutrient recovery efficiency (NRE) for N and P. A novel multiloop aquaponic system combined with PPB-based nutrient recovery is proposed for the reuse of mineral nutrients and PPB biomass generated from fish sludge.

Enhanced production and single step purification of biologically active recombinant anti-IL6 scFv from Escherichia coli inclusion bodies

Interleukin 6 (IL-6) is a proinflammatory cytokine that plays a critical role in immune responses and inflammation. Overexpression of IL-6 serves as a biomarker for various diseases. Therefore, it is vital to develop IL-6-specific antibodies for the diagnosis and treatment of inflammatory diseases. Alternatively, high-yield production of single-chain variable fragments (scFv) in prokaryotes reduces the time and cost required while attaining a similar specificity. However, overexpression of eukaryotic proteins in bacterial expression systems often leads to the formation of inclusion bodies. Here, a codon-optimized anti-IL6 scFv was expressed in the E. coli SHuffle strain, and the effects of inclusion body solubilisation methods on the product yield were investigated. A high concentration (23 mg/L) of biologically active and pure (>95 %) scFv was obtained without any need for a refolding step following solubilisation with a non-denaturing solubilisation agent, N-lauroyl sarcosine. Activity assays showed that anti-IL6 scFv could specifically bind to its antigen. Overall, we present reproducible and efficient production of anti-IL6 scFv in E. coli by using a one-step purification method. While the biologically active and pure antibody fragment can be used for diagnostic studies of the IL-6 cytokine, the developed method can be applied to other recombinant proteins expressed in E. coli.

Structural Properties of Quinoa Protein Isolate: Impact of Neutral to High Alkaline Extraction pH.

In this work, we extracted proteins from white quinoa cultivated in the northeast of Qinghai-Tibet plateau using the method of alkaline solubilization and acid precipitation, aiming to decipher how extraction pH (7-11) influenced extractability, purity and recovery rate, composition, multi-length scale structure, and gelling properties of quinoa protein isolate (QPI). The results showed that protein extractability increased from 39 to 58% with the increment of pH from 7 to 11 whereas protein purity decreased from 89 to 82%. At pH 7-11, extraction suspensions and QPI showed the similar major bands in SDS-PAGE with more minor ones (e.g., protein fractions at > 55 or 25-37 kDa) in suspensions. Extraction pH had limited effect on the secondary structure of QPI. In contrast, the higher-order structures of QPI were significantly affected, e.g., (1) emission maximum wavelength of intrinsic fluorescence increased with extraction pH; (2) surface hydrophobicity and the absolute value of zeta-potential increased with increasing extraction pH from 7 to 9, and then markedly decreased; (3) the particle size decreased to the lowest value at pH 9 and then increased to the highest value at pH 11; and (4) denaturation temperature of QPI had a large decrease with increasing extraction pH from 7/8 to 9/10. Besides, heat-set QPI gels were formed by loosely-connected protein aggregates, which were strengthened with increasing extraction pH. This study would provide fundamental data for industrial production of quinoa protein with desired quality.

Xylan Solubilization from Partially Delignified Biomass, and Residual Lignin Removal from Solubilized Xylan

Xylan is a macromolecule of industrial interest that can be solubilized from lignocellulosic materials, such as sugarcane bagasse, which is a renewable source. However, the solubilization methods of xylan need to be better developed for use in industrial applications. The main objective of this study was to evaluate xylan solubilization methods with higher yields and purity by using biomasses/fractions of sugarcane: leaf and stem, internode, node, and external fraction. Two strategies were evaluated by applying diluted sodium chlorite, sodium sulfite, and hydrogen peroxide: a delignification of the biomass before xylan solubilization; and the delignification of the solubilized xylan for residual lignin removal. The delignification of the biomass before the xylan solubilization enabled to identify material and specific conditions for yields higher than 90%. Residual lignin varied from 3.14 to 18.06%, with hydrogen peroxide in alkaline medium partial delignification shown to be effective. The delignification of xylan presented better results using diluted hydrogen peroxide, with a reduction of 58.44% of the initial lignin content. The solubilized xylans were used as a substrate for xylanase activities, resulting in higher activity than commercial xylan. In the delignification of the biomasses, hydrogen peroxide was the reagent with better results concerning the yield, purity, and solubility of the xylan. This reagent (diluted) was also better in the delignification of the solubilized xylan, resulting in lower residual lignin content. The solubility and purity tests (low salt content) indicated that the solubilized xylan presented characteristics that were similar to or even better than commercial xylan.

Functional modification of mussel adhesive protein to control solubility and adhesion property

Marine mussels produce strong underwater adhesives called mussel adhesive proteins (MAPs) that can adhere to a variety of surfaces under physiological conditions. Thus, MAPs have been investigated as a potentially sustainable alternative to conventional petrochemical-based adhesives. Recombinant MAPs would be promising for large-scale production and commercialization; however, MAPs are intrinsically adhesive, aggregative, and insoluble in water. In this study, we have developed a solubilization method for the control of MAP adhesion by fusion protein technique. Foot protein 1 (Fp1), a kind of MAP, was fused with the highly water-soluble protein, which is the C-terminal domain of ice-nucleation protein K (InaKC), separated by a protease cleaving site. The fusion protein exhibited low adhesion but high solubility and stability. Notably, Fp1 recovered its adhesive property after removal from the InaKC moiety by protease cleaving, which was evaluated and confirmed by the agglomeration of magnetite particles in water. The ability to control adhesion and agglomeration makes MAPs favorable prospects for bio-based adhesives.

Thermal hydrolysis of sewage sludge: Improvement in biogas generation and prediction of global warming potential.

Anaerobic digestion (AD) is a prominent treatment method for the sludge produced from sewage treatment plants. Poor solid reduction and longer retention time are the main drawbacks of AD. Thermal hydrolysis (TH) is a potential pretreatment method for solubilization of sewage sludge (SS) solids thereby improving biogas production during AD post-treatment. In this study, the SS sample (total solids = 1.75 wt% and total chemical oxygen demand (COD) = 15,450 mg L-1) was subjected to TH pretreatment (temperature = 140-180°C and reaction time = 60 minutes) in a 0.7-L capacity stainless-steel high-pressure reactor. At a reaction temperature of 180°C, the maximum solid solubilization (total dissolved solids = 4652 mg L-1) and improved dewaterability (time to filter = 4.7 s.L g-1) were observed. The biochemical methane potential test results showed almost doubling of methane generation from 145 to 284 mL gCOD-1 after TH pretreatment at 180°C. The life cycle assessment approach was used to compare various SS treatment and disposal scenarios, two of which included hydrothermal pretreatment. The scenarios involving hydrothermal pretreatments showed the least global warming potential.