Parameters For Hydrolysis Research Articles

P-1370. Molecular Bases and Mechanistic Insights of NDM-mediated Resistance to Cefiderocol

Abstract Background Cefiderocol (FDC) is a novel cephalosporin with a siderophore-mimicking moiety that favors uptake into the periplasm through iron transporters. FDC was reported as the only cephalosporin refractory to hydrolysis by metallo-β-Lactamases (MBLs). However, resistance to FDC has been reported due to substitutions in the iron transporter coupled to the expression of the MBLs NDM-1 and NDM-5. In contrast, resistance emergence involving other MBLs such as VIM or IMP are not known. We aimed to identify the interaction of FDC with NDM and other MBLs.Table 1.Kinetic parameters of FDC hydrolysis by different MBLsNDM variants show considerable activity in FDC hydrolysis. In contrast, VIM-2 and IMP-1 show poor activity. Methods MICs values of FDC against Escherichia coli DH10B cells expressing different MBLs cloned into a pHSG298 vector were determined by the microdilution method in iron-depleted cation-adjusted Mueller-Hinton broth. NDM-1, NDM-5, IMP-1 and VIM-2 were expressed in E. coli BL21(DE3) pLysS and purified by affinity chromatography. Steady state catalytic parameters were determined by initial rate measurements measured in HEPES buffer, pH 7.5 at 25°C. NMR spectra were run in a 700 MHz Bruker spectrometer. Stopped-flow data were acquired in an Applied Photophysics spectrophotometer. Mechanism of MBL-mediated resistance to FDC Under high levels of NDM expression, the enzymatic activity counter the cefiderocol action, confering bacterial resistance against this antibiotic. Results MIC values of FDC in E. coli cells expressing NDM variants were 2 μg/ml, similar to NDM-1. Steady-state kinetic measurements showed that NDM-1 and NDM-5 hydrolyze FDC efficiently, with kcat/KM values of 1.9 and 1.2 x10^6 M-1s-1, respectively. In contrast, IMP-1 and VIM-2 displayed poor catalytic efficiencies (Table 1). Electrospray ionization mass spectrometry (ESI-MS) revealed that FDC forms an adduct with MBLs, which is significantly more stable in the case of IMP-1 and VIM-2. Stopped flow experiments under pre-steady state conditions show that both IMP-1 and VIM-2 form a stable adduct with FDC, that results in enzyme inhibition. Instead, NDM-1 is poorly inhibited since the formed adduct is less stable. NMR experiments confirmed the formation of an hydrolysis product and adduct. Conclusion Our results indicate that NDM-1 and NDM-5 hydrolyze FDC efficiently, in contrast to the poor activity of IMP-1 and VIM-2. These findings support the observation that clinical resistance is linked to overexpression of NDM variants and not to IMP-1 and VIM-2. This may guide the use of FDC against a specific group of MBLs and justifies pairing with an MBL inhibitor. Disclosures All Authors: No reported disclosures

Spatial Scale Matters: Hydrolysis of Aryl Methyl Ethers over Zeolites.

The local environment of the active site, such as the confinement of hydronium ions within zeolite pores, significantly influences catalytic turnover, similar to enzyme functionality. This study explores these effects in the hydrolysis of guaiacols─lignin-derived compounds─over zeolites in water. In addition to the interesting catechol products, this reaction is advantageous for study due to its bimolecular hydrolysis pathway, which involves a single energy barrier and no intermediates, simplifying kinetic studies and result interpretation. As in alcohol dehydration, hydronium ions show enhanced activity in ether hydrolysis due to undercoordination and increased electrophilicity when confined within zeolite pores, compared to bulk water. In addition, a volcano-shaped relationship between hydronium ion activity and Brønsted acid density was observed. However, unlike alcohol dehydration, this activity distribution cannot be attributed to variations in ionic strength within the pores, as the rate-determining step in the hydrolysis of guaiacols involves the attack of a neutral water molecule, unaffected by ionic strength. Instead, a detailed transition state analysis revealed a significant thermodynamic energy compensation effect, driven by the spatial organization of the transition state. This organization is influenced by the available reaction space, the interaction between the reacting species and the zeolite environment, leading to the volcano-shaped dependence. This phenomenon also explains the unusual reactivity order of the 4-R-guaiacol derivatives (R = H, Me, Et, Pr) with zeolite catalysis, extending beyond the traditional steric and electronic effects to provide a deeper understanding of reactant reactivity. The work concludes that the critical spatial parameters for fast ether hydrolysis─resulting in the highest hydronium activity─are determined by a combination of zeolite properties (topology and acid density) and reactant size.

Nanocellulose extraction from date palm waste using 1-butyl-3-methylimidazolium hydrogen sulphate.

This study provides insights into nanocellulose production using 1-butyl-3-methylimidazolium hydrogen sulphate ([Bmim]HSO4) as a green solvent, utilizing cellulose derived from date palm waste. Critical hydrolysis parameters were optimized through analysis of variance and response surface methodology. The predicted nanocellulose yield (Y) followed a quadric equation represented by Y=55.48-0.57pH-0.478ST+0.997T-0.006721T2+0.0681pH×ST-0.0681pH×T+0.003833ST×T. The developed empirical model showed excellent predictive accuracy (R2>0.95). The optimized hydrolysis parameters were pH1, a temperature of 80°C, and a stirring time of 45min, resulting in an 80.5% yield of nanocellulose. Scanning electron microscopy showed the nanocellulose's needle like morphology, while transmission electron microscopy indicated an average particle size ranging from 50 to 60nm. Fourier transform infrared spectroscopy confirmed the purity of the nanocellulose by indicating the removal of non-cellulosic components. X-ray diffraction analysis showed a crystallinity index (Crl) of 72.22%, representing a 67.5% increase compared to the Crl raw date waste. Dynamic light scattering showed a hydrodynamic diameter of approximately 100nm. Thermal stability performed using thermogravimetric analysis indicated a high initial degradation temperature (Tonset) of 233°C, while differential scanning calorimetry confirmed the absence of melting transitions up to 250°C, underscoring the material's exceptional thermal stability. This study highlights the robust capability of [Bmim]HSO4 to produce high quality nanocellulose from lignocellulose-derived cellulose, broadening its application beyond the previously reported use with microcrystalline cellulose to produce nanocellulose.

Structural Feature of Salty/Saltiness-Enhancing Peptides Derived from Coprinus comatus and Their Stability during Subsequent Thermal Treatment and Maillard Reaction.

Through a quantitative analysis of saltiness perception, favorable enzymatic hydrolysis parameters were confirmed for the preparation of saltiness-enhancing peptide mixtures from Coprinus comatus. The enzymatic hydrolysate was fractionated into four fractions (F1-F4) by gel chromatography, with F3 exhibiting the strongest saltiness-enhancing effect (22% increase). LC-MS/MS analysis of F3 identified 36 peptides, and their secondary structures and interactions with the TMC4 receptor were examined through circular dichroism spectroscopy and molecular docking. Molecular docking analysis revealed Asn588, Ser165, Asp5, and Arg168 as key amino acid residues, with the peptide GDNVGF showing the lowest binding energy. Synthetic GDNVGF (0.01%) in 70 mmol/L NaCl enhanced saltiness by 17%. When 0.7% GDNVGF was added to the aqueous solution, its saltiness was equivalent to that of 36.89 mmol/L NaCl, which suggested that GDNVGF functions both as a saltiness-enhancing peptide and a salty peptide. The taste changes of peptides during thermal reactions were further investigated. The thermal stability of Coprinus comatus peptides was good, but their saltiness-enhancing effect slightly reduced due to thermal degradation. The Maillard reaction further diminished this effect, though the umami level remained satisfactory, offering new insights into using Coprinus comatus peptides as low-sodium salt substitutes.

Preparation of nitrogen liquid fertiliser derived from sheep wool

ABSTRACT This work focuses on the synthesis of a liquid fertiliser deriving from sheep wool waste.. Nitrogen-rich sheep’s wool underwent alkaline hydrolysis with potassium hydroxide. The product obtained by an alkaline hydrolysis process contains nitrogen, phosphorus and potassium, which are the main nutrients necessary for plant growth The hydrolysis parameters, temperature, reaction time, and alkaline agent concentration were optimized using response surface methodology and Box-Behnken design. The amino acids and oligo-elements content of the resulting product also appear to have a positive effect combined with the nutrients when applied to the agricultural field. An adding phosphoric acid to incorporate phosphorus and reduce pH was made, addressing potential stress from alkaline conditions, especially in Moroccan soils. A stability study at pH levels (5, 6, 7, 8) over 120 hours and at temperatures (17°C and 25°C) indicated that neutralization at acidic pH leads to phosphorus potassium salts formation. This new fertilizer is designed for agronomic application.

Changes in the Composition, Antioxidant Activity, and Sensory Attributes of Olive Oil Used as a Storage Medium for Dried Tomato Preservation.

The presence of food in extra virgin olive oil (EVOO) during simultaneous storage might bring additional changes to the oil's composition and quality. To investigate this matter, the influence of dried tomatoes on the oxidative and hydrolytic parameters, fatty acids, phenolic and volatile composition, antioxidant activity, pigments, and sensory attributes of EVOO during six months of simultaneous storage at room temperature (RT; 22 ± 2 °C) and +4 °C, was studied. Lower storage temperature reduced the hydrolytic and oxidative degradation of oils when dried tomatoes were immersed. The dried tomatoes addition did not affect the fatty acids composition of EVOO. The accelerated degradation kinetics of individual phenolic compounds and antioxidant activity of oils were influenced by the presence of dried tomatoes, being more pronounced at RT. C6 and C5 volatiles responsible for the green odour of EVOO decreased, while tomato-derived volatiles (3-methylbutanal and acetic acid) increased during simultaneous storage with dried tomatoes, especially at RT. The addition of dried tomatoes diminished the intensities of EVOO's positive attributes (fruitiness, bitterness, and pungency) while enhancing the tomato odour attribute. This study demonstrates that the introduction of dried tomatoes significantly alters the composition and quality of EVOO when used as a storage medium.

Nanocrystalline cellulose from Calophyllum inophyllum shells waste by adjusting organic acid hydrolysis and optimization of reaction parameters using response surface methodology

Biodiesel production from Calophyllum inophyllum oil in Indonesia produces significant biomass waste, including seed shells. This study explores the conversion of the seed shell of Calophyllum inophyllum into nanocrystalline cellulose (NCC) via consecutive alkalization, bleaching and hydrolysis using various organic acids. Scanning electron microscopy (SEM) analysis showed a reduction in the diameter of cellulose fibers from 21.7 μm to 9.6 μm after alkalinization and bleaching. The hydrolysis process using several organic acids was optimized to produce thermally stable nanocellulose while maintaining its crystallinity. The diameter of the resulting nanofibrous cellulose was 20.53 nm for citric acid, 21.69 nm for maleic acid, and 22.06 nm for formic acid hydrolysis. In particular, lactic acid-derived NCC (NCC-LA) showed the highest crystallinity of 64.22 % with an average diameter of ~13.69 nm. Optimization of hydrolysis parameters using Response Surface Methodology (RSM) suggested 74.79 % crystallinity could be achieved with 6.01 M lactic acid following 3.46 h of hydrolysis at 91.12 °C.

Direct Preparation of Alginate Oligosaccharides from Brown Algae by an Algae-Decomposing Alginate Lyase AlyP18 from the Marine Bacterium Pseudoalteromonas agarivorans A3.

Alginate oligosaccharides (AOs), derived from alginate degradation, exhibit diverse biological activities and hold significant promise in various fields. The enzymatic preparation of AOs relies on alginate lyases, which offers distinct advantages. In contrast to the conventional use of sodium alginate derived from brown algae as the substrate for the enzymatic preparation of AOs, AO preparation directly from brown algae is more appealing due to its time and energy efficiency. Thus, the identification of potent alginate lyases and cost-effective brown algae substrates is crucial for optimizing AO production. Herein, we identified and characterized an alginate lyase, AlyP18, capable of efficiently decomposing algae, from a marine bacterium Pseudoalteromonas agarivorans A3 based on secretome analysis. AlyP18 is a mesothermal, endo-type and bifunctional alginate lyase with high enzymatic activity. Two brown algae substrates, Laminaria japonica roots and Macrocystis pyrifera, were used for the AO preparation by AlyP18. Upon optimization of AlyP18 hydrolysis parameters, the substrate degradation efficiency and AO production reached 53% and ~32% for L. japonica roots, respectively, and 77% and ~46.5% for M. pyrifera. The generated AOs primarily consisted of dimers to pentamers, with trimers and tetramers being dominant. This study provides an efficient alginate lyase and alternative brown algal feedstock for the bioconversion of high-value AOs from brown algae.

Бифидогенная кормовая добавка на основе вторичного молочного и растительного сырья

Gastrointestinal infectious diseases accompany the growth of animal and poultry farming: as the livestock population increases, its high concentration on farms raises the level of mortality and rejection, thus reducing the overall safety and productivity. Probiotics and prebiotics used as feed additives may be an effective preventive measure. The article describes a sustainable and environmentally friendly method for obtaining prebiotics of pectin oligosaccharides by hydrolyzing apple pomace pectin in whey with Saccharomyces cerevisiae to produce bifidogenic animal feed. The 5:1 ratio of whey and apple pomace increased the yeast biomass by 56.3% after 24 h of fermentation and introducing 0.3% yeast by weight. The pectin hydrolysis products triggered an intensive growth of the substrate. The hydrolysis products contained 32% oligosaccharides of average molecular weight. The enzymatic hydrolysis of whey-apple mixes with a β-galactosidase preparation by deep cultivation of Bacillus licheniformis prevented the negative effect of serum lactose consumption, as well as increased the yield of yeast biomass. The optimal hydrolysis parameters were pH 6.0, 25 °C, 0.04% enzyme, and 6 h. The technological process included the following stages. The raw materials were prepared as a whey-vegetable mix (5:1), which was gradually heated to 65 °C. After cooling down to 22-25 °C, dry Saccharomyces cerevisiae provided fermentation and deoxidation. After introducing lactase enzyme and final thermal treatment, the finished feed additive contained 10% solids, 3.5% nitrogenous substances, 0.6% pectin, 0.3% pectin oligosaccharides, and 0.2% residual lactose, as well as vitamins and minerals.

Using an ensemble Kalman filter method for a soil nitrogen transport model in the real rice field

The overuse of nitrogen fertilizer in rice field of China leads to nitrogen loss and serious water pollution, so it is vital to accurately predict soil nitrogen transport in rice field. But the prediction errors of soil nitrogen transport are great due to complex chemical and reactive conditions and uncertain parameters in real rice fields. In this study, a prediction model of soil nitrogen transport in a rice field was established via modifying the HYDRUS-1D source code, and a data assimilation method called the ensemble Kalman filtering (EnKF) was coupled, based on the observed NH4+-N and NO3–-N concentrations at different depths in a real rice field. Study results for two different protocols of assimilating observed NH4+-N and NO3–-N concentrations simultaneously and separately were compared. It indicated the predictions accuracy of NH4+-N and NO3–-N concentrations was improved significantly via the EnKF method, and the former protocol is better than the latter. Moreover, for the latter protocol, observations of NO3–-N concentrations were more efficient than NH4+-N to improve the predictions accuracy of NH4+-N and NO3–-N concentrations at different depths. Inversed parameters of urea hydrolysis, NH4+-N volatilization, soil adsorption of NH4+-N, nitrification and denitrification increased over time. On the whole, the inversed model parameters were more stable at deep soil than shallow soil, which were different at different depths. With soil depths increase, parameters of the NH4+-N adsorption and NO3–-N denitrification increased, while parameters of urea hydrolysis, NH4+-N volatilization and nitrification decreased. This study improved the model predictions accuracy and inversed the model parameters, revealing the mechanism of nitrogen loss in real rice fields, which can provide scientific basis to reduce serious environmental problems caused by the overuse of nitrogen fertilizer.

The use of protein hydrolysate from fish waste as part of microbiological culture media

The need to involve in the processing of significant amount of secondary protein-containing raw materials formed during fish cutting, on the one hand, and on the other hand, the shortage of a source of the protein component of microbiological nutrient media determines the relevance of the work. The goal was to study the possibility of using fish protein hydrolyzate obtained by enzymatic hydrolysis from secondary fish raw materials in microbiological nutrient media. Microbiological and physicochemical methods were used to conduct research. When optimizing the developed algorithm for the fermentation process, a mathematical model of the experiment was used with a minimum number of experiments. An algorithm has been developed for obtaining fish protein hydrolyzate from meat and bone waste from cutting pelagic fish (cod). The hydrolysis parameters were optimized: the concentration of the enzyme preparation is 1.33 % of the total mass of waste, the duration of the fermentation process – 3 hours. The characteristics of the resulting fish hydrolyzate are determined: the mass fraction of total nitrogen – 13 %, amine – 3.6 %, water – 4.6 %, sodium chloride – 2.7 %, fat – 0.3 %. An experimental fish hydrolyzate has been studied as a source of protein nitrogen in accordance with the formulation of a microbiological medium used for counting when growing colonies of microorganisms. The effectiveness of the prepared nutrient media was assessed by comparing the performance coefficients of the experimental and control nutrient media, as well as by identifying test microorganisms grown on the experimental medium. It was established that the growth pattern of test cultures both on the studied nutrient medium and on the control medium was almost the same. Test microorganisms retained their biochemical, morphological and cultural characteristics. The research results showed the possibility of using fish protein hydrolyzate obtained by enzymatic hydrolysis from secondary fish raw materials in microbiological nutrient media.

Production, Characterization, Kinetics, and Thermodynamics Analysis of Amyloglucosidase from Fungal Consortium.

The current study aimed to produce an amyloglucosidase enzyme from the fungal consortium. The best amylolytic fungal consortia were identified as Alternaria alternata and Aspergillus niger through the 18S rDNA technique. Fermentation kinetics and various nutritional and cultural parameters were analyzed. Maximum production was obtained in M4 media, pH 5.5, 30°C, and 4mL inoculum at 150rpm after 72h of incubation. Along with that, sodium nitrate at 2.5%, maltose, beef extract 1%, zinc sulfate (0.1%), and Tween 80 (0.1%) supported the maximum amyloglucosidase production. Amyloglucosidase was partially purified up to 1.6 purification fold with a specific activity of 1.84 Umg-1 in a stepwise manner by ammonium sulfate purification, dialysis, and ion exchange chromatography. The AMG enzyme also revealed maximum activity at 50°C with 5.0 pH. Upon the kinetic analysis, the specific yield coefficient Yp/x and volumetric rates Qp and Qx were also found to be significant in the above optimized conditions. The Km value 0.33mgmL-1 and Vmax 26.31 U mL-1 were obtained at 1% soluble starch substrate. Thermodynamic parameters for soluble starch hydrolysis were as follows: ΔH = 48.78kJmol-1, (Ea) = - 46.0kJmol-1, and ΔS = - 43.10Jmol-1K-1. This finding indicates the indigenously isolated fungal consortium can be the best candidate for industrial applications.

Ultrasound-assisted hydrolysis of food waste using glucoamylase: Statistical optimization and mechanistic analysis with molecular simulations

This paper reports investigations in food waste hydrolysis using ternary approach that combines statistical optimization, ultrasound-assisted enhancement of hydrolysis kinetics, and molecular simulations that provide physical insight into the process. Initial optimization of hydrolysis parameters (Box–Behnken design) resulted in total reducing sugar yield of 263.4 mg/g biomass in 42 h. Sonication of hydrolysis mixture at 35 kHz at 20 % duty cycle yielded 4× reduction in hydrolysis time with 22 % enhancement in TRS yield (320 mg/g biomass). Analysis of GLCM's secondary structure through FTIR spectra deconvolution revealed significant changes induced by sonication. Sonication led to reduction in α-helix, and increase in random coil content. Molecular dynamics simulations unveiled majority of amino acid residues associated with GLCM binding pocket in α-helix and random coil regions. Consequently, sonication widened the binding pockets, facilitating easier transport of substrate and product. This effect translated into faster kinetics of enzymatic food waste hydrolysis.

A review on textile solid waste management: Disposal and recycling.

Due to global population growth and living standards improvements, textile production and consumption are increased. Textile solid waste has become challenging issue for waste management authority. It is reported that textile materials are discarded daily, representing approximately 1.5% of the generated waste around the world. Over the past few decades, special attention has been given to the used clothes in all regions globally, which can reduce energy costs by 80% and also represent a source of raw materials economically profitable and environmentally responsible. This review article attempted to address different topics including: source of solid textile waste, environmental impact of textile waste as a result of massive consumption of clothing, textile waste management processes such as recycling, reuse of textile waste, landfill and incineration and energy recovery from textile waste. Narrative review with collection of recent quantitative information was carried to reflect the status of textile solid waste. In this article, the possibilities of bio-ethanol production from textile waste as valuable cellulosic raw material are investigated and presented. Results show that developing countries lack of systematic waste management. On another side of the globe, some countries are trying to recover energy these days by incineration. The heat and power that recovered from this process can be used instead of other energy sources. Throughout the incineration process, flue gases (CO2, H2O, O2, N2) are generated so it should be properly designed to avoid pollution. During energy recovery, different pre-treatment methods and different enzymatic hydrolysis parameters are recommended to be implied for better results.

Low-Molecular-Weight Peptides Prepared from Hypsizygus marmoreus Exhibit Strong Antioxidant and Antibacterial Activities.

Hypsizygus marmoreus has abundant proteins and is a potential source for the development of bioactive peptides. However, currently, the research on the bioactive components of H. marmoreus mainly focuses on polysaccharides, and there is no relevant research on the preparation of bioactive peptides. In this article, an ultrasound-assisted extraction method was used to extract proteins from H. marmoreus, and then, four peptides with different molecular weight ranges were prepared through protease hydrolysis and molecular classification. The antioxidant and antibacterial activities were also studied. Under the optimal conditions, the extraction rate of H. marmoreus proteins was 53.6%. Trypsin exhibited the highest hydrolysis rate of H. marmoreus proteins. The optimal parameters for enzymatic hydrolysis were a substrate concentration of 3.7%, enzyme addition of 5700 U/g, pH value of 7, extraction temperature of 55 °C, and time of 3.3 h. Under these conditions, the peptide yield was 59.7%. The four types of H. marmoreus peptides were prepared by molecular weight grading. Among them, peptides with low molecular weight (<1 kDa) had stronger antioxidant and antibacterial activities. This study provides a theoretical basis for the efficient preparation of H. marmoreus peptides and the development of antioxidant and antibacterial peptide products.

An optimize adaptable method for determining the monosaccharide composition of pectic polysaccharides

Pectic polysaccharides are considered the highly complex natural plant polysaccharides which plays a vital role in plant tissue structure and human health. Detailed characterization of the monosaccharide composition can provide insights into the pectic polysaccharide structure. Nevertheless, when analyzing the monosaccharides of pectic polysaccharide, it is crucial to address the issue of incomplete hydrolysis that can occur due to the formation of acid-induced precipitates. Based on above, the main purpose of this article is to provide an optimized method for monosaccharide analysis of pectic polysaccharides through acid hydrolysis optimization using high-performance anion exchange chromatography (HPAEC) The results indicate that reducing the sample concentration to 0.5 mg/mL effectively reduces the acid gelling phenomenon and promotes the complete hydrolysis of pectin polysaccharides. The optimized parameters for acid hydrolysis involve 110 °C for 6 h in 2 M TFA. Furthermore, the consistency of this method is assessed, along with its ability to analyze pectin polysaccharides from various fruits. This hydrolysis approach holds promise for enabling accurate quantification of monosaccharide composition in pectic polysaccharides.

Process Parameter Optimization of Waste Polyethylene Terephthalate Bottle Neutral Hydrolysis Depolymerisation Using Process Simulation and Response Surface Methodology

The global surge in plastic production has led to a concerning accumulation of durable plastic waste in landfills and the environment. To address this issue, the depolymerization of waste polyethylene terephthalate (PET) through neutral hydrolysis has been proposed as a chemical recycling solution. Despite its potential environmental benefits, the endothermic nature of this process at high temperatures has raised doubts about its commercial feasibility. In response, this study was conducted to assess optimal conditions for waste PET depolymerization using neutral hydrolysis in a continuous stirred tank reactor with zinc acetate as a catalyst. Process simulation, aimed to manufacture pure terephthalic acid (TPA) and ethylene glycol from pelletized post-consumer PET bottles, was conducted with Aspen Plus Version 11. Sensitivity analysis explored the impact of factors such as reaction temperature, reaction time, PET flake size, and catalyst to PET ratio on both PET conversion and TPA yield. The study found that PET depolymerization increased with decreasing particle size, longer reaction times, increasing catalyst to PET ratio and reaction temperatures within the range of 200–240°C. Optimizing the process through response surface modelling revealed that key parameters for neutral hydrolysis considering a mean particle size of 20 mm were the ratio of water to PET, temperature, pressure, and reaction time with optimal values of 5:1, 225°C, 30 bar, and 67.5 min respectively. The model's reliability was confirmed through variance analysis, emphasizing the significance of main and interaction effects in the regression model.

Enhancing efficiency in ethanol production from high solid corn stover: Insights into enzymatic hydrolysis parameters and cellulase recovery

BackgroundThe simultaneous saccharification and co-fermentation (SSCF) at high solid loading is an effective approach to improve the economic feasibility of bioethanol. MethodsIn this study, the high-solid SSCF of superfine grinding corn stover was treated with cheap and readily available deionized water (DW) instead of sodium citrate buffer solution (SCBS). Additionally, the evaluation of temperature, enzyme loading, solid loading, and cellulose recovery were carried out to determine their impact on ethanol production. Significant FindingsThe results of the analysis indicated that replacing SCBS with DW had negligible effects on the SSCF of ethanol and byproducts (acetic acid and glycerol). The ethanol yield increased by 18 % at 35 °C compared to the yield at 30 °C. As enzyme loading increased, more cellulose active sites in corn stover were bound by cellulase, which increased the ethanol yield by improving the efficiency of enzymatic hydrolysis. The SSCF process didn't incorporate any buffer, resulting in an even higher ethanol titer (55.42 g/L). Furthermore, the cellulase productivity increased by 71 % after recovery, compared to the non-recovery. The results indicated that the optimized SSCF process is a potential technique for producing bioethanol on a commercial level because it improves the production efficiency while keeping costs low.

Monocomponent Biosorption of Copper Ions (II) onto Nanocrystalline Cellulose from Coconut Husk Fibers

Introduction: Nanocrystalline cellulose (NCC) is one of the most suitable cellulose derivatives for the treatment of wastewater. Various agricultural wastes have been used for the extraction of NCC. Coconut wastes have been widely studied as potential adsorbents for the removal of pollutants, including dyes and heavy metals. Methods: In this work, nanocrystalline cellulose (NCC) was successfully isolated from coconut husk fibers through alkaline pretreatment accompanied by sulfuric acid hydrolysis. Then, the ability of NCC to adsorb Cu2+ from aqueous solution in batch studies was investigated. Results: Results indicated that the optimal hydrolysis parameters were achieved at 50° C for 45 min with 64% sulfuric acid to extract NCC as rod-like particles with diameters between 4-10 nm. The potential of NCC as a biosorbent to remove copper ions (Cu2+) from aqueous solution was investigated in terms of batch mode and maximum adsorption capacity (qm) of 79.491 mg/g of Cu2+. The adsorption efficiency of Cu2+ions increased with an increase in the adsorbent dosage, decreased with an increase in the initial concentration of contaminant, and increased with the contact time. Under optimal conditions, adsorption kinetic followed a pseudo-second-order kinetic model and the adsorption isotherm fitted most closely with the Langmuir model. Conclusion: According to a literature review, NCC from coconut husk fibers has not been used for the adsorption of heavy metals, mainly copper ions. This study shows that NCC from coconut husk fibers can be used as a low-cost and environmentally friendly adsorbent for the removal of Cu2+ from aqueous solutions.

Potential of Marine Bacterial Metalloprotease A69 in the Preparation of Peanut Peptides with Angiotensin-Converting Enzyme (ACE)-Inhibitory and Antioxidant Properties.

Marine bacterial proteases have rarely been used to produce bioactive peptides, although many have been reported. This study aims to evaluate the potential of the marine bacterial metalloprotease A69 from recombinant Bacillus subtilis in the preparation of peanut peptides (PPs) with antioxidant activity and angiotensin-converting enzyme (ACE)-inhibitory activity. Based on the optimization of the hydrolysis parameters of protease A69, a process for PPs preparation was set up in which the peanut protein was hydrolyzed by A69 at 3000 U g-1 and 60 °C, pH 7.0 for 4 h. The prepared PPs exhibited a high content of peptides with molecular weights lower than 1000 Da (>80%) and 3000 Da (>95%) and contained 17 kinds of amino acids. Moreover, the PPs displayed elevated scavenging of hydroxyl radical and 1,1-diphenyl-2-picryl-hydrazyl radical, with IC50 values of 1.50 mg mL-1 and 1.66 mg mL-1, respectively, indicating the good antioxidant activity of the PPs. The PPs also showed remarkable ACE-inhibitory activity, with an IC50 value of 0.71 mg mL-1. By liquid chromatography mass spectrometry analysis, the sequences of 19 ACE inhibitory peptides and 15 antioxidant peptides were identified from the PPs. These results indicate that the prepared PPs have a good nutritional value, as well as good antioxidant and antihypertensive effects, and that the marine bacterial metalloprotease A69 has promising potential in relation to the preparation of bioactive peptides from peanut protein.