Acid Pretreatment Research Articles

A Comparative Study on the Effects of Chemical and Hydrothermal Pretreatment Methods on the Valorization of Lignocellulose Agricultural Waste (Sugarcane Bagasse)

To effectively valorize agricultural waste (sugarcane bagasse) through biorefinery process, pretreatment which can be carried out in several ways is inevitable. This study explored the effects of chemical (acid and alkaline) and hydrothermal (steaming and autoclave) pretreatment methods on reducible sugar and ethanol yield from sugarcane bagasse. Acid pretreatment chemicals which include hydrogen peroxide and acetic acid were mixed together with sugarcane residue and heated at 85 oC for one hour. In alkaline pretreatment sodium hydroxide was mixed with the sugarcane waste and allow to incubate at 50 oC for one hour. The steaming approach involved using a steam distillation equipment. The sugarcane bagasse was first placed in a steam bag and then into a steam distillation unit which was steamed over a heating mantle for an hour. Autoclave pretreatment method used a stove type autoclave to disintegrate the processed sugarcane residue at 121oC. Each of these pretreated samples underwent independent hydrolysis and simultaneous saccharification and fermentation operations. Sugar yield was determined by the 3,5-dinitrosalicylic acid method, whereas the bioethanol yield was determined from refractometer readings. Sugarcane bagasse pretreated with acids gave a sugar yield of 995.567 mg/l and ethanol concentrations of 1.7303% in both enzymatic and acid hydrolysis, and 2.0758% ethanol concentration in simultaneous saccharification and fermentation process. Alkaline-pretreated sample gave a fermentable sugar yield of 441.2591 mg/l with 0.8655%, 0.6938%, and 1.73033% ethanol concentrations from enzymatic hydrolysis, acid hydrolysis and simultaneous saccharification and fermentation processes respectively. Steaming yielded 913.4849 mg/l of fermentable sugar, whereas the ethanol concentrations in the enzymatic hydrolysis, acid hydrolysis and simultaneous saccharification and fermentation methods were 1.2121%, 0.6938%, and 0.8666% respectively. Autoclave pretreatment resulted in a fermentable sugar yield of 800.9 mg/l with ethanol concentration of 1.3848% in both the enzymatic and acid hydrolysis, while that of simultaneous saccharification and fermentation was 1.0393%.

Alleviating effect of chlorogenic acid on oxidative damage caused by hydrogen peroxide in bovine intestinal epithelial cells.

Chlorogenic acid (CGA) is a polyphenol substance contained in many plants, which has good antioxidant activity. This experiment aimed to explore the protective effects of CGA on hydrogen peroxide (H2O2)-induced inflammatory response, apoptosis, and antioxidant capacity of bovine intestinal epithelial cells (BIECs-21) under oxidative stress and its mechanism. The results showed that compared with cells treated with H2O2 alone, CGA pretreatment could improve the viability of BIECs-21. Importantly, Chlorogenic acid pretreatment significantly reduced the formation of malondialdehyde (MDA), lowered reactive oxygen species (ROS) levels, and enhanced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) (P<0.05). In addition, CGA can also improve the intestinal barrier by increasing the abundance of tight junction proteins claudin-1 and occludin. Meanwhile, CGA can reduce the gene expression levels of pro-inflammatory factors Interleukin-6 (IL-6) and Interleukin-8 (IL-8), increase the expression of anti-inflammatory factor Interleukin-10 (IL-10), promote the expression of the nuclear factor-related factor 2 (Nrf2) signaling pathway, enhance cell antioxidant capacity, and inhibit Nuclear Factor Kappa B (NF-κB) the activation of the signaling pathway reducing the inflammatory response, thereby alleviating inflammation and oxidative stress damage.

Enhanced Bioethanol Production from Corn Stover Using Choline Chloride and Lactic Acid Pretreatment: A Gravimetric analysis Approach

The transition to renewable energy sources necessitates the development of efficient and sustainable bioethanol production methods. This study investigates the use of a deep eutectic solvent (DES) blend of choline chloride and lactic acid for the pretreatment of corn stover, a widely available lignocellulosic biomass, to enhance cellulose yield and bioethanol production. The gravimetric method was employed to quantify cellulose yield post-pretreatment, providing a direct assessment of pretreatment efficacy. The study further evaluated the subsequent steps of enzymatic hydrolysis, fermentation, and distillation to determine the overall bioethanol yield. Results demonstrated that the choline chloride and lactic acid blend effectively disrupted the lignocellulosic structure of corn stover, significantly increasing cellulose accessibility and fermentable sugar release. The optimized pretreatment process led to a notable improvement in bioethanol yield, highlighting the potential of this method for commercial bioethanol production. This research contributes to the advancement of biofuel technologies and supports the broader goal of achieving sustainable energy solutions by demonstrating a viable approach to enhancing the efficiency and sustainability of lignocellulosic bioethanol production.

From bulk banana peels to active materials: Slipping into bioplastic films with high UV-blocking and antioxidant properties

Bananas are among the most produced fruits globally, and their industry generates substantial amounts of peels, which are currently underutilized. Therefore, a simple process was proposed to fully convert banana peel powder (BPP) into bioplastic films using mild pretreatments. The influence of the following variables on film performance was investigated: the type of BPP (unblanched versus blanched), the pretreatment solvent (water – i.e., hydrothermal pretreatment, HTP – or sulfuric acid solution – i.e., dilute acid pretreatment, DAP), and the addition or not of carboxymethyl cellulose (CMC) in the films. The tensile properties of the bioplastics were primarily affected by the presence of CMC, with the films containing 20 wt% of this biopolymer achieving a tensile strength up to 16 MPa. The water vapor permeability was not influenced by any of the studied variables. In contrast, the water contact angle was primarily affected by the pretreatment employed, with all films prepared by HTP displaying a hydrophobic surface. The UV-shielding properties of the materials were mainly influenced by the type of BPP, and all films blocked at least 98% of UV radiation. The antioxidant activity was influenced primarily by the type of BPP, as blanching banana peels helped preserve it. These films are, therefore, promising materials for active food packaging applications, which could contribute to a transition toward a circular bioeconomy.

Phosphoric Acid Pretreatment and Saccharification of Paper Sludge as a Renewable Material for Cellulosic Fibers

Phosphoric Acid Pretreatment and Saccharification of Paper Sludge as a Renewable Material for Cellulosic Fibers

Isolation of Polyphenols from Aqueous Extract of the Halophyte Salicornia ramosissima.

Polyphenols from residual non-food grade Salicornia ramosissima have health-promoting effects in feed, food, or nutraceutical applications. Therefore, the isolation of polyphenols is of interest from a series of environmentally friendly isolation methods with recyclable solvents. The isolation of polyphenols from non-food grade S. ramosissima was investigated using sequential membrane filtration with and without acid pretreatment, liquid-liquid extraction, resin adsorption, and centrifugal partition chromatography (CPC); analyzed by the Folin-Ciocalteu assay for total polyphenols; and finally analyzed using UPLC-TQMS in negative ion-spray mode for detection of 14 polyphenols. Sequential membrane filtration and acid hydrolysis indicated the polyphenols forming complexes with other compounds, retaining the polyphenols in the retentate fraction of large molecular weight cut-off membrane sizes. Conventional liquid-liquid extraction using sequential ethyl acetate and n-butanol showed most polyphenols were extracted, apart from chlorogenic acids, indicating a low isolation efficiency of higher polarity polyphenols. Analysis of the extract after resin adsorption by Amberlite XAD-4 resin showed high efficiency for separation, with 100% of polyphenols adsorbed to the resin after 13 bed volumes and 96.7% eluted from the resin using ethanol. CPC fractionations were performed to fractionate the concentrated extract after resin adsorption. CPC fractionations of the 14 polyphenols were performed using an organic or aqueous phase as a mobile phase. Depending on the mobile phase, different compounds were isolated in a high concentration. Using these easily scalable methods, it was possible to comprehensively study the polyphenols of interest from S. ramosissima and their isolation mechanics. This study will potentially lead the way for the large-scale isolation of polyphenols from S. ramosissima and other complex halophytes. The compounds of the highest concentration after CPC fractionation were isoquercitrin and hyperoside (155.27 mg/g), chlorogenic acid (85.54 mg/g), cryptochlorogenic acid (101.50 mg/g), and protocatechuic acid (398.67 mg/g), and further isolation using CPC could potentially yield novel polyphenol nutraceuticals.

Algal deterioration of PET (polyethylene terephthalate) plastic bottle in combination with physical and chemical pretreatments: A macrocosm study

Plastic pollution has become an environmental issue worldwide because of its slow degradation and persistent nature. Many traditional methods exist and are practiced here to handle and reuse plastic waste, but those need to be more capable of tackling increasing waste volume. Biological plastic waste management could be a sustainable way to ensure environmental quality. Therefore, this study aimed to screen the bio-deterioration of PET wastes using physical and chemical pretreatments. We kept PET samples in freshwater and marine water media designed to support algal growth and incubated those under direct or indirect sunlight or in dark conditions. We observed algal growth and measured deterioration of PET samples using the tensile strength test, FTIR, and viewed surface properties using FESEM. Acid pretreatment and exposure to direct sunlight left the PET most fragile. FTIR analysis also supported the observation, and changes in functional groups are evident. Heat pretreatment usually reduces the volume and thus increases strength. Bottles incubated under direct or indirect sunlight supported the algal growth. The most prevalent algal species found in freshwater environments include Volvox, Chlorella vulgaris, Craticula cuspidate, Navicula pupula, Synedra ulna, and marine environments include Palisada perforate, Ulva flexuosa, Cladoptera herpestica, and Blindingia minima. Algal growth increases the porosity and surface cracks of PET bottles. Though FTIR analysis did not show any change in functional groups, except for acid pretreatment, upon algal growth, the transmittance increase indicated decay of PET samples.

A Study on the Germination of Origanum acutidens L. Seeds Subjected to Pre-Treatment of Gibberellic Acid and Colchicine

In Türkiye, the general name for aromatic plant species belonging to the Lamiaceae family is “thyme”. However, species containing thymol/carvacrol type essential oil are considered “thyme”. Origanum acutidens is one of the thyme species that grows endemic in the Northeastern Anatolia Region of Türkiye. The low germination rate of its seeds is one of the factors limiting the studies conducted on this plant. This study was conducted to investigate the effects of different doses of colchicine and gibberellic acid on germination in O. acutident seeds. Seeds collected from the plant’s natural habitat at the end of the flowering period were used as plant material. The experiment was planned as control (only distilled water) and treatments consisting of three different gibberellic acid (GA3) [100 ppm (GA1), 200 ppm (GA2) and 300 ppm (GA3)] and four different colchicine doses [0.01 mM (C1), 0.02 mM (C2), 0.04 mM (C3) and 0.08 mM (C4)]. The applications were kept at 25±1 ⁰C for 12 hours. After the waiting period, all seeds were filtered and placed, 50 seeds each, in 9 cm diameter petri dishes between two layers of sterile filter paper sheets. The experiment was carried out in 4 replications. Some parameters of the germination (Germination rate (GR), Germination time (GT), Average germination time (AGT)) and early seedling period (Embryonal root length (ERL), Number of embryonal roots (NER), Root fresh weight (RFW), Root dry weight (RDW), Grass sheath length (GSH)) were measured and the results were statistically evaluated. In general, the highest values obtained from all evaluated germination (92.0% GR and 1.7 day AGT) and early seedling parameters (10.4 cm ERL, 4.6 NER, 0.095 g RFW, 0.028 g RDW and 3.6 cm GSL) were found to belong to the GA3 application. The lowest values obtained from the relevant parameters were obtained with the C4 application. In our study, it was observed that gibberellic acid applications significantly increased germination in this plant and positively increased the parameters related to germination. Based on the study results, we think that colchicine stimulates germination at certain rates, but causes death by having a toxic effect in increasing doses.

Isolation and Characterization of Enterobacter sp Capable towards Tolerating Degradation Products and Fermenting Pentoses

&lt;p&gt;The depletion of fossil fuel resources, in addition to the growing demand for energy, has prompted the development of renewable energies, including bioethanol from lignocellulosic biomass. The acid pretreatment of hemicellulose releases inhibiting compounds in addition to xylose. With the possibility of exploitation of lignocellulose as a fermentation substrate, we isolated an &lt;em&gt;Enterobacter &lt;/em&gt;characterized by its ability to ferment xylose and tolerate high concentrations of inhibitors. The selection was performed in media containing different carbon and energy sources; glucose, cellobiose, CMC, furfural and 5-HMF. Characterization strategies of the selected strain such as, xylose concentration (from 25 g liter-1 to 100 g liter-1), furfural (0 mM to 25 mM), cell immobilization, were used to quantify the maximum yield of ethanol produced. The results obtained show that our strain can ferment up to 100 g liter-1 of xylose in the presence of 20 mM furfural at 37°C to produce ethanol with a maximum yield of 2.22 g liter- 1 for 24 h under 160 rpm magnetic stirring. The results obtained in this study suggest that the isolated &lt;em&gt;Enterobacter &lt;/em&gt;sp. is a promising strain for the bioconversion of lignocellulosic biomass pretreatment hydrolysate into bioethanol.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Acidification and alkali precipitation for phosphorus recovery from municipal digested sludge

AbstractMunicipal digested sludge (MDS) has considerable phosphorus content that is between 1% and 15% in dry matter and it is a potential source for phosphorus recovery. A high amount of MDS is generated from sewage treatment plants in large cities and has many environmental concerns with its organic and inorganic constituents. In this study, phosphorus was recovered by precipitation with Ca(OH)2 and NaOH. Acid pretreatment was applied to MDS with H2SO4 and 58.7% of phosphorus was extracted from the solid phase to the liquid phase at pH 2. Up to 99% of dissolved phosphorus in the liquid phase was recovered with Ca(OH)2 and NaOH. Almost similar phosphorus precipitation rates were achieved with both bases but higher phosphorus contents (17% as P2O5) in precipitates were obtained by NaOH. The product obtained in this study can serve as a high‐quality raw material substitute for the low‐grade phosphate rocks (&lt;15% P2O5) commonly utilized in the phosphate industry. Furthermore, this research presents a practical, environmentally friendly and cost‐effective approach for sustainable sludge management and phosphorus production.

Upgrading dry acid pretreatment by post-hydrolysis for carbon efficient conversion of lignocellulose

Dry acid pretreatment (DAP) as a promising process for industrial biorefinery provide an efficient bioconversion of cellulose without free wastewater, although the partial xylan and lignin degrade to inhibitors or recondense. A biorefinery strategy for carbon efficient conversion of lignocellulose into bioethanol, xylose, and reactive lignin was developed by upgrading DAP with post-hydrolysis. The results showed that lignocellulose after mild DAP (175 °C, acid dosage of 15 mg/g dry material) obtained higher xylan recovery and lower inhibitors than that of general DAP. Subsequently, post-hydrolysis, simultaneous saccharification and ethanol fermentation were performed at solids loading of 20 wt% without detoxification and sterilization, resulting in xylose and ethanol yield of 71.8 % and 67.6 %. The fractionated lignin presented more reactive β-aryl ether linkages and less condensation than that from DAP. 66 % of lignocellulose carbon was recovered as ethanol, xylose and reactive lignin. This upgrading biorefinery strategy provided an easy-to-operate process for integrated utilization of lignocellulose.

Nanoporous Cu-Sn Intermetallic Material for Interconnects in Electronic Packaging

Nanostructured and nanoparticulate Cu-based materialshave emerged as viable replacements of conventional solder materials for realizing high-performing and reliable interconnection in today's 2.5D/3D electronic packaging. Unlike the traditional interconnects, those materials offer better compliance during the overall packaging routines. Owing to their highly developed surface area resulting of their uniform interconnected porosity, said nanomaterials also enable joint formation by sintering by thermal compression realized at high pressure and at much lower temperatures compared to bulk counterparts. Recently, sintering of nanoporous (np) Cu was demonstrated under high pressure and temperature after initial pre-treatment in acid for surface oxide removal. Separately, other studies have been focused on the attachment of Cu pillars to pads by using nanoparticulate Cu pastes as sintering material. The ultimate goal is to develop materials that facilitate a highly effective and durable chip-to-substrate interconnection.In this report, we discuss the development and use of nanoporous uniform and continuous CuSn films for low-temperature joint formation. The novelty of this work is realized through the introduction of tin (Sn) to work along with the np-Cu structure for ensuring lower sintering temperatures with a goal of producing packaging interconnects based on CuSn intermetallic compound (IMC). The addition of Sn to the np-Cu system is performed using a bottom-up, all-electrochemical synthetic approach (see Figure 1). The method is founded on the initial synthesis of thin films of np-Cu by dealloying of Cu-Zn alloys, followed by a conformal coating with a thin layer of Sn. The main goal of the proposed approach is to form a np-CuSn composite that upon sintering at high temperature and pressure, transitions into a densely compressed Cu3Sn IMC bonding material. Realized accordingly as interconnect layer, said material ensures good stability at high current densities (greater than 1×105 A ⋅ cm2 ) and low electrical resistivity (equal or less than 8.5 µΩ ⋅ cm).The synthetic details and then the applicability of the Cu-Sn nanomaterials obtained using the approach for synthesis of a low-temperature joint formation material are also discussed. The Sn-coating process was administered by galvanic pulse plating, which was optimized to provide a conformal Sn coating and thus, to retain the initial np-Cu overall porous structure. Another optimization effort was made for ensuring a Sn atomic fraction that allows for the formation of Cu6Sn5 IMC. After the optimization process for determining the necessary plating conditions for reaching mostly Cu6Sn5 composition ratio, the material was subjected to sintering at temperatures in the range from 300ºC to 200oC, and at a pressure of 20 MPa. We found that the joints formed were heavily densified and consisted mainly of Cu3Sn IMC. The report presents the new approach as a facile and cost-effective method for synthesizing nanostructured Cu-Sn films as viable candidates for a new-generation of interconnect materials together with the demonstration of assembly processes that optimize robustness and reliability. The discussion also shows the proposed approach’s applicability by realization of low-temperature sintering of nanostructured CuSn films in pre-designed fine pitch assemblies. Figure 1: Schematic representation demonstrating key steps of the approach for synthesis of np-CuSn composites. Figure 1

Hydrodynamic cavitation-assisted acid pretreatment and fed-batch simultaneous saccharification and co-fermentation for ethanol production from sugarcane bagasse using immobilized cells of Scheffersomyces parashehatae

A new alternative for hydrodynamic cavitation-assisted pretreatment of sugarcane bagasse was proposed, along with a simultaneous saccharification and co-fermentation (SSCF) process performed in interconnected columns. Influential variables in the pretreatment were evaluated using a statistical design, indicating that an ozone flow rate of 10 mg min−1 and a pH of 5.10 resulted in 86 % and 72 % glucan and xylan hydrolysis yields, respectively, in the subsequent enzymatic hydrolysis process. Under these optimized conditions, iron sulfate (15 mg L−1) was added to assess Fenton pretreatment, resulting in glucan and xylan hydrolysis yields of 92 % and 71 %, respectively, in a material pretreated for 10 min. In SSCF, ethanol volumetric productivities of 0.33 g L−1 h−1 and of 0.54 g L−1 h−1 were obtained in batch and fed-batch operation modes, achieving 26 g L−1 of ethanol in 48 h in the latter mode.

Fully Integrated Microfluidic Platform for Multiplexed Detection of Hunov by a Dynamic Confined-Space-Implemented One-Pot Rpa-Lamp System.

Human norovirus (HuNoV) is the leading cause of nonbacterial acute gastroenteritis, which is highly infectious, rapidly evolving, and easily transmitted through feces. The accurate and early detection of HuNoV subtypes is essential for effective treatment, early surveillance, risk assessment, and disease prevention. In this study, a portable multiplex HuNoV detection platform that combines integrated microfluidics and cascade isothermal amplification, using a streamlined protocol for clinical fecal-based diagnosis is presented. To overcome the problems of carryover contamination and the incompatibility between recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP), a Dynamic confined-space-implemented One-pot RPA-LAMP colorimetric detection system (DORLA) is developed by creating a hydrogen bond network. The DORLA system exhibits excellent sensitivity, with detection limits of 10copiesµL-1 and 1copyµL-1 for HuNoV GI and GII, respectively. In addition, a portable diagnostic platform consisting of a thermostatic control module and an integrated 3D-printed microfluidic chip for specific HuNoV capture, nucleic acid pretreatment, and DORLA detection, which enables simultaneous diagnosis of HuNoV GI and GII is developed. A DORLA-based microfluidic platform exhibits satisfactory performance with high sensitivity and portability, and has high potential for the rapid point-of-care detection of HuNoV in clinical fecal samples, particularly in resource-limited settings.

Obtain high quality hydrochar from waste activated sludge with low nitrogen content using acids and alkali pretreatment by enhancing hydrolysis and catalyzation

Hydrolysis has been recognized as the rate-limiting step of waste activated sludge hydrothermal carbonization, resulting in a low degree of carbonization with partial unconverted feedstock and a high nitrogen content in hydrochar. In the current study, acids and alkali pretreatment was adopted to accelerate solubilization and hydrolysis of carbohydrates and proteins, catalyze carbonization, and obtain high quality hydrochars with low nitrogen content. The nitrogen content decreased significantly to 1.05% and 0.94% with acids and alkali pretreatment at pH of 1 and 13, respectively, from 1.80% without pretreatment. The fuel properties of hydrochars were improved with acids pretreatment at pH of 1 and 4, but reduced with alkali pretreatment at pH of 13. On the contrary, the thermal decomposition stability of hydrochars were improved with alkali pretreatment at pH of 13, but reduced with acids pretreatment at pH of 1 and 4. Acids pretreatment led to enhanced degradation of organic substances and formation of more small-molecule acidic compounds, which promoted the aromatization reaction and increased the higher heating values and organic matter contents in hydrochars. Organic matters were mostly released to the aqueous phase with alkali pretreatment at pH of 13, resulting in lower organic matter content in hydrochar.

Ex vivo investigation of betaine and boric acid function as preprotective agents on rat synaptosomes to be treated with Aβ (1-42).

Recent evidence suggests that ferroptosis, an iron-dependent cell death process, may be involved in Alzheimer's disease (AD) pathology. The study evaluated the therapeutic potential of betaine and boric acid (BA) pretreatment administered to rats for 21 days in AD. Then, the rats were sacrificed, and morphological and biochemical analyses were performed in brain tissues. Next, an ex vivo AD model was created by applying amyloid-β (Aβ1-42) to synaptosomes isolated from the brain tissues. Synaptosomes were analyzed with micrograph images, and protein and mRNA levels of ferroptotic markers were determined. Betaine and BA pretreatments did not cause any morphological and biochemical differences in the brain tissue. However, Aβ (1-42) administration in synaptosomes increased the levels of acyl-CoA synthetase long chain family member-4 (ACSL4), transferrin receptor-1 protein (TfR1), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) and decreased the levels glutathione peroxidase-4 (GPx4) and glutathione (GSH). Moreover, ACSL4, GPx4, and TfR1 mRNA and protein levels were similar to the ELISA results. In contrast, betaine and BA pretreatments decreased the levels of ACSL4, TfR1, MDA, and 8-OHdG in synaptosomes incubated with Aβ1-42, while promoting increased levels of GPx4 and GSH. In addition, betaine and BA pretreatments completely reversed ACSL4, GPx4, and TfR1 mRNA and protein levels. Therefore, betaine and BA pretreatments may contribute to the prevention of neurodegenerative damage by supporting antiferroptotic activities.

Nitrite acts as the key “switch” governing the free nitrous acid pretreatment in anaerobic digestion: A comprehensive mechanism of abiotic, bioinformatics and bioenergetics effects

Free nitrous acid (FNA) pretreatment has been an effective and environmentally-friendly strategy to improve anaerobic digestion (AD) performance, and the mechanism was generally ascribed to the abiotic role of enhancing substrate solubilization. However, a comprehensive understanding of FNA is lack considering the different biotic roles on various steps, microbes and functional genes, as well as the variation of thermodynamic conditions. Herein, FNA pretreatment significantly enhanced the AD performance of food waste (FW), and the maximum increment of methane yield (36.45 %) was observed for FNA level of 1.42 mg HNO2 − N/L. Nevertheless, FNA exhibited an inhibition-to-enhancement effects as the AD process proceeds, and the introduced nitrite was the key “switch”. Initially, the abiotic effects of FNA reduced the molecular weight of components in FW, benefiting the solubilization and formation of available organics (glucose and amino acid). The individual steps experiment confirmed that residual nitrite severely inhibited methanogenesis rather than hydrolysis and acidogenesis, which resulted in the decrement of methane yield and accumulation of VFAs. Meanwhile, the methanogens (Methanothrix and Methanobacterium) and genes involved in methanogenesis metabolisms (aceticlastic and hydrogenotrophic pathways) were downregulated. However, with the elimination of nitrite, the microbial activities and gene expressions restored and were even enhanced, and Gibbs-energy-based analysis suggested that accumulated VFAs provided favorable thermodynamic conditions for subsequent methanogenesis. This study firstly proved that the abiotic breakdown of macromolecule components, selective and reversible inhibition on microbes and functional genes induced by nitrite and varying thermodynamic conditions together governed the FNA affecting the AD process of FW.

Endothelial Cell Calcium Influx Mediates Trauma-induced Endothelial Permeability.

We aimed to investigate if ex vivo plasma from injured patients causes endothelial calcium (Ca2+) influx as a mechanism of trauma-induced endothelial permeability. Endothelial permeability after trauma contributes to post-injury organ dysfunction. While the mechanisms remain unclear, emerging evidence suggests intracellular Ca2+ signaling may play a role. Ex vivo plasma from injured patients with "Low Injury/Low Shock" (injury severity score [ISS]<15, base excess [BE])≥-6mEq/L) and "High Injury/High Shock" (ISS≥15, BE<-6mEq/L) were used to treat endothelial cells. Experimental conditions included Ca2+ removal from the extracellular buffer, cyclopiazonic acid pre-treatment to deplete intracellular Ca2+ stores, and GSK2193874 pre-treatment to block the TRPV4 Ca2+ channel. Live cell fluorescence microscopy and ECIS were used to assess cytosolic Ca2+ increases and permeability, respectively. Western blot and live cell actin staining were used to assess myosin light chain (MLC) phosphorylation and actomyosin contraction. Compared to Low Injury/Low Shock plasma, High Injury/High Shock induced greater cytosolic Ca2+ increase. Cytosolic Ca2+ increase, MLC phosphorylation, and actin cytoskeletal contraction were lower without extracellular Ca2+ present. High Injury/High Shock plasma did not induce endothelial permeability without extracellular Ca2+ present. TRPV4 inhibition lowered trauma plasma-induced endothelial Ca2+ influx and permeability. This study illuminates a novel mechanism of post-injury endotheliopathy involving Ca2+ influx via the TRPV4 channel. TRPV4 inhibition mitigates trauma-induced endothelial permeability. Moreover, widespread endothelial Ca2+ influx may contribute to trauma-induced hypocalcemia. This study provides the mechanistic basis for the development of Ca2+-targeted therapies and interventions in the care of severely injured patients.

An efficient chemoenzymatic approach to produce galactose from red macroalgae biomass and its valorization

Marine biomass is receiving much attention as the third-generation feedstock owing to its advantages over terrestrial biomass. Red macroalgae have an impressive high carbohydrate content, with galactose as the most abundant monosaccharide. However, the technology for producing galactose with a high yield and its valorization is not yet available. This study described an efficient chemoenzymatic approach toward upgrading of red macroalgae (Gelidium amansii) into value-added products (taking galactonic acid as an example). With the aid of microwave-assisted maleic acid pretreatment, galactose was obtained with an excellent yield of 92.7%. Various inhibitors were simultaneously generated and their inhibition effects on biocatalysis were overcame by genetic and bioprocess engineering. Finally, the galactose in the hydrolysate was converted into galactonic acid with a yield of 100% by engineered Pseudomonas putida. This approach can be easily expanded to other galactose-derived products and promotes green development of marine biomass biorefinery.

Simultaneous saccharification and fermentation residues as potential sources of phenolics by fast pyrolysis (Py-GC/MS) and alkaline hydrolysis

Unlike 1 G bioethanol, the success of 2 G technology faces difficulties. The economic difficulties of 2 G bioethanol can be solved with an additional income in by-products, mainly from lignin. The present study investigated the generation of phenolics via fast pyrolysis and alkaline hydrolysis using residues from saccharification and simultaneous fermentation (SSF) as substrate. The SSF residues were obtained from schemes with green coconut fiber (without chemical pretreatment) and corn cob (with previous acid pretreatment). Chemical composition, FTIR, and XRD analyses confirmed that the processing undergone by SSF residues altered the lignocellulose structure. Due to extractives removal and lignin increase, the fast pyrolysis experiments with SSF residues favored the generation of phenolics over C1-C4 products. Phenol was the main product in the pyrolysis of untreated green coconut fiber (14.64%) and SSF residue (13.51%), while the 2-methoxy-4-vinylphenol content in the bio-oil was doubled with the SSF corn cob residue (from 12.87% to 27.01%). SSF corn cob residue showed a high yield of hydroxynamic acids after alkaline hydrolysis with sodium hydroxide. The p-coumaric acid yield reached 4337 mg/100 g in experiments at 60 °C. Based on the results, the conversion of SSF residues appears as an alternative to obtain commercially appealing phenolics and may be attractive for 2 G bioethanol technology.