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MLife Jun 2024is a hyperthermophilic crenarchaeon that produces 1-butanol as an end product. A thermostable alcohol dehydrogenase (ADH) must be present in to act as the key enzyme...
is a hyperthermophilic crenarchaeon that produces 1-butanol as an end product. A thermostable alcohol dehydrogenase (ADH) must be present in to act as the key enzyme responsible for this production; however, the gene that encodes the ADH has not yet been identified. A novel ADH, HbADH2, was purified from a cell-free extract of , and its characteristics were determined. The gene that encodes HbADH2 was demonstrated to be and annotated as a hypothetical protein in . HbADH2 was found to be a primary-secondary ADH capable of using a wide range of substrates, including butyraldehyde and butanol. Butyraldehyde had the highest specificity constant, calculated as / , with and apparent values of 8.00 ± 0.22 s and 0.59 ± 0.07 mM, respectively. The apparent values for other substrates, including ethanol, 1-propanol, 2-propanol, butanol, acetaldehyde, propanal, and acetone, were 4.36 ± 0.42, 4.69 ± 0.41, 3.74 ± 0.46, 2.44 ± 0.30, 1.27 ± 0.18, 1.55 ± 0.20, and 0.68 ± 0.04 mM, respectively. The optimal pH values for catalyzing aldehyde reduction and alcohol oxidation were 6.0 and 9.0, respectively, while the optimal temperature was higher than 90°C due to the increase in enzymatic activity from 60°C to 90°C. Based on its substrate specificity, enzyme kinetics, and thermostability, HbADH2 may be the ADH that catalyzes the production of 1-butanol in . The putative conserved motif sites for NAD(P) and iron binding were identified by aligning HbADH2 with previously characterized Fe-containing ADHs.
PubMed: 38948144
DOI: 10.1002/mlf2.12126 -
MLife Jun 2024Sulfate-reducing microorganisms extensively contribute to the corrosion of ferrous metal infrastructure. There is substantial debate over their corrosion mechanisms. We...
Sulfate-reducing microorganisms extensively contribute to the corrosion of ferrous metal infrastructure. There is substantial debate over their corrosion mechanisms. We investigated Fe corrosion with , the sulfate reducer most often employed in corrosion studies. Cultures were grown with both lactate and Fe as potential electron donors to replicate the common environmental condition in which organic substrates help fuel the growth of corrosive microbes. Fe was corroded in cultures of a hydrogenase-deficient mutant with the 1:1 correspondence between Fe loss and H accumulation expected for Fe oxidation coupled to H reduction to H. This result and the extent of sulfate reduction indicated that was not capable of direct Fe-to-microbe electron transfer even though it was provided with a supplementary energy source in the presence of abundant ferrous sulfide. Corrosion in the hydrogenase-deficient mutant cultures was greater than in sterile controls, demonstrating that H removal was not necessary for the enhanced corrosion observed in the presence of microbes. The parental H-consuming strain corroded more Fe than the mutant strain, which could be attributed to H oxidation coupled to sulfate reduction, producing sulfide that further stimulated Fe oxidation. The results suggest that H consumption is not necessary for microbially enhanced corrosion, but H oxidation can indirectly promote corrosion by increasing sulfide generation from sulfate reduction. The finding that was incapable of direct electron uptake from Fe reaffirms that direct metal-to-microbe electron transfer has yet to be rigorously described in sulfate-reducing microbes.
PubMed: 38948142
DOI: 10.1002/mlf2.12133 -
IScience Jun 2024Sulfate-reducing bacteria (SRB) are ubiquitously distributed across various biospheres and play key roles in global sulfur and carbon cycles. However, few deep-sea SRB...
Sulfate-reducing bacteria (SRB) are ubiquitously distributed across various biospheres and play key roles in global sulfur and carbon cycles. However, few deep-sea SRB have been cultivated and studied , limiting our understanding of the true metabolism of deep-sea SRB. Here, we firstly clarified the high abundance of SRB in deep-sea sediments and successfully isolated a sulfate-reducing bacterium (zrk46) from a cold seep sediment. Our genomic, physiological, and phylogenetic analyses indicate that strain zrk46 is a novel species, which we propose as . We found that supplementation with sulfate, thiosulfate, or sulfite promoted strain zrk46 growth by facilitating energy production through the dissimilatory sulfate reduction, which was coupled to the oxidation of organic matter in both laboratory and deep-sea conditions. Moreover, metatranscriptomic results confirmed that other deep-sea SRB also performed the dissimilatory sulfate reduction, strongly suggesting that SRB may play undocumented roles in deep-sea sulfur cycling.
PubMed: 38947506
DOI: 10.1016/j.isci.2024.110095 -
World Journal of Gastroenterology Jun 2024In this editorial we comment on the article published in a recent issue of the . Acute liver failure (ALF) is a critical condition characterized by rapid hepatocellular... (Review)
Review
In this editorial we comment on the article published in a recent issue of the . Acute liver failure (ALF) is a critical condition characterized by rapid hepatocellular injury and organ dysfunction, and it often necessitates liver transplant to ensure patient survival. Recent research has elucidated the involvement of distinct cell death pathways, namely ferroptosis and pyroptosis, in the pathogenesis of ALF. Ferroptosis is driven by iron-dependent lipid peroxidation, whereas pyroptosis is an inflammatory form of cell death; both pathways contribute to hepatocyte death and exacerbate tissue damage. This comprehensive review explores the interplay between ferroptosis and pyroptosis in ALF, highlighting the role of key regulators such as silent information regulator sirtuin 1. Insights from clinical and preclinical studies provide valuable perspectives on the dysregulation of cell death pathways in ALF and the therapeutic potential of targeting these pathways. Collaboration across multiple disciplines is essential for translating the experimental insights into effective treatments for this life-threatening condition.
Topics: Humans; Liver Failure, Acute; Ferroptosis; Pyroptosis; Hepatocytes; Animals; Sirtuin 1; Signal Transduction; Liver; Lipid Peroxidation; Liver Transplantation; Iron
PubMed: 38946877
DOI: 10.3748/wjg.v30.i23.2931 -
Physiologia Plantarum 2024Plants can experience a variety of environmental stresses that significantly impact their fitness and survival. Additionally, biotic stress can harm agriculture, leading... (Review)
Review
Plants can experience a variety of environmental stresses that significantly impact their fitness and survival. Additionally, biotic stress can harm agriculture, leading to reduced crop yields and economic losses worldwide. As a result, plants have developed defense strategies to combat potential invaders. These strategies involve regulating redox homeostasis. Several studies have documented the positive role of plant antioxidants, including Ascorbate (Asc), under biotic stress conditions. Asc is a multifaceted antioxidant that scavenges ROS, acts as a co-factor for different enzymes, regulates gene expression, and facilitates iron transport. However, little attention has been given to Asc and its transport, regulatory effects, interplay with phytohormones, and involvement in defense processes under biotic stress. Asc interacts with other components of the redox system and phytohormones to activate various defense responses that reduce the growth of plant pathogens and promote plant growth and development under biotic stress conditions. Scientific reports indicate that Asc can significantly contribute to plant resistance against biotic stress through mutual interactions with components of the redox and hormonal systems. This review focuses on the role of Asc in enhancing plant resistance against pathogens. Further research is necessary to gain a more comprehensive understanding of the molecular and cellular regulatory processes involved.
Topics: Plant Growth Regulators; Stress, Physiological; Ascorbic Acid; Plants; Antioxidants; Oxidation-Reduction; Gene Expression Regulation, Plant; Plant Diseases
PubMed: 38946634
DOI: 10.1111/ppl.14388 -
Chemistry, An Asian Journal Jul 2024Iron-nitrogen functionalized graphene has emerged as a promising cathode host for rechargeable lithium-sulfur batteries (RLSBs) due to its affordability and enhanced...
Iron-nitrogen functionalized graphene has emerged as a promising cathode host for rechargeable lithium-sulfur batteries (RLSBs) due to its affordability and enhanced battery performance. To optimize its catalytical efficiency, we propose a novel approach involving coordination engineering. Our investigation spans a plethora of catalysts with varied coordination environments, focusing on elements B, C, N and O. We revealed that Fe-C4 and Fe-B2C2-h are particularly effective for promoting Li2S oxidation, whereas Fe-N4 excels in catalyzing the sulfur reduction reaction (SRR). Importantly, our study identified specific descriptors - namely, the Integrated Crystal Orbital Hamilton Population (ICOHP) and the bond length between Fe and S in Li2S adsorbed state - as the most effective predictive descriptors for Li2S oxidation barriers. Meanwhile, Li2S adsorption energy emerges as a reliable descriptor for assessing the SRR barrier. These identified descriptors are expected to be instrumental in rapidly identifying promising cathode hosts across various metal-centered systems with diverse coordination environments. Our findings not only offer valuable insights into the role of coordination environment, but also present an effective path for rapidly identifying high performance catalysts for RLSBs, enabling the acceleration of advanced RLSBs development.
PubMed: 38946437
DOI: 10.1002/asia.202400199 -
Journal of Cellular Physiology Jun 2024Skeletal muscle injury affects the quality of life in many pathologies, including volumetric muscle loss, contusion injury, and aging. We hypothesized that the...
Skeletal muscle injury affects the quality of life in many pathologies, including volumetric muscle loss, contusion injury, and aging. We hypothesized that the nicotinamide phosphoribosyltransferase (Nampt) activator P7C3 improves muscle repair following injury. In the present study, we tested the effect of P7C3 (1-anilino-3-(3,6-dibromocarbazol-9-yl) propan-2-ol) on chemically induced muscle injury. Muscle injury was induced by injecting 50 µL 1.2% barium chloride (BaCl) into the tibialis anterior (TA) muscle in C57Bl/6J wild-type male mice. Mice were then treated with either 10 mg/kg body weight of P7C3 or Vehicle intraperitoneally for 7 days and assessed for histological, biochemical, and molecular changes. In the present study, we show that the acute BaCl-induced TA muscle injury was robust and the P7C3-treated mice displayed a significant increase in the total number of myonuclei and blood vessels, and decreased serum CK activity compared with vehicle-treated mice. The specificity of P7C3 was evaluated using Nampt mice, which did not display any significant difference in muscle repair capacity among treated groups. RNA-sequencing analysis of the injured TA muscles displayed 368 and 212 genes to be exclusively expressed in P7C3 and Veh-treated mice, respectively. There was an increase in the expression of genes involved in cellular processes, inflammatory response, angiogenesis, and muscle development in P7C3 versus Veh-treated mice. Conversely, there is a decrease in muscle structure and function, myeloid cell differentiation, glutathione, and oxidation-reduction, drug metabolism, and circadian rhythm signaling pathways. Chromatin immunoprecipitation-quantitative polymerase chain reaction (qPCR) and reverse transcription-qPCR analyses identified increased Pax7, Myf5, MyoD, and Myogenin expression in P7C3-treated mice. Increased histone lysine (H3K) methylation and acetylation were observed in P7C3-treated mice, with significant upregulation in inflammatory markers. Moreover, P7C3 treatment significantly increased the myotube fusion index in the BaCl-injured human skeletal muscle in vitro. P7C3 also inhibited the lipopolysaccharide-induced inflammatory response and mitochondrial membrane potential of RAW 264.7 macrophage cells. Overall, we demonstrate that P7C3 activates muscle stem cells and enhances muscle injury repair with increased angiogenesis.
PubMed: 38946152
DOI: 10.1002/jcp.31346 -
Inorganic Chemistry Jun 2024Constructing the plasmonic metal/semiconductor heterostructure with a suitable Schottky barrier height (SBH) and the sufficiently reliable active sites is of importance...
Constructing the plasmonic metal/semiconductor heterostructure with a suitable Schottky barrier height (SBH) and the sufficiently reliable active sites is of importance to achieve highly efficient and selective photocatalytic CO reduction into hydrocarbon fuels. Herein, we report Au/sulfur vacancy-rich ZnInS (Au/VR-ZIS) hierarchical photocatalysts, fabricated via in situ photodepositing Au nanoparticles (NPs) onto the nanosheet self-assembled ZnInS (ZIS) micrometer flowers (MFs) with rich sulfur vacancies (V). Density functional theory (DFT) calculations confirm that for the Au/VR-ZIS system, the Au NPs serve as the reaction sites for HO oxidation, and the VR-ZIS MFs serve as those for CO reduction. The rich V in the Au/VR-ZIS hybrid can reduce its SBH so as to boost more hot electrons in the Au NPs across its Schottky barrier and then inject into the conduction band (CB) of the VR-ZIS MFs. In addition, V can also act as the electron sink to trap the photogenerated electrons, retarding the recombination of photogenerated carriers. The two merits effectively enhance the photogenerated electron density in the surface of VR-ZIS MFs, availing CO photoreduction. In addition, the introduction of rich V in the Au/VR-ZIS hybrid can offer more active sites, benefiting the CO adsorption and accelerating the desorption of CO* from the surface of the photocatalyst. Therefore, under visible light illumination with no sacrificial reagent, the optimum photocatalyst (Au/VR-ZIS-0.4) presents the enhanced and selective CO photoreduction into CO (8.15 μmol gh and near 100%), which are superior to those of most of ZIS-based and plasmon-based photocatalysts. The photocatalytic activity is about 40.0-fold as high as that of the Vs-poor-ZIS (VP-ZIS) MFs. This work contributes a viable strategy for designing highly efficient plasmonic photocatalysts by using the synergism of the anion vacancies and the optimized SBH induced by them.
PubMed: 38946108
DOI: 10.1021/acs.inorgchem.4c02376 -
Journal of Oleo Science 2024In this study, we evaluated the cancer cell killing activity of koji mold-derived extracts using several solvents. The koji mold lipid extract (KML) exhibited potent...
Koji Mold-derived Lipids Disrupt the Intracellular Redox State by Decreasing the GPx4 and Intracellular Glutathione Levels, Promoting Membrane Lipid Peroxidation, and Inducing Ferroptosis in HL-60 Cells.
In this study, we evaluated the cancer cell killing activity of koji mold-derived extracts using several solvents. The koji mold lipid extract (KML) exhibited potent cytotoxicity against a human leukemia cell line. Fractionation of the KML via silica gel chromatography revealed the presence of active components in fraction (Fr.) 6. Cytotoxic effects of Fr. 6 were inhibited by the ferroptosis inhibitors, ferrostatin-1 and SRS11-92, and the iron chelator, deferoxamine. Interestingly, ferroptosis inhibitors failed to prevent the KML-induced cell death. Fr. 6 decreased the expression of glutathione peroxidase 4 (GPx4) and increased the level of peroxidized plasma membrane lipids. Furthermore, Fr. 6 decreased the intracellular glutathione levels. Overall, our results suggest that Fr. 6 included in KML induces ferroptosis in HL-60 cells.
Topics: Humans; HL-60 Cells; Phospholipid Hydroperoxide Glutathione Peroxidase; Ferroptosis; Lipid Peroxidation; Glutathione; Oxidation-Reduction; Deferoxamine; Cyclohexylamines; Lipids; Phenylenediamines; Membrane Lipids; Iron Chelating Agents
PubMed: 38945927
DOI: 10.5650/jos.ess24043 -
Journal of Oleo Science 2024This comprehensive review offers a chemical analysis of cutting fluids, delving into both their formulation and deformulation processes. The study covers a wide spectrum... (Review)
Review
This comprehensive review offers a chemical analysis of cutting fluids, delving into both their formulation and deformulation processes. The study covers a wide spectrum of cutting fluid formulations, ranging from simple compositions predominantly comprising oils, whether mineral or vegetable, to emulsions. The latter involves the integration of surfactants, encompassing both nonionic and anionic types, along with a diverse array of additives. Concerning oils, the current trend leans towards the use of vegetable oils instead of mineral oils for environmental reasons. As vegetable oils are more prone to oxidation, chemical alterations, the addition of antioxidant may be necessary. The chemical aspects of the different compounds are scrutinized, in order to understand the role of each component and its impact on the fluid's lubricating, cooling, anti-wear, and anti-corrosion properties. Furthermore, the review explores the deformulation methodologies employed to dissect cutting fluids. This process involves a two-step approach: separating the aqueous and organic phases of the emulsions by physical or chemical treatments, and subsequently conducting a detailed analysis of each to identify the compounds. Several analytical techniques, including spectrometric or chromatographic, can be employed simultaneously to reveal the chemical structures of samples. This review aims to contribute to the improvement of waste treatment stemming from cutting fluids. By gathering extensive information about the formulation, deformulation, and chemistry of the ingredients, there is a potential to enhance the waste management and disposal effectively.
Topics: Emulsions; Surface-Active Agents; Plant Oils; Mineral Oil; Antioxidants; Oxidation-Reduction; Lubrication; Lubricants; Chemical Phenomena
PubMed: 38945922
DOI: 10.5650/jos.ess24068