Mapping the evolution of acne research based on 100 top-cited articles: A bibliometric analysis of trends and hotspots from 2014 to 2023.

BACKGROUND: Acne is a prevalent inflammatory condition of the pilosebaceous unit, which seriously affects the appearance and mental health of patients. Bibliometrics is the statistical analysis of academic literature in a certain field. We aimed to characterize the 100 most cited articles on acne from a bibliometric perspective, as well as explore the frontier hotspots and trends of acne. METHODS: A search was conducted on the Web of Science database on August 8, 2023. we employed the terms "acne," "acne Vulgaris," and "common acne" in our search. The top 100 articles with the most citations throughout the time frame of 2014 to 2023 were discovered and assessed. The visualization study was carried out using bibliometric tools such as CiteSpace 6.2.R4, VOSviewer 1.6.18, and MapChart. RESULTS: The top 100 most cited articles were published between 2014 and 2021, originated from a diverse range of 48 countries, with a predominant focus on the United States of America (USA) and Germany. The top 100 papers were cited between 50 and 712 times. Dreno B, from Nantes University, was the most frequently nominated author. With 12 papers, the Journal of the European Academy of Dermatology and Venereology contributed the most to the top 100 list. Alongside the term "acne", the following terms or phrases were observed frequency in the top 100 articles, Cutibacterium acnes, sebaceous, western diet, antibiotic resistance, staphylococcus-epidermidis, insulinlike growth factor 1, benzoyl peroxide, and polyunsaturated fatty acids. Alongside the term "acne", terms or phrases such as Cutibacterium acnes, sebaceous, western diet, antibiotic resistance, staphylococcus-epidermidis, insulinlike growth factor 1, benzoyl peroxide, and polyunsaturated fatty acids, etc also have a high frequency in the top 100 articles. CONCLUSION: This analysis summarizes the shifting trends of acne research over the last decades. Research on acne is currently flourishing. The related pathogenesis and therapeutic strategies have been the focus of current research and developmental trends in future research.

Biodegradation of phthalic acid esters (PAEs) by Janthinobacterium sp. strain E1 under stress conditions.

Phthalates esters (PAEs) are a kind of polymeric material additives widely been added into plastics to improve products' flexibility. It can easily cause environmental pollution which are hazards to public health. In this study, we isolated an efficient PAEs degrading strain, Janthinobacterium sp. E1, and determined its degradation effect of di-2-ethylhexyl phthalate (DEHP) under stress conditions. Strain E1 showed an obvious advantage in pollutants degradation under various environmental stress conditions. Degradation halo clearly occurred around the colony of strain E1 on agar plate supplemented with triglyceride. Strain E1's esterase is a constitutively expressed intracellular enzyme. The esterase purified from strain E1 showed a higher catalytic effect on short-chain PAEs than long-chain PAEs. The input of DEHP, DBP (dibutyl phthalate) and DMP (dimethyl phthalate) into the tested soil did not change the species composition of soil prokaryotic community, but altered the dominant species in specific environmental conditions. And the community diversity and richness decreased to a certain extent. However, the diversity and richness of the microbial community were improved after the contaminated soil was treated with the strain E1. Our results also suggested that strain E1 exhibited a tremendous potential in environmental bioremediation in the real environment, which provides a new insight into the elimination of the pollutants contamination in the urban environment.

Knowledge Mapping and Research Hotspots of Generalized Pustular Psoriasis: A Bibliometric Analysis from 2003 to 2023.

Background: Generalised pustular psoriasis (GPP) is a chronic inflammatory skin disease. We aimed to visualize the research hotspots and trends of GPP using bibliometric analysis to enhance our comprehension of the future advancements in both basic science and clinical research. Methods: Relevant publications from July 2003 to July 2023 were obtained from the Web of Science Core Collection on July 12, 2023. The analysis of countries, institutions, authors, references, and keywords associated with this subject was conducted through the utilisation of CiteSpace 6.2.R4, VOSviewer 1.6.18, and Microsoft Excel 2019. Results: A total of 578 papers were analyzed, authored by 2758 researchers from 191 countries/regions and 1868 institutions, published in 174 academic journals. There was an overall upward trajectory in the volume of annual publications, accompanied by a gradual intensification of research interest in GPP. The United States, UDICE-French Research Universities, and Akiyama M of Nagoya University were the most productive and influential country, institution, and author, respectively. The Journal of Dermatology ranked first with the highest publications, and the Journal of the American Academy of Dermatology received the most citations. High-frequency keywords included "generalized pustular psoriasis", "psoriasis, interleukin-36", "plaque psoriasis", "skin-disease", and "antagonist deficiency". Recent research focuses have included "safety", "secukinumab", "spesolimab", "ap1s3 mutations", and "interleukin-36". Burst detection analysis of keywords showed that "moderate", "ixekizumab treatment", "mutations", "efficacy", and "safety" are current research frontiers in this field. Conclusion: This bibliometric analysis delineated the landmark publications in GPP that have defined current research hotspots and development trends, notably the applications, efficacy, and safety of biological agents. Future research endeavors are warranted to explore other biological therapeutic options for both acute GPP and the long-term management of chronic GPP.

Genomics and transcriptomics of the Chinese mitten crabs (Eriocheir sinensis).

To gain a deeper understanding of the genetic factors influencing the growth and development of Eriocheir sinensis, a well-known species of hairy crab found in Yangcheng Lake, this study focused on the de novo genome and full-length transcriptome information of the selected subjects. Specifically, Yangcheng Lake hairy crabs were chosen as the experimental samples. Initially, a genome analysis was performed, resulting in the identification of gene fragments with a combined length of 1266,092,319 bp. Subsequently, a transcriptome analysis was conducted on a mixture of tissues from four different sites, namely muscle, brain, eye, and heart, to further investigate the genetic characteristics at the transcriptome level. The Pacific Biosciences (Pacio) single-molecule real-time sequencing system generated a total of 36.93 G sub-fragments and 175,90041 effective inserts. This research contributes to the indirect comprehension of genetic variations underlying individual traits. Furthermore, a comparison of the obtained data with relevant literature emphasizes the advantages of this study and establishes a basis for further investigations on the Chinese mitten crab.

In Situ Structural Observation of a Substrate- and Peroxide-Bound High-Spin Ferric-Hydroperoxo Intermediate in the P450 Enzyme CYP121.

The P450 enzyme CYP121 from Mycobacterium tuberculosis catalyzes a carbon-carbon (C-C) bond coupling cyclization of the dityrosine substrate containing a diketopiperazine ring, cyclo(l-tyrosine-l-tyrosine) (cYY). An unusual high-spin (S = 5/2) ferric intermediate maximizes its population in less than 5 ms in the rapid freeze-quenching study of CYP121 during the shunt reaction with peracetic acid or hydrogen peroxide in acetic acid solution. We show that this intermediate can also be observed in the crystalline state by EPR spectroscopy. By developing an on-demand-rapid-mixing method for time-resolved serial femtosecond crystallography with X-ray free-electron laser (tr-SFX-XFEL) technology covering the millisecond time domain and without freezing, we structurally monitored the reaction in situ at room temperature. After a 200 ms peracetic acid reaction with the cocrystallized enzyme-substrate microcrystal slurry, a ferric-hydroperoxo intermediate is observed, and its structure is determined at 1.85 Å resolution. The structure shows a hydroperoxyl ligand between the heme and the native substrate, cYY. The oxygen atoms of the hydroperoxo are 2.5 and 3.2 Å from the iron ion. The end-on binding ligand adopts a near-side-on geometry and is weakly associated with the iron ion, causing the unusual high-spin state. This compound 0 intermediate, spectroscopically and structurally observed during the catalytic shunt pathway, reveals a unique binding mode that deviates from the end-on compound 0 intermediates in other heme enzymes. The hydroperoxyl ligand is only 2.9 Å from the bound cYY, suggesting an active oxidant role of the intermediate for direct substrate oxidation in the nonhydroxylation C-C bond coupling chemistry.

Mechanism of safener mefenpyr-diethyl biodegradation by a newly isolated Chryseobacterium sp. B6 from wastewater sludge and application in co-contaminated soil.

Safener mefenpyr-diethyl (MFD) was applied to cereal crops along with herbicides to improve herbicide selectivity for crops and weeds. However, the degradation mechanism of MFD in the environment remains unclear. One MFD-degrading bacterium, Chryseobacterium sp. B6, was isolated from activated sludge. According to Box-Behnken's optimal design, the degradation efficiency of MFD can reach 92% under conditions of pH 7.5, 30 °C, and a MFD concentration of 184 mg L-1. The degradation half-life experiment showed that a high concentration of MFD (300 mg L-1) inhibited the degradation ability of strain B6. Additionally, strain B6 was resistant to Ba2+, Cr3+, Li+, Zn2+, and Cu2+. The MFD degradation products of strain B6 were detected by GC/MS and its degradation pathway was proposed. MFD was first hydrolyzed by a hydrolase to an intermediate (RS)-1-(2,4-dichlorophenyl)-5-methyl-2-pyrazoline-5-carboxylic acid ethyl ester-3-carboxylic acid, and then further degraded by a decarboxylase to form the intermediate (RS)-1-(2,4-dichlorophenyl)-5-methyl-2-pyrazoline-5-carboxylic acid ethyl ester, finally, it is completely degraded by strain B6. Furthermore, strain B6 could effectively remove MFD from MFD-contaminated soil, and the half-life of MFD was also significantly reduced in MFD and Cu2+ co-contaminated soil after inoculating strain B6. To our knowledge, strain B6 was the first strain reported to degrade safener MFD, and this study provides a valuable candidate to remediate the co-contaminated soil with MFD and Cu2+.

Identification of PANoptosis-related biomarkers and immune infiltration characteristics in psoriasis.

BACKGROUND: PANoptosis may play a vital role in psoriasis. We investigated the relationship between PANoptosis in psoriasis. METHODS: Genes information was mainly obtained from GeneCards and the gene expression omnibus database. Genefunctions identification was based on gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Gene set enrichment analysis was used to identify enriched signaling pathways in psoriasis. We constructed PPI networks using the search tool for the retrieval of interacting genes database and Cytoscape and explored mRNA-miRNA, mRNA-TF, and mRNA-drug interaction networks. Receiver operating characteristic curves were performed to screen potential biomarkers among these hub genes. Immune cell infiltration was analyzed using the Pearson algorithm, and the correlation between immune-cell abundance and PANoptosis-related differentially expressed gene (PDGs) was investigated. RESULTS: We identified 10 PDGs, which were mainly involved in pyroptosis, cytokine-mediated signaling pathways, Salmonella infection and NOD-like receptor signaling pathway. The activated pathways were mostly proinflammatory and immunoregulatory pathways between immune cells. BAK1, CASP4, IL18, and IRF1 were identified as hub genes in the mRNA-miRNA network, and BAK1, IRF1, and PYCARD were hub genes in the mRNA-TF network. CASP1 was found to be the most targeted gene by drugs or molecular compounds. We found PDGs were positively associated with proinflammatory immune cell infiltration and negatively associated with anti-inflammatory or regulatory immune cells. CONCLUSION: We confirmed the role of PANoptosis in psoriasis for the first time and predicted hub genes and immune characteristics, which provides new ideas for further investigation of psoriasis on pathogenic mechanisms and therapeutic strategies.

Simultaneous separation and detection of nine kynurenine pathway metabolites by reversed-phase liquid chromatography-mass spectrometry: Quantitation of inflammation in human cerebrospinal fluid and plasma.

BACKGROUND: The kynurenine pathway (KP) generates eight tryptophan (TRP) metabolites collectively called kynurenines, which have gained enormous interest in clinical research. The importance of KP for different disease states calls for developing a low-cost and high-throughput chromatography-mass spectrometry method to evaluate the potential of different kynurenines. Simultaneous separation of TRP and its eight metabolites is challenging because they have substantial polarity differences (log P = -2.5 to +1.3). RESULTS: A low-cost, reversed-phase LC-MS/MS method based on polarity partitioning was established to simultaneously separate and quantitate all nine kynurenine pathway metabolites (KPMs) in a single run for the first time in the open literature. Based on stationary phase screening and ternary mobile phase optimization strategy, high polarity KPMs were retained while medium and low polarity KPMs were eluted in a shorter time. After method validation, we demonstrated the applicability of this LC/MS/MS method by quantitative measurement of all nine KPM in cerebrospinal fluid (CSF) and plasma among two groups of human subjects diagnosed with depression. Furthermore, we measured the differential KPMs in these two groups of low and high inflammation and correlated the results with CRP or TNF-α markers for depression. SIGNIFICANCE: Our proposed LC-MS/MS provides a new metabolite assay that can be easily applied in various clinical applications to simultaneously quantify multiple biomarkers in KP dysfunction.

Icariin restrains NLRP3 inflammasome-mediated Th2 immune responses and ameliorates atopic dermatitis through modulating a novel lncRNA MALAT1/miR-124-3p axis.

CONTEXT: Atopic dermatitis (AD) is a common inflammatory skin disease characterized with hyperactivation of type 2 T helper (Th2) immune responses. Icariin is a flavonoid glucoside with anti-inflammatory activities, which has been used to treat multiple diseases. OBJECTIVE: The present study investigates the underlying mechanisms by which icariin regulates Th2 responses and AD development. MATERIALS AND METHODS: BALB/c mice were induced by DNFB to establish AD models, and injected with or without 10 mg/kg icariin for 2 weeks (i.p., daily). CD4+T cells were induced by Th2 condition to simulate AD in vitro, and also treated with or without 100 µM icariin. RESULTS: Icariin ameliorated AD-like skin lesion, manifested as a significant decrease in dermatitis scores (from 8.00 ± 1.00 to 3.67 ± 0.58), serum IgE levels (from 3119.15 ± 241.81 to 948.55 ± 182.51 ng/mL), epidermal thickness (from 93.86 ± 4.61 to 42.67 ± 2.48 µm) and infiltration of mast cells (from 60.67 ± 3.21 cells to 36.00 ± 2.65 cells). Also, icariin inactivated NLRP3 inflammasome, inhibited Th2 skewing, reduced lncRNA MALAT1 expression, but elevated miR-124-3p expression in vivo and in vitro. MALAT1 increased NLRP3 expression through targeting miR-124-3p. Knockdown of MALAT1 repressed NLRP3 inflammasome activation and mitigated Th1/Th2 imbalance in Th2-conditioned CD4+T cells, whereas both MALAT1 overexpression and miR-124-3p inhibition ablated the inhibitory effects of icariin on Th2 immune responses. DISCUSSION AND CONCLUSIONS: The findings further improve our understanding of the mechanism by which icariin affects AD progression, and highlights the potential of icariin in the treatment of AD.

Structural and spectroscopic characterization of RufO indicates a new biological role in rufomycin biosynthesis.

Rufomycins constitute a class of cyclic heptapeptides isolated from actinomycetes. They are secondary metabolites that show promising treatment against Mycobacterium tuberculosis infections by inhibiting a novel drug target. Several nonproteinogenic amino acids are integrated into rufomycins, including a conserved 3-nitro-tyrosine. RufO, a cytochrome P450 (CYP)-like enzyme, was proposed to catalyze the formation of 3-nitro-tyrosine in the presence of O2 and NO. To define its biological function, the interaction between RufO and the proposed substrate tyrosine is investigated using various spectroscopic methods that are sensitive to the structural change of a heme center. However, a low- to high-spin state transition and a dramatic increase in the redox potential that are commonly found in CYPs upon ligand binding have not been observed. Furthermore, a 1.89-Å crystal structure of RufO shows that the enzyme has flexible surface regions, a wide-open substrate access tunnel, and the heme center is largely exposed to solvent. Comparison with a closely related nitrating CYP reveals a spacious and hydrophobic distal pocket in RufO, which is incapable of stabilizing a free amino acid. Molecular docking validates the experimental data and proposes a possible substrate. Collectively, our results disfavor tyrosine as the substrate of RufO and point to the possibility that the nitration occurs during or after the assembly of the peptides. This study indicates a new function of the unique nitrating enzyme and provides insights into the biosynthesis of nonribosomal peptides.

TMEM132A regulates mouse hindgut morphogenesis and caudal development.

Caudal developmental defects, including caudal regression, caudal dysgenesis and sirenomelia, are devastating conditions affecting the skeletal, nervous, digestive, reproductive and excretory systems. Defects in mesodermal migration and blood supply to the caudal region have been identified as possible causes of caudal developmental defects, but neither satisfactorily explains the structural malformations in all three germ layers. Here, we describe caudal developmental defects in transmembrane protein 132a (Tmem132a) mutant mice, including skeletal, posterior neural tube closure, genitourinary tract and hindgut defects. We show that, in Tmem132a mutant embryos, visceral endoderm fails to be excluded from the medial region of early hindgut, leading directly to the loss or malformation of cloaca-derived genitourinary and gastrointestinal structures, and indirectly to the neural tube and kidney/ureter defects. We find that TMEM132A mediates intercellular interaction, and physically interacts with planar cell polarity (PCP) regulators CELSR1 and FZD6. Genetically, Tmem132a regulates neural tube closure synergistically with another PCP regulator Vangl2. In summary, we have identified Tmem132a as a new regulator of PCP, and hindgut malformation as the underlying cause of developmental defects in multiple caudal structures.

Structural insights into the half-of-sites reactivity in homodimeric and homotetrameric metalloenzymes.

Half-of-sites reactivity in many homodimeric and homotetrameric metalloenzymes has been known for half a century, yet its benefit remains poorly understood. A recently reported cryo-electron microscopy structure has given some clues on the less optimized reactivity of Escherichia coli ribonucleotide reductase with an asymmetric association of α2ß2 subunits during catalysis. Moreover, nonequivalence of enzyme active sites has been reported in many other enzymes, possibly as a means of regulation. They are often induced by substrate binding or caused by a critical component introduced from a neighboring subunit in response to substrate loadings, such as in prostaglandin endoperoxide H synthase, cytidine triphosphate synthase, glyoxalase, tryptophan dioxygenase, and several decarboxylases or dehydrogenases. Overall, half-of-sites reactivity is likely not an act of wasting resources but rather a method devised in nature to accommodate catalytic or regulatory needs.

Kynurenine Pathway Regulation at Its Critical Junctions with Fluctuation of Tryptophan.

The kynurenine pathway (KP) is the primary route for the catabolism of the essential amino acid tryptophan. The central KP metabolites are neurologically active molecules or biosynthetic precursors to critical molecules, such as NAD+. Within this pathway are three enzymes of interest, HAO, ACMSD, and AMSDH, whose substrates and/or products can spontaneously cyclize to form side products such as quinolinic acid (QA or QUIN) and picolinic acid. Due to their unstable nature for spontaneous autocyclization, it might be expected that the levels of these side products would be dependent on tryptophan intake; however, this is not the case in healthy individuals. On top of that, the regulatory mechanisms of the KP remain unknown, even after a deeper understanding of the structure and mechanism of the enzymes that handle these unstable KP metabolic intermediates. Thus, the question arises, how do these enzymes compete with the autocyclization of their substrates, especially amidst increased tryptophan levels? Here, we propose the formation of a transient enzyme complex as a regulatory mechanism for metabolite distribution between enzymatic and non-enzymatic routes during periods of increased metabolic intake. Amid high levels of tryptophan, HAO, ACMSD, and AMSDH may bind together, forming a tunnel to shuttle the metabolites through each enzyme, consequently regulating the autocyclization of their products. Though further research is required to establish the formation of transient complexation as a solution to the regulatory mysteries of the KP, our docking model studies support this new hypothesis.

Quantitation of tryptophan and kynurenine in human plasma using 4-vinylphenylboronic acid column by capillary electrochromatography coupled with mass spectrometry.

Tryptophan (TRP) is an essential amino acid catabolized mainly through the kynurenine pathway, and part of it is catabolized in the brain. The abnormal depletion of TRP and production of kynurenine (KYN) by two enzymes, tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO), have been linked to various neurological diseases. The ratio of TRP/KYN in plasma is a valuable measure for IDO/TDO activity and the prognosis of disease conditions. The 4-vinylphenylboronic acid (4-VPBA) was evaluated as a novel stationary phase for OT-CEC-MS/MS. TRP, KYN, and 3-hydroxykynurenine were separated using optimum conditions of 15 mM (NH4 )2 CO3 at pH 8 as a background electrolyte and 25 kV separation voltage on a 90 cm column. The usefulness of the 4-VPBA column for simple, fast, repeatable, and sensitive CEC-ESI-MS/MS application was demonstrated for the quantitation of TRP and KYN in the plasma of healthy human subjects and neuroinflammation subjects. The plasma sample was extracted on a zirconia-based ion-exchange cartridge for simultaneous protein precipitation and phospholipid removal. The method of standard addition, in combination with the internal standards approach, was used to prepare the calibration curve to overcome matrix matching and eliminate procedural errors. The developed quantitation method was validated according to FDA guidelines for sensitivity, accuracy, precision, and extraction recovery. The measured plasma level of TRP and KYN in healthy humans is aligned with the human metabolome database for the same two metabolites.

Deficiency of the Planar Cell Polarity Protein Intu Delays Kidney Repair and Suppresses Renal Fibrosis after Acute Kidney Injury.

Planar cell polarity (PCP), a process of coordinated alignment of cell polarity across the tissue plane, may contribute to the repair of renal tubules after kidney injury. Intu is a key effector protein of PCP. Herein, conditional knockout (KO) mouse models that ablate Intu specifically from kidney tubules (Intu KO) were established. Intu KO mice and wild-type littermates were subjected to unilateral renal ischemia/reperfusion injury (IRI) or unilateral ureteral obstruction. Kidney repair was evaluated by histologic, biochemical, and immunohistochemical analyses. In vitro, scratch wound healing was examined in Intu-knockdown and control renal tubular cells. Ablation of Intu in renal tubules delayed kidney repair and ameliorated renal fibrosis after renal IRI. Intu KO mice had less renal fibrosis during unilateral ureteral obstruction. Mechanistically, Intu KO kidneys had less senescence but higher levels of cell proliferation and apoptosis during kidney repair after renal IRI. In vitro, Intu knockdown suppressed scratch wound healing in renal tubular cells, accompanied by the abnormality of centrosome orientation. Together, the results provide the first evidence for the involvement of PCP in tubular repair after kidney injury, shedding light on new strategies for improving kidney repair and recovery.

High-quality genomes reveal significant genetic divergence and cryptic speciation in the model organism Folsomia candida (collembola).

The collembolan Folsomia candida Willem, 1902, is widely distributed throughout the world and has been frequently used as a test organism in soil ecology and ecotoxicology studies. However, it is questioned as an ideal "standard" because of differences in reproductive modes and cryptic genetic diversity between strains from various geographical origins. In this study, we obtained two high-quality chromosome-level genomes of F. candida, for a parthenogenetic strain (named FCDK, 219.08 Mb, 25,139 protein-coding genes) and a sexual strain (named FCSH, 153.09 Mb, 21,609 protein-coding genes), reannotated the genome of the parthenogenetic strain reported by Faddeeva-Vakhrusheva et al. in 2017 (named FCBL, 221.7 Mb, 25,980 protein-coding genes) and conducted comparative genomic analyses of the three strains. High genome similarities between FCDK and FCBL based on synteny, genome architecture, mitochondrial and nuclear gene sequences suggest that they are conspecific. The seven chromosomes of FCDK are each 25%-54% larger than the corresponding chromosomes of FCSH, showing obvious repetitive element expansions and large-scale inversions and translocations but no whole-genome duplication. The strain-specific genes, expanded gene families and genes in nonsyntenic chromosomal regions identified in FCDK are highly related to the broader environmental adaptation of parthenogenetic strains. In addition, FCDK has fewer strain-specific microRNAs than FCSH, and their mitochondrial and nuclear genes have diverged greatly. In conclusion, FCDK/FCBL and FCSH have accumulated independent genetic changes and evolved into distinct species after 10 million years ago. Our work provides important genomic resources for studying the mechanisms of rapidly cryptic speciation and soil arthropod adaptation to soil ecosystems.

Leaching valuable metals from spent lithium-ion batteries using the reducing agent methanol.

When considering resource shortages and environmental pressures, salvaging valuable metals from the cathode materials of spent lithium-ion batteries (LIBs) is a very promising strategy to realize the green and sustainable development of batteries. The reductive acid leaching of valuable metals from cathode materials using methanol as a reducing agent was studied. The results show that the leaching efficiencies of Co and Li are 99% under optimal leaching conditions. The leaching kinetics of cathode materials in a H2SO4-methanol system indicate that the leaching of Co and Li is controlled by diffusion, with activation energies of 69.98 and 10.78 kJ/mol, respectively. Detailed analysis of the leaching reaction mechanism indicates that methanol is ultimately transformed into formic acid through a two-step process to further enhance leaching. No side reactions occur during leaching. Methanol can be a sustainable alternative for the reductive acid leaching of valuable metals from spent LIBs due to its high efficiency, application maturity, environmental friendliness, and low cost.

Revealing the driving synergistic degradation mechanism of Rhodococcus sp. B2 on the bioremediation of pretilachlor-contaminated soil.

The pretilachlor has been widely used worldwide and has contaminated the environment for many years. The environmental fate of pretilachlor and its residues removal from the contaminated environment have attracted great concern. Reportedly, pretilachlor could partly be transformed to HECDEPA by Rhodococcus sp. B2. However, the effects of pretilachlor on soil bacterial communities and its complete metabolic pathway remain unknown. Herein, we investigated the mechanism of driving synergistic degradation of pretilachlor by strain B2 in the soil. The results revealed that pretilachlor showed a negative effect on bacterial communities and caused significant variations in the community structure. Strain B2 showed the ability to remediate the pretilachlor-contaminated soils and network analysis revealed that it may drive the enrichment of potential pretilachlor-degrading bacteria from the soil. The soil pretilachlor degradation may be facilitated by the members of the keystone families Comamonadaceae, Caulobacteraceae, Rhodospirillaceae, Chitinophagaceae, and Sphingomonadaceae. Meanwhile, Sphingomonas sp. M6, a member of the Sphingomonadaceae family, has been isolated from the strain B2 inoculation sample soil. The co-culture, comprising strain M6 and B2, could synergistic degrade pretilachlor within 30 h, which is the highest degradation rate. Strain M6 could completely degrade the HECDEPA via CDEPA and DEA. In the soil, a comparable pretilachlor degradation pathway may exist. This study suggested that strain B2 had the potential to drive the remediation of pretilachlor-contaminated soils.

Charge Maintenance during Catalysis in Nonheme Iron Oxygenases.

Here, the choice of the first coordination shell of the metal center is analyzed from the perspective of charge maintenance in a binary enzyme-substrate complex and an O2-bound ternary complex in the nonheme iron oxygenases. Comparing homogentisate 1,2-dioxygenase and gentisate dioxygenase highlights the significance of charge maintenance after substrate binding as an important factor that drives the reaction coordinate. We then extend the charge analysis to several common types of nonheme iron oxygenases containing either a 2-His-1-carboxylate facial triad or a 3-His or 4-His ligand motif, including extradiol and intradiol ring-cleavage dioxygenases, thiol dioxygenases, α-ketoglutarate-dependent oxygenases, and carotenoid cleavage oxygenases. After forming the productive enzyme-substrate complex, the overall charge of the iron complex at the 0, +1, or +2 state is maintained in the remaining catalytic steps. Hence, maintaining a constant charge is crucial to promote the reaction of the iron center beginning from the formation of the Michaelis or ternary complex. The charge compensation to the iron ion is tuned not only by protein-derived carboxylate ligands but also by substrates. Overall, these analyses indicate that charge maintenance at the iron center is significant when all the necessary components form a productive complex. This charge maintenance concept may apply to most oxygen-activating metalloenzymes systems that do not draw electrons and protons step-by-step from a separate reactant, such as NADH, via a reductase. The charge maintenance perception may also be useful in proposing catalytic pathways or designing prototypical reactions using artificial or engineered enzymes for biotechnological applications.