Alcohol Dehydrogenase Research Articles

Real-world safety and effectiveness of intravenous fomepizole in patients with ethylene glycol and methanol poisoning in Japan: results of a 7-year post-marketing surveillance study

ABSTRACT Background Fomepizole is a competitive alcohol dehydrogenase inhibitor used for the treatment of ethylene glycol and methanol poisoning. We evaluated the safety and effectiveness of fomepizole in patients with ethylene glycol or methanol poisoning in Japan. Research design and methods This retrospective post-marketing surveillance study conducted in Japan registered patients who received fomepizole intravenous infusion per the package insert (January 2015−June 2022). Endpoints included adverse drug reactions/infections (ADRs), arterial blood pH, and treatment outcomes. Results Of 147 patients registered (91 institutions), 131 and 126 were included in the safety and effectiveness analysis sets, respectively. Mean age was 43.6 years, and 66.4% were male. Mean time from poison ingestion to treatment was 15.1 hours; 66.4% received concomitant hemodialysis. No serious ADRs were reported. ADRs were reported in seven patients; the most-reported ADR was vomiting (2.3%). Seven patients died, 105 survived without sequelae, and 19 survived with sequelae. Most common sequelae were renal failure or renal dysfunction. Mean arterial blood pH increased to 7.4 by 4 hours of treatment, remaining stable for 24 hours post-treatment. Conclusions Fomepizole is well tolerated and helps improve clinical outcomes in patients with ethylene glycol or methanol poisoning in Japan. Trial registration Japanese Pharmaceutical Information Center (JapicCTI-152817).

Host Plants and Fertilization Mediated Life History of American Serpentine Leaf Miner, Liriomyza trifolii (Burgess) (Diptera: Agromyzidae).

Herbivorous insects depend on the host plant to optimize their overall reproductive success, and balanced fertilization may alter the plant's quality against herbivory. Life history traits of the Liriomyza trifolii (Burgess) were determined under laboratory conditions using either unfertilized and fertilized plants of bean [Phaseolus vulgaris L. (Fabaceae)], chrysanthemum [Chrysanthemum × morifolium (Asteraceae)], potato [Solanum tuberosum (Solanaceae)], bell pepper [Capsicum annuum (Solanaceae)], and tomato [Solanum lycopersicum (Solanaceae)]. Results indicated that L. trifolii completed development on all studied unfertilized and fertilized plants. Nevertheless, a higher performance of the leaf miner was observed on bean and bell pepper plants compared to the other plants. Furthermore, there was an interaction of the host plant and fertilization with Calcium Aria or Sitam negatively affecting the fitness-related traits of the leaf miner. Application of these fertilizers resulted in delayed immature development of L. trifolii, decreased survival rate, and reduced adult longevity and fecundity. The activity of cinnamyl alcohol dehydrogenase (CAD), peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) enzymes, as well as phenolic, flavonoid, and lignin content were higher in Calcium Aria + Sitam fertilized plants, intermediate in Calcium Aria and Sitam treated plants, and the lower in unfertilized plants. The development and survival of L. trifolii on different host plants, considering fertilization options, become important for deploying cultural control practices against this important pest species.

Insight into flavor changes in bighead carp (Aristichthys nobilis) fillets during storage based on enzymatic, microbial, and metabolism analysis

The flavor alterations in bighead carp subjected to varying storage temperatures and the underlying metabolic mechanism were elucidated. Analysis of volatile flavor compounds, electronic nose, free amino acids, ATP-related compounds, and sensory evaluations uncovered a progressive flavor deterioration during storage, especially at 25 °C. Metabolomics-based flavor relating component profiling analysis showed that free fatty acids formed various fatty aldehydes including (E, E)-2,4-heptadienal and nonanal under lipoxygenase catalysis. Alcohol dehydrogenase and alcohol acyltransferases were intimately involved in alcohol and ester generation, while alkaline phosphatase, 5′-nucleotidase, and acid phosphatase were closely associated with IMP, Hx, and HxR conversion, respectively. Aeromonas, Serratia, Lactococcus, Pseudomonas, and Peptostreptococcus notably influenced flavor metabolism and enzyme activities. The metabolism disparities of valine, leucine, isoleucine, lysine, and α-linolenic acid could be the primary factors contributing to flavor metabolism distinctions. This study offers novel insights into the flavor change mechanisms and potential regulation strategies of bighead carp during storage.

Abstracts of the Toxicology and Poisons Network Australasia (TAPNA) 2024 Annual Scientific Meeting (Melbourne, Victoria).

Background Toxic alcohol poisoning is uncommon in New South Wales (NSW). Inadequate treatment causes significant morbidity and mortality. Management priorities are diagnosis, and early treatment with alcohol dehydrogenase (ADH) blockade and extracorporeal treatments (ECTRs). Fomepizole is a potent ADH inhibitor available in Australia but its use and role, compared to ethanol, is uncertain. We describe the epidemiology, management and outcomes of suspected significant toxic alcohol poisonings in NSW. Methods We searched databases of the NSW Poisons Information Centre, five tertiary clinical toxicology services and Statewide retrieval services. We included all patients with known or suspected toxic alcohol poisoning referred to a clinical toxicologist and included all patients who received treatment with ADH blockade. Patients were subdivided on the basis of whether toxic alcohol poisoning was confirmed or excluded. Data extracted included demographics, details of the exposure, management (including treatment delays and monitoring of ethanol therapy (if received), outcomes and complications). Categorical data were described as frequencies and percentages, and continuous data were described as median and interquartile ranges. Results Among 198 patients between 2015 and 2023, 36 fulfilled inclusion criteria. Toxic alcohols ingested included ethylene glycol (29), diethylene glycol (5), and methanol (1); 12 co-ingested ethanol. Toxic alcohol poisoning was confirmed by history or specific assays in 35 cases. Delay to presentation was median 3 h (IQR 2–9; 20). Delay from hospital presentation to initiating ADH blockade was median 3 h (IQR 2–7; 27). Three were diagnosed after developing unexplained AKI. Four patients received fomepizole and 27 received ethanol therapy. In the 20 patients who received ethanol for ≥24 h, blood ethanol concentrations were measured median 5.5 times (IQR 4-11) in the first 24 h, and 9 had at least 2 subtherapeutic levels. 21 patients received ECTR, which was initiated within median 7 h (IQR 4-11). Excluding 3 patients who did not receive treatment due to delayed diagnosis, 18 developed complications (acute kidney injury 16, neurotoxicity 8, death 3). In 18 ethanol-treated patients, fomepizole would have offered key advantages, including avoiding ICU (9), facilitating transport (7), and delaying and/or foregoing ECTR (6). Discussion There are potential benefits of fomepizole use in NSW.

Merging Organolithium Chemistry and Stereoselective Biocatalysis: Transformation of Aromatic Nitriles into Chiral Alcohols

AbstractThe combination of RLi‐mediated organic transformations (under air and at room temperature) with a subsequent stereoselective biocatalytic reaction is for the first time presented. Most of the previous asymmetric chemoenzymatic routes have been limited to the concomitant or sequential combination of transition metals/organocatalysts with enzymes. However, the use of polar organometallic reagents (RLi) in the design of these stereoselective hybrid protocols has been totally neglected, as far as we are concerned. Thus, in this work, the combination of organolithium chemistry and asymmetric biocatalysis is described for the first time in a one‐pot fashion. The chemoenzymatic approach converts a series of nitriles into chiral alcohols consisting of two steps, where the key item was the finding of suitable conditions to adapt the reactivities of organolithiums and alcohol dehydrogenases (ADHs) in the same recipient. The organolithium addition occurred with total chemoselectivity (no side reactions were observed) under neat conditions and room temperature leading to the corresponding imines, which were hydrolyzed using a buffer, and adjusting the pH for the subsequent ADH action. Commercial and made in house overexpressed ADHs allowed to produce chiral alcohols with excellent selectivities and good overall yields. The different behavior displayed for the reductive enzymes in the presence of diethyl ether clearly influenced in the decision to let the organolithium solvent evaporate under open‐air conditions before developing the bioreduction step. Our results demonstrate the importance of the fine orchestration of the reaction conditions for the development of efficient hybrid chemoenzymatic cascades without the need of intermediate isolation/purification steps or compartmentalization of the different synthetic systems.

Inherited anoxia tolerance and growth performance can result in enhanced invasiveness in hybrid fish.

Northern hemisphere freshwater ecosystems are projected to experience significant warming and shortening of winter duration in this century. This change coupled with depletion of oxygen (hypoxia) will result in a shift toward fish species with higher optimal temperatures for growth and reproduction that can mitigate hypoxic stress. Here, we tested the assumption that reproduction between two distant species, i.e. anoxic-intolerant common carp (Cyprinus carpio) and anoxic-tolerant goldfish (Carassius auratus), results in the expression of genes responsible for ethanol synthesis (alcohol dehydrogenase and pyruvate dehydrogenase subunit E1β2). The expression of this ethanol-producing pyruvate decarboxylase pathway may transform the biochemical characteristics of progeny into anoxic-tolerant hybrids, expanding their suitable environmental range and potentially increasing invasiveness. Concurrently, a genetic strategy for improving fish tolerance to oxygen-depleted environments will be a valuable physiological trait in fish culture. Differential quantification of gene expression by analyzing mRNA revealed that, compared with koi×koi, koi female×goldfish male (F1 hybrid) possessed the pyruvate dehydrogenase subunit E1β2 gene construct, which was expressed at significantly greater levels in red muscle. The potential of this hybrid to both survive in extreme anoxic conditions and grow at elevated water temperatures would likely contribute to their ecological success.

The role of AdhE on ethanol tolerance and production in Clostridium thermocellum

Many anaerobic microorganisms use the bifunctional aldehyde and alcohol dehydrogenase, AdhE, to produce ethanol. One such organism is Clostridium thermocellum, which is of interest for cellulosic biofuel production. In the course of engineering this organism for improved ethanol tolerance and production, we observed that AdhE was a frequent target of mutations. Here, we characterized those mutations to understand their effects on enzymatic activity, as well ethanol tolerance and product formation in the organism. We found that there is a strong correlation between NADH-linked alcohol dehydrogenase (ADH) activity and ethanol tolerance. Mutations that decrease NADH-linked ADH activity increase ethanol tolerance; correspondingly, mutations that increase NADH-linked ADH activity decrease ethanol tolerance. We also found that the magnitude of ADH activity did not play a significant role in determining ethanol titer. Increasing ADH activity had no effect on ethanol titer. Reducing ADH activity had indeterminate effects on ethanol titer, sometimes increasing and sometimes decreasing it. Finally, this study shows that the cofactor specificity of ADH activity was found to be the primary factor affecting ethanol yield. We expect that these results will inform efforts to use AdhE enzymes in metabolic engineering approaches.

Molecular targets of PXR-dependent ethanol-induced hepatotoxicity in female mice

The pregnane X receptor (PXR, NR1I2), a xenobiotic-sensing nuclear receptor signaling potentiates ethanol (EtOH)-induced hepatotoxicity in male mice, however, how PXR signaling modulates EtOH-induced hepatotoxicity in female mice is unknown. Wild type (WT) and Pxr-null mice received 5 % EtOH-containing diets or paired-fed control diets for 8 weeks followed by assessment of liver injury, EtOH elimination rates, histology, and changes in gene and protein expression; microarray and bioinformatic analyses were also employed to identify PXR targets in chronic EtOH-induced hepatotoxicity. In WT females, EtOH ingestion significantly increased serum ethanol and alanine aminotransferase (ALT) levels, hepatic Pxr mRNA, constitutive androstane receptor activation, Cyp2b10 mRNA and protein, oxidative stress, endoplasmic stress (phospho-elF2α) and pro-apoptotic (Bax) protein expression. Unexpectedly, EtOH-fed female Pxr-null mice displayed increased EtOH elimination and elevated levels of hepatic acetaldehyde detoxifying aldehyde dehydrogenase 1a1 (Aldh1a1) mRNA and protein, EtOH-metabolizing alcohol dehydrogenase 1 (ADH1), and lipid suppressing microsomal triglyceride transport protein (MTP) protein, aldo–keto reductase 1b7 (Akr1b7) and Cyp2a5 mRNA, but suppressed CYP2B10 protein levels, with evidence of protection against chronic EtOH-induced oxidative stress and hepatotoxicity. While liver injury was not different between the two WT sexes, female sex may suppress EtOH-induced macrovesicular steatosis in the liver. Several genes and pathways important in retinol and steroid hormone biosynthesis, chemical carcinogenesis, and arachidonic acid metabolism were upregulated by EtOH in a PXR-dependent manner in both sexes. Together, these data establish that female Pxr-null mice are resistant to chronic EtOH-induced hepatotoxicity and unravel the PXR-dependent and −independent mechanisms that contribute to EtOH-induced hepatotoxicity.

A pH-dependent shift of redox cofactor specificity in a benzyl alcohol dehydrogenase of aromatoleum aromaticum EbN1

We characterise a reversible bacterial zinc-containing benzyl alcohol dehydrogenase (BaDH) accepting either NAD+ or NADP+ as a redox cofactor. Remarkably, its redox cofactor specificity is pH-dependent with the phosphorylated cofactors favored at lower and the dephospho-forms at higher pH. BaDH also shows different steady-state kinetic behavior with the two cofactor forms. From a structural model, the pH-dependent shift may affect the charge of a histidine in the 2′-phosphate-binding pocket of the redox cofactor binding site. The enzyme is phylogenetically affiliated to a new subbranch of the Zn-containing alcohol dehydrogenases, which share this conserved residue. BaDH appears to have some specificity for its substrate, but also turns over many substituted benzyl alcohol and benzaldehyde variants, as well as compounds containing a conjugated C=C double bond with the aldehyde carbonyl group. However, compounds with an sp3-hybridised C next to the alcohol/aldehyde group are not or only weakly turned over. The enzyme appears to contain a Zn in its catalytic site and a mixture of Zn and Fe in its structural metal-binding site. Moreover, we demonstrate the use of BaDH in an enzyme cascade reaction with an acid-reducing tungsten enzyme to reduce benzoate to benzyl alcohol.Key points•Zn-containing BaDH has activity with either NAD+or NADP+at different pH optima.•BaDH converts a broad range of substrates.•BaDH is used in a cascade reaction for the reduction of benzoate to benzyl alcohol.

Genome-wide identification of the CAD gene family and functional analysis of putative bona fide CAD genes in tobacco (Nicotiana tabacum L.).

Cinnamyl alcohol dehydrogenase (CAD) plays a crucial role in lignin biosynthesis, and the gene family encoding various CAD isozymes has been cloned and characterized in numerous plant species. However, limited information regarding the CAD gene family in tobacco is currently available. In this study, we identified 10 CAD genes in Nicotiana tabacum, four in N. tomentosiformis, and six in N. sylvestris. The nucleotide and amino acid sequences of these tobacco CADs demonstrate high levels of similarity, whereas the putative protein sequences conservatively possessed two Zn2+ binding motifs and an NADP(H) cofactor binding motif. Both NtCAD1 and NtCAD2 had conservative substrate binding sites, similar to those possessed by bona fide CADs, and evidence from phylogenetic analysis as well as expression profiling supported their role as bona fide CADs involved in lignin biosynthesis. NtCAD1 has two paralogous genes, NtCAD1-1 and NtCAD1-2. Enzyme activity analysis revealed that NtCAD1-1 and NtCAD1-2 had a high affinity to coniferyl aldehyde, p-coumaryl aldehyde, and sinapyl aldehyde, whereas NtCAD2 preferred coniferyl aldehyde and p-coumaryl aldehyde as substrates. The kinetic parameter assay revealed that NtCAD1-2 functions as the most efficient enzyme. Downregulation of both NtCAD1-1 and NtCAD1-2 resulted in reddish-brown stems without significant changes in lignin content. Furthermore, NtCAD1-1, NtCAD1-2, and NtCAD2 showed distinct expression patterns in response to biotic and abiotic stresses, as well as different phytohormones. Our findings suggest that NtCAD1-1 and NtCAD1-2 are involved in lignin biosynthesis, with NtCAD1-2 also participating in both biological and abiotic stresses, whereas NtCAD2 plays a distinct role mainly in responding to biological and abiotic stresses in tobacco.

ADH‐Catalyzed Biooxidation of (Hetero)aromatic sec‐Alcohols to Ketones Employing Vinyl Acetate as Acetaldehyde Surrogate

AbstractThe oxidation of sec‐alcohols is a common reaction in organic chemistry. We report a biocatalytic approach for oxidizing racemic (hetero)aromatic sec‐alcohols to the corresponding ketones. The reaction relies on employing freeze‐dried E. coli cells containing a recombinant variant of an alcohol dehydrogenase deduced from Lactobacillus kefir (E. coli/Lk‐ADH Prince) and vinyl acetate as an in situ acetaldehyde surrogate as oxidant. Biooxidations of a set of 20 racemic (hetero)aromatic alcohols were carried out in the presence of a catalytic amount of NADP+ cofactor, the biocatalyst, and vinyl acetate in an aqueous medium to generate the corresponding ketones with up to >99 % conv. Preparative scale (1.0 mmol; 100 mM in 10 mL) reactions led to obtaining ketones in the 56–83 % isolated yield range.

Ultraviolet‐B Stress Increases Epidermal UV‐Screening Effectiveness and Alters Growth and Cell‐Wall Constituents of the Brown Midrib bmr6 and bmr12 Mutants of Sorghum bicolor

ABSTRACTThe brown midrib bmr6 and bmr12 mutants of sorghum (Sorghum bicolor) have alterations to the phenylpropanoid pathway impairing the activity of cinnamyl alcohol dehydrogenase (CAD) and/or caffeate5/hydroxyferulate O‐methyl transferase (COMT) enzymes, which inhibit lignin synthesis. Interestingly, these phenylpropanoids can also act as sunscreen compounds in plants and potentially attenuate ultraviolet radiation. We examined the effects of ultraviolet‐B (UV‐B; 280–320 nm) exclusion on growth, cell‐wall constituents and UV‐screening abilities of bmr6, bmr12, a double mutant (bmr6 bmr12; dm) and wild‐type (WT) genotypes of S. bicolor. Plants were grown in a UV‐transparent greenhouse under filters that either transmitted 2.8% (Mylar) or 90% (Aclar) of UV‐B. The greenhouse experiment was a 2 × 4 (UV treatment × genotype) complete factorial design. Sorghum grown under reduced UV were 23% taller and had 22% fewer leaves. Among genotypes, the WT plants were 5%–12% taller than the bmr6, bmr12 and dm mutants. The near‐ambient UV‐B treatment group was more effective at UV screening and had a 16% higher UV‐screening effectiveness than those under reduced UV‐B. Sorghum plants with the bmr6 and dm genotypes had 8%–19% higher UV‐shield than the bmr12 and WT. Plants grown under the reduced UV‐B treatment had 5% less hemicellulose and 6% more cellulose in their cell walls. There were no overall treatment effects on bulk soluble phenolics, chlorophyll fluorescence (Fv/Fm) or lignin concentrations. These results are a possible indication that the bmr mutants of S. bicolor have a varied response to UV‐B exclusion due to alterations in the phenylpropanoid pathway leading to redistribution of metabolites.

Immobilised Alcohol Dehydrogenase and Ene‐Reductase Work in Concert to Reduce Cyclohex‐2‐enone in Bulk Organic Solvent

Enone reduction by ene reductase (ERED) has not been reported yet in bulk organic media probably due to expected challenges with the cofactor recycling using a second enzyme and the exchange of the NAD(P)‐cofactor between the two enzymes. Herein, the combination of an ERED from Zymomonas mobilis (NCR‐ERED) and Thermoanaerobacter ethanolicus alcohol dehydrogenase (TeSADH) has been found as an efficient biocatalytic redox system for the reduction of cyclohex‐2‐enone into cyclohexanol in bulk organic solvents. Both enzymes were successfully immobilised on three EziG supports, finding Coral as the most promising carrier for both of them. The highest enzymatic activities were found in hydrophobic solvents such as toluene and isooctane. It was observed that the control of water content and post‐immobilisation treatments enabled retention of enzyme activity. Both enzymes were co‐immobilised on the same bead together with NADP+, leading to the production of a self‐sufficient catalytic system, although the external supplementation of the nicotinamide cofactor was necessary for an efficient enzyme reuse. In this case, no ERED activity loss was detected after two additional cycles, while the ADH experienced less than 20% activity loss upon reuse.

Image Sensing of Gaseous Acetone Using Secondary Alcohol Dehydrogenase-Immobilized Mesh for Exhaled Air.

Human-borne acetone is a potent marker of lipid metabolism. Here, an enzyme immobilization method for secondary alcohol dehydrogenase (S-ADH), which is suitable for highly sensitive and selective biosensing of acetone, was developed, and then its applicability was demonstrated for spatiotemporal imaging of concentration distribution. After various investigations, S-ADH-immobilized meshes could be prepared with less than 5% variation by cross-linking S-ADH with glutaraldehyde on a cotton mesh at 40 °C for 15 min. Furthermore, high activity was obtained by adjusting the concentration of the coenzyme nicotinamide adenine dinucleotide (NADH) solution added to the S-ADH-immobilized mesh to 500 μM and the solvent to a potassium phosphate buffer solution at pH 6.5. The gas imaging system using the S-ADH-immobilized mesh was able to image the decrease in NADH fluorescence (ex 340 nm, fl 490 nm) caused by the catalytic reaction of S-ADH and the acetone distribution in the concentration range of 0.1-10 ppm-v, including the breath concentration of healthy people at rest. The exhaled breath of two healthy subjects at 6 h of fasting was quantified as 377 and 673 ppb-v, which were consistent with the values quantified by gas chromatography-mass spectrometry.

A Novel Sustainable and Self-Sufficient Biotechnological Strategy for Directly Transforming Sewage Sludge into High-Value Liquid Biochemicals.

Sewage sludge, as a carbon-rich byproduct of wastewater treatment, holds significant untapped potential as a renewable resource. Upcycling this troublesome waste stream represents great promise in addressing global escalating energy demands through its wide practice of biochemical recovery concurrently. Here, we propose a biotechnological concept to gain value-added liquid bioproducts from sewage sludge in a self-sufficient manner by directly transforming sludge into medium-chain fatty acids (MCFAs). Our findings suggest that yeast, a cheap and readily available commercial powder, would involve ethanol-type fermentation in chain elongation to achieve abundant MCFA production from sewage sludge using electron donors (i.e., ethanol) and acceptors (i.e., short-chain fatty acids) produced in situ. The enhanced abundance and transcriptional activity of genes related to key enzymes, such as butyryl-CoA dehydrogenase and alcohol dehydrogenase, affirm the robust capacity for the self-sustained production of MCFAs. This is indicative of an effective metabolic network established between yeast and anaerobic microorganisms within this innovative sludge fermentation framework. Furthermore, life cycle assessment and techno-economic analysis evidence the sustainability and economic competitiveness of this biotechnological strategy. Overall, this work provides insights into sewage sludge upgrading independent of additional carbon input, which can be applied in existing anaerobic sludge fermentation infrastructure as well as to develop new applications in a diverse range of industries.

The protective effects of aqueous extract of Schisandra sphenanthera against alcoholic liver disease partly through the PI3K-AKT-IKK signaling pathway

PurposeThis study aimed to investigated the key chemical components and the effect of the aqueous extract of Schisandra sphenanthera (SSAE) on alcoholic liver disease (ALD) and the related molecular mechanism. MethodsThis study employed UPLC-Q-TOF-MS/MS to identify the chemical compositions in SSAE. ALD rat model was established through oral administration of white spirit. Transcriptome sequencing, weighted gene co-expression network construction analysis (WGCNA), and network pharmacology were used to predict key compositions and pathways targeted by SSAE for the treatment of ALD. Enzyme-linked immunosorbent assay (ELISA), biochemical kits, hematoxylin-eosin (HE) staining, Western blotting (WB) analysis, and immunohistochemical analysis were used to validate the mechanism of action of SSAE in treating ALD. ResultsActive ingredients such as schisandrin A, schisandrol A, and schisandrol B were found to regulate the PI3K/AKT/IKK signaling pathway. Compared to the model group, the SSAE group demonstrated significant improvements in cellular solidification and tissue inflammation in the liver tissues of ALD model rats. Additionally, SSAE regulated the levels of a spartate aminotransferase (AST), alanine aminotransferase (ALT), alcohol dehydrogenase (ADH), and aldehyde Dehydrogenase (ALDH) in serum (P < 0.05); Western blotting and immunohistochemical analyses showed that the expression levels of phosphorylated PI3K, AKT, IKK, NFκB, and FOXO1 proteins were significantly reduced in liver tissues (P < 0.05), whereas the expression level of Bcl-2 proteins was significantly increased (P < 0.05). ConclusionThe active components of SSAE were schisandrin A, schisandrol A, and schisandrol B, which regulated the phosphorylation levels of PI3K, AKT, IKK, and NFκB and the expression of FOXO1 protein and upregulated the expression of Bcl-2 protein in the liver tissues of ALD rats. These findings indicate that SSAE acts against ALD partly through the PI3K-AKT-IKK signaling pathway. This study provided a reference for future research and treatment of ALD and the development of novel natural hepatoprotective drugs.

Structure modeling-based characterization of ChnD, the 6-hydroxyhexanoate dehydrogenase from Acinetobacter sp. strain NCIMB 9871

α,ω-Dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes are valuable building blocks for the production of biopolyesters and biopolyamides. One of the key steps in producing these chemicals is the oxidation of ω-hydroxycarboxylic acids using alcohol dehydrogenases (e.g., ChnD of Acinetobacter sp. NCIMB 9871). However, the reaction and structural features of these enzymes remain mostly undiscovered. Thereby, we have investigated characteristics of ChnD based on enzyme kinetics, substrate-docking simulations, and mutation studies. Kinetic analysis revealed a distinct preference of ChnD for medium chain ω-hydroxycarboxylic acids, with the highest catalytic efficiency of 18.0 mM−1s−1 for 12-hydroxydodecanoic acid among C6 to C12 ω-hydroxycarboxylic acids. The high catalytic efficiency was attributed to the positive interactions between the carboxyl group of the substrates and the guanidino group of two arginine residues (i.e., Arg62 and Arg266) in the substrate binding site. The ChnD_R62L variant showed the increased efficiency and affinity, particularly for fatty alcohols (i.e., C6–C10) and branched-chain fatty alcohols, such as 3-methyl-2-buten-1-ol. Overall, this study contributes to the deeper understanding of medium-chain primary aliphatic alcohol dehydrogenases and their applications for the production of industrially relevant chemicals such as α,ω-dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes from renewable biomass.

Enhanced co-production of hydrogen and ethanol from brown algae fermentation by supplementing nano zero-valent iron (nZVI)

Nano zero-valent iron (nZVI) has been shown to facilitate biofuel production, notably in hydrogen generation. However, its effect on bioethanol production is rarely studied, and even less so on its impact on hydrogen and ethanol co-production. This study therefore conducted ethanol-type hydrogen-producing fermentation with brown algae to explore the effect of nZVI. With the supplementation of nZVI, fermentation was accelerated and the production of hydrogen and ethanol were both significantly enhanced. At the optimal nZVI concentration of 100 mg/L, the production of hydrogen and ethanol increased by 71.44% and 65.11%, respectively. A high hydrogen yield of 2.32 mol/mol-mannitol was achieved. The ethanol yield (1.86 mol/mol-mannitol) reached 93% of the theoretical maximal yield with a high selectivity of 91.09%. Electron distribution analysis showed that nZVI increased the total electron amounts of fermentation, and directed more electrons to ethanol than hydrogen. The reduced redox potential (ORP) and increased NADH level further confirmed the role of nZVI. Moreover, nZVI fostered Fe2+ availability to hydrogen-producing bacteria, enhancing the enzymes hydrogenase and alcohol dehydrogenase, as well as cell biomass. The bioenergy conversion efficiency (BioECE) improved from 19.08% to 31.74% with 100 mg/L nZVI treatment. This study provided a first demonstration regarding the role of nZVI in hydrogen and ethanol co-production, highlighting the great potential of multiple bioenergy recovery from marine biomass.

Proteome and metabolome of Caryocar brasiliense camb. fruit and their interaction during development

Considered the symbol fruit of the Brazilian Cerrado, pequi (Caryocar brasiliense Camb.) is an exotic and much-appreciated fruit with an internal mesocarp (edible part) with an eye-catching golden yellow color. In an unprecedented way, this study characterized the proteome throughout pequi development. The most influential and essential transcription factors operating in the regulation of pequi ripening identified were members of the MAD-box family. A group of proteins related to the methionine cycle indicates the high consumption and recycling of methionine. However this consumption does not occur mainly for the biosynthesis of ethylene, a process dependent on methionine consumption. In the bioactive compounds presented, different proteins could be correlated with the presence of these phytochemicals, such as monodehydroascorbate reductase and ascorbate peroxidase in ascorbic acid recycling; pyruvate kinase, fructose bisphosphate aldolase and phytoene synthase with carotenoid biosynthesis; S-adenosylmethionine synthase 1 as a donor of methyl groups in the formation of trigonelline and aspartate aminotransferase as a biomarker of initial regulation of the trigonelline biosynthetic pathway; phenylalanine ammonia lyase, chorismate synthesis and chalcone-flavononone isomerase in the biosynthesis of phenolic compounds. Among the volatile organic compounds identified, the majority compound in pequi was ethyl hexanoate ester, with an area of 50.68 % in the ripe fruit, and in this group of esters that was the most representative, alcohol dehydrogenase, a fundamental enzyme in the synthesis of esters, was identified with an increase of approximately 7.2 times between the first and last stages. Therefore, an extensive group of proteins and some metabolites can serve as biomarkers of ripening in pequi, as most were more expressed in the last stage, which is the ripe fruit suitable for consumption.

Physiological Mechanisms of BvCPD Regulation in Sugar Beet Growth

Sugar beet is an important sugar crop, and its roots are mainly used for processing raw materials to produce products such as sugar, molasses, and saccharin, as well as being used as fodder for livestock. BvCPD, a key enzyme gene for brassinosteroid (BR) synthesis, regulates the development of parenchyma cells and vascular bundles by promoting BR synthesis, which promotes the expansion of the sugar beet taproot and influences the growth, development, and yield of sugar beets. This study investigated the impact of BvCPD on the physiological metabolism of sugar beet utilizing BvCPD overexpression, silent, and wild-type (WT) lines. BvCPD increased the chlorophyll content and maximum photochemical efficiency and improved the photosynthetic characteristics of sugar beet leaves. Simultaneously, BvCPD increased the rate of sugar beet taproot respiration and ATP content by enhancing the activities of phosphoglycerate kinase, alcohol dehydrogenase, sucrose synthase, and sucrose synthase catabolism. Moreover, BvCPD induced changes in the sugar fraction content, which increased the sugar yield of a single plant. In addition, BvCPD promoted water absorption, nitrogen accumulation, and lignin/cellulose synthesis activities, facilitated by increased activities of phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, cellulose synthase, and protein serine/threonine phosphatases, providing the requisite energy and materials for sugar beet growth. These findings not only provide a new perspective for understanding the physiological mechanisms regulating the growth of sugar beets but also provide a theoretical basis for the future improvement of sugar beet varieties through molecular breeding techniques.