Two new compounds (1 and 2) and six known compounds (3–8) were isolated from the endophytic fungus Aspergillus fumigatus J2-22-1, and their structures were elucidated through comprehensive NMR spectroscopy and HR-ESI-MS analyses. All compounds were evaluated for PTP1B inhibitory activity. Notably, compound 1 demonstrated significant inhibition with an IC50 value of 7.36 μM, demonstrating comparable potency with the positive control Na3VO4. These findings underscore the potential of fungal metabolites as promising sources for developing novel PTP1B inhibitors.

BACKGROUND:Plant phytopathogenic fungi (PF) pose a significant threat to global agriculture by reducing crop yields and quality. The excessive use of chemical synthetic fungicides has raised concerns about environmental pollution and human health risks, while simultaneously accelerating the emergence of pathogen resistance. In this study, we aimed to discover antifungal natural products (NPs) from fungal metabolites, which represent promising eco-friendly alternatives, via bioactivity-guided isolation. RESULTS:Two novel hybrid polyketides, novomycins A and B, were isolated from Aspergillus novofumigatus J2-22. Novomycin B demonstrated broad-spectrum antifungal activity against eight PF strains, with half-maximal effective concentration (EC50) values ranging from 0.84 to 53.32 μg mL-1. Notably, novomycin B exhibited superior antifungal activity compared to the agricultural fungicide Hymexazol, achieving 100% inhibition of Botryosphaeria dothidea at 50 μg mL-1. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses revealed that novomycin B treatment caused severe destruction to the cell membrane, as evidenced by measurements of electrical conductivity, soluble protein content, and ergosterol content. Besides, novomycin B inhibited the activities of antioxidant enzymes (superoxide dismutase and catalase) in B. dothidea, leading to accumulation of hydrogen peroxide and malondialdehyde, which further exacerbated membrane system damage. Transcriptomic data indicated that novomycin B severely impaired DNA replication systems and activated extensive DNA damage repair mechanisms, which was further supported by TUNEL and EdU incorporation assays. Furthermore, it impaired energy metabolism, as confirmed by the inhibition of ATPase activity and decreased adenosine triphosphate (ATP) content. CONCLUSION:These results demonstrate that novomycin B, as a natural fungicide exhibiting multi-target antifungal mechanisms, provides a theoretical foundation for its development as an agricultural fungicide. © 2026 Society of Chemical Industry.

The accumulation of acetaminophen (APAP) in agricultural soils and water systems poses risks to ecosystems and public health. This study characterizes Acinetobacter sp. DL27, an APAP-degrading strain with broad temperature and pH adaptability, demonstrating its bioremediation potential in soil and wastewater. Through high-resolution mass spectrometry, we identified three novel metabolic intermediates, thereby refining the bacterial APAP degradation pathway. Multiomics analysis elucidated metabolic coordination and stress-tolerance mechanisms, leading to the identification of a novel amidase (AdA). Recombinant AdA exhibited activity over 10-60 °C and pH 4.0-10.0, with a Km of 8.96 ± 1.03 μM and a kcat/Km of 9.04 μM-1s-1, indicating higher catalytic efficiency than previously reported APAP amidases. Molecular dynamics simulations and site-directed mutagenesis confirmed that a Ser161-Ser185-Lys82 triad constitutes the catalytic center driving amide cleavage. These findings provide mechanistic insights into bacterial APAP biodegradation and highlight the practical application potential of strain DL27 and AdA.

Cefalexin (CFX), a prevalent β-lactam antibiotic, has increasingly been recognized as an emerging environmental contaminant,posing risks to both ecosystems and public health.In response to this challenge,researchers have isolated a novel bacterial strain,CEF13, from activated sludge,identified as Variovorax boronicumulans. This marks the first instance of a Variovorax species being reported to degrade CFX. Under optimal conditions—specifically, a temperature of 31°C, a pH of 8.3, and a 20% inoculum—strain CEF13 demonstrated remarkable efficiency, breaking down 94.61% of a 500 mg/L CFX solution within just 20 hours. Through LC-MS/MS analysis, twelve degradation intermediates were identified,shedding light on a degradation pathway involving the cleavage of the β-lactam ring,hydrolysis of amide bonds,and subsequent chemical modifications.Toxicity assays further confirmed the effectiveness of CEF13, showing that it completely neutralized the antibacterial properties of CFX. To delve deeper into the degradation mechanism, a multi-omics approach was adopted. The complete genome sequencing of CEF13,totaling 6,857,659 base pairs, revealed a diverse array of genes associated with catabolism and antibiotic resistance.Transcriptomic and proteomic analyses indicated that CEF13 responds to CFX stress by upregulating efflux pump systems,quorum sensing,and fatty acid metabolism pathways, while simultaneously downregulating ribosome synthesis and motility to conserve energy.Additionally,a pivotal β-lactamase gene, chr166 (designated blaVB1), was cloned and successfully expressed in a heterologous system. The purified BlaVB1 protein,approximately 70 kDa in size,exhibited optimal activity at 35°C and pH 7.0, directly hydrolyzing the β-lactam ring of CFX.Molecular docking studies pinpointed critical residues—ARG385, ARG392, and TRP488—responsible for substrate binding and catalysis, offering valuable insights for future drug design and bioremediation strategies.

Antibiotic resistance genes (ARGs), particularly those harbored by pathogens, pose an increasing threat to public health. Although numerous studies have investigated ARGs in Chinese lakes, the occurrence of ARGs in the littoral zones of lakes-areas particularly vulnerable to anthropogenic activities-remains poorly understood. In this study, high-throughput quantitative PCR was used to characterize ARGs in the littoral zone of Baiyang Lake, which is the largest shallow lake in northern China. A total of 254 related genes were detected, including 209 ARGs and 45 mobile genetic elements (MGEs). Both the relative abundances of ARGs and MGEs were significantly higher in the wet season than in the dry season (P < 0.05), and were higher in the tributary estuary and residential area than in the dock area and natural wetland area (P < 0.05). Network analysis revealed that wastewater discharge and animal husbandry activities are the key sources of ARGs. Water physicochemical parameters, antibiotics, and MGEs were identified as the primary positive drivers during both the wet and dry seasons. The findings underscore the urgent need for improved wastewater treatment, enhanced human and animal husbandry waste management, and stricter regulation of antibiotic use. Overall, this work offers novel perspectives on the spatiotemporal distribution, human health risks, and driving mechanisms of ARGs in shallow lake littoral zones. They also provide a scientific basis for strengthening monitoring and implementing targeted environmental management strategies for ARG pollution.

Cephalosporin residues in agricultural soils, food systems, and aquatic environments pose severe threats to food safety, public health, and the ecological environment. While biodegradation represents a promising remediation strategy, the degradation mechanisms for most cephalosporins remain elusive. In this study, Pseudochrobactrum asaccharolyticum TY12 was isolated and demonstrated a broad-spectrum ability to degrade multiple cephalosporins. Notably, strain TY12 exhibited the highest cefixime (CFX) degradation efficiency, achieving a 93.87% removal of 100 mg/L CFX within 12 h. Ten degradation products of CFX were identified via high-resolution mass spectrometry, leading to a proposed degradation pathway. Notably, these products exhibited significantly attenuated antibacterial activity. Transcriptomic analysis and heterologous expression identified β-lactamase TY3865 as the key enzyme. Furthermore, molecular docking and site-directed mutagenesis revealed the residues critical for its catalytic activity. These findings provide mechanistic insights into antibiotic biodegradation and demonstrate the potential of TY12 for treating cephalosporin-contaminated wastewater.

Chemical investigation of Fusarium sp. HM14 led to the isolation of five cyclodepsipeptides (1–5), with compound 1 being undescribed. Their structures were elucidated via HR-ESI-MS, 1D, 2D NMR, and literature comparison; the absolute configuration of compound 1 was determined using Marfey’s method. Compounds 1–5 displayed cytotoxic activity to varying extents against both MCF-7 and MGC-803 cells, with IC50 values within the range 3.04–80.57 μg·mL–1.

Phthalate esters (PAEs) constitute a widespread class of xenobiotic contaminants characterized by environmental persistence and ecological recalcitrance. Under aerobic conditions, PAE mineralization proceeds via 4,5-dihydroxyphthalate (4,5-DHP) as a key metabolic intermediate, which undergoes stereospecific decarboxylation to protocatechuate (PCA), a versatile pharmacophore with broad therapeutic potential. Here, we elucidate the molecular architecture and catalytic determinants of a previously uncharacterized 4,5-DHP decarboxylase (DhpD) isolated from ultramicrobacteria. Enzymatic assays revealed that PAE-UM2851 exhibits peak activity at pH 7.5 and 45 °C, with a Km of 911.5 μM. Functional characterization confirmed that PAE-UM2851 catalyzes the decarboxylation of 4,5-DHP to PCA, supported by FTIR spectral evidence showing reduced - CO (1640 cm-1) and - OH (3450 cm-1) vibrational modes. Structure-function analysis identified five evolutionarily conserved residues (Ser57, Arg84, Thr115, Lys150, and His223) essential for regulating regioselective decarboxylation. This study not only clarifies the catalytic mechanism of DhpD but also outlines a potential biosynthetic route for PCA.

The diversity and functions of metallothioneins (MTs) in Archaea remain poorly understood. This study identifies 180 archaeal MTs from 406 genomes, revealing distinct evolutionary lineages and structural diversity. Phylogenetic analysis suggests a novel class with divergent ancestry. AlphaFold3-based modeling highlights conserved Cys-rich motifs and irregular structures, potentially enhancing adaptation to extreme environments. Functional assays show that four MTs (MT334126, MT382228, MT114104, and MT282443) increase cadmium resistance, while MT334126 and MT382228 also enhance copper resistance. Targeted mutations at key sites boost metal adsorption, validated by structural modeling. This work provides the first comprehensive insight into archaeal MTs, laying the foundation for environmental and biotechnological applications.

Cephalexin (CEX), a prevalent (3-lactam antibiotic, contaminates the environment, posing risks to human and ecological health. While microorganisms play a key role in CEX degradation, the underlying molecular mechanisms remain largely unknown. To address this, we isolated a CEX-degrading bacterium, Brevundimonas sp. CEF1, from sediment. The strain shown 94.26 % CEX degradation rate within 8 h under optimized culture conditions. Base on the UHPLC-Q-Orbitrap HRMS results, three CEX degradation pathways including a novel pathway with hydroxylation as initial steps were proposed. Importantly, the resulting degradation products lacked antibacterial activity. Integrated genomic and transcriptomic analyses highlighted the crucial roles of genes involved in stress response and enzymatic transformation, with (3-lactamases and cytochrome P450 enzymes mediating the initial steps of CEX degradation. The function of (3-lactamase AmpC in CEX degradation was further validated through heterologous expression. Furthermore, combined molecular docking and site-directed mutagenesis studies confirmed the critical roles of residues Ser197, Asn408, Tyr262, Tyr287, Trp390, and Arg257 in the AmpC-mediated hydrolysis of CEX. This study provides novel molecular insights into the mechanisms of microbial CEX degradation and offers desirable strain and enzyme resources for the bioremediation of (3-lactam antibiotic-contaminated wastewater.

BACKGROUND:Preeclampsia is characterized by maternal endothelial dysfunction and new-onset hypertension. Preeclamptic pregnancies have elevated levels of maternal soluble prorenin receptor (s(P)RR) and previous studies have shown that recombinant s(P)RR produces hypertension and vascular dysfunction. This study aimed to investigate the effects of PRO20, an s(P)RR antagonist, on s(P)RR-induced endothelial dysfunction and its interaction with the Angiotensin II Type 1 Receptor (AT1R). METHODS:Human uterine microvascular endothelial cells (HUtMECs) were treated with 100nM s(P)RR, with/without 10nM PRO20, 10μM Losartan (AT1R antagonist), or 10μM Aliskerin (renin inhibitor). The ability of PRO20 to prevent endothelial dysfunction induced by patient serum from preeclamptic pregnancies was also assessed. Endothelial dysfunction markers were measured using immunoblot, qPCR, and ELISA. For AT1R mechanism studies, HUtMECs were treated with control or AT1R siRNA before s(P)RR exposure. AT1R and s(P)RR protein structures were predicted via AlphaFold-2 and docking examined using Schrödinger. RESULTS:PRO20 mitigated s(P)RR-induced increases in the mRNA expression of endothelial dysfunction markers, endothelin-1, VCAM-1 and ICAM-1 and prevented s(P)RR and preeclamptic serum-induced increases in endothelin-1 and VCAM-1 protein. Aliskerin had no effect on s(P)RR-induced endothelial dysfunction. Losartan and an AT1R siRNA were able to prevent s(P)RR induced increases in VCAM-1 protein levels and ET-1 mRNA expression, respectively. Modelling suggested that PRO20 can impair s(P)RR-AT1R complex formation. CONCLUSIONS:Elevated s(P)RR induces endothelial dysfunction at least partially through AT1R. PRO20 prevents s(P)RR-AT1R formation, suggesting it could be an effective therapeutic for preeclampsia and conditions requiring renin-angiotensin system suppression.

Phthalates (PAEs), such as dibutyl phthalate (DBP), are emerging contaminants in agriculture that are commonly used in plastic films, pesticides, and soil amendments. Their accumulation in water threatens ecosystems and human health. Biodegradation offers a promising solution, but the DBP degradation mechanisms remain unclear. This study identified two 4,5-PCD isoenzymes (PCD34 and PCD67) in Curvibacter sp. PAE-UM. PCD34 showed higher affinity and broader substrate specificity, while PCD67 had better thermal stability and metal ion sensitivity. Both enzymes converted protocatechuate (PCA) to 4CHMS at 45% efficiency in 5 min. Molecular dynamics revealed the stable binding of PCD67, while mutagenesis enhanced PCD34 activity (124.4%) by reducing steric hindrance. These findings may aid in the engineering of strains for PAE bioremediation in agricultural wastewater.

Microplastic pollution is a major environmental threat, especially to terrestrial ecosystems. To better understand the effects of microplastics on soil microbiota, the influence of micro- to nano-scale polypropylene plastics was investigated on microbial community diversity, functionality, co-occurrence, assembly, and their interaction with soil-plant using high-throughput sequencing approaches and multivariate analyses. The results showed that polypropylene micro/nano-plastics mainly reduced bacterial diversity, not fungal, and that plastic size had a stronger effect than concentration on the assembly of microbial communities. Nano-plastics decreased the complexity and connectivity of both bacterial and fungal networks compared to micro-plastics. Moreover, bacteria were more sensitive and deterministic to polypropylene micro/nano-plastic stress than fungi, as shown by their different growth rates, guanine-cytosine content, and cell structure. Interestingly, the dominant ecological process for bacteria shifted from stochastic drift to deterministic selection with polypropylene micro/nano-plastic exposure. Furthermore, nano-plastics directly or indirectly disrupted the interactions within intra-microbes and between soil-bacteria-plant by altering soil nutrients and stoichiometry (C:N:P) or plant diversity. Collectively, the results indicate that polypropylene nano-plastics pose more ecological risks to soil microbes and their plant-soil interactions. This study sheds light on the potential ecological consequences of polypropylene micro/nano-plastic pollution in terrestrial ecosystems.

Polyacrylamide (PAM) is a high-molecular-weight polymer with extensive applications. However, the inefficient natural degradation of PAM results in environmental accumulation of the polymer. Biodegradation is an environmentally friendly approach in the field of PAM treatment. The first phase of PAM biodegradation is the deamination of PAM, forming the product poly(acrylic acid) (PAA). The second phase of PAM biodegradation involves the cleavage of PAA into small molecules, which is a crucial step in the degradation pathway of PAM. However, the enzyme that catalyzes the degradation of PAA and the molecular mechanism remain unclear. Here, a novel monooxygenase PCX02514 is identified as the key enzyme for PAA degradation. Through biochemical experiments, the monooxygenase PCX02514 oxidizes PAA with the participation of NADPH, causing the cleavage of carbon chains and a decrease in the molecular weight of PAA. In addition, the crystal structure of the monooxygenase PCX02514 is solved at a resolution of 1.97 Å. The active pocket is in a long cavity that extends from the C-terminus of the TIM barrel to the protein surface and exhibits positive electrostatic potential, thereby causing the migration of oxygen-negative ions into the active pocket and facilitating the reaction between the substrates and monooxygenase PCX02514. Moreover, Arg10-Arg125-Ser186-Arg187-His253 are proposed as potential active sites in monooxygenase PCX02514. Our research characterizes the molecular mechanism of this monooxygenase, providing a theoretical basis and valuable tools for PAM bioremediation.

The protocatechuate 4,5-dioxygenase (4,5-PCD) plays a pivotal role in phthalate esters (PAEs) degradation, catalyzing the ring-opening reaction of protocatechuic acid (PCA) to participate in PAEs metabolic degradation. Through the analysis of whole-genome of Curvibacter sp. PAE-UM and relevant literature, we identified two novel 4,5-PCDs, designated as PCD34 and PCD67 due to different open reading frame (ORF) locations. Both enzymes were confirmed to be isoenzymes. The optimal temperature and pH for PCD34 and PCD67 were identified as 55 ℃ and 8.0, respectively, with Km and kcat values of 251.17 µM and 1.23 s-1 for PCD34, and 409.76 µM and 1.16 s-1 for PCD67. PCD34 exhibited higher affinity and catalytic efficiency, while PCD67 displayed greater thermostability and sensitivity to metal ions. Structural models of the binding of 4,5-PCD isoenzymes to PCA were proposed through induced fit docking (IFD) and molecular dynamics (MD) simulations. In addition, seven critical amino acid residues were identified in PCD34 and PCD67, and the ring-opening cleavage mechanism of iron-independent 4,5-PCD isoenzymes were inferred. This study provides experimental evidence and references for investigating 4,5-PCD isoenzymes in other species, and offers new insights into their potential applications in biodegradation of PAE pollutants and environmental remediation.

Polyacrylamide (PAM) is a high molecular weight polymer with extensive applications. However, inefficient natural degradation of PAM results in its environmental accumulation. Here, using multi-omics analysis, we constructed the PAM biodegradation pathway in Klebsiella sp. PCX, an efficient PAM-degrading bacterium. Subsequently, two unclassified amidohydrolases (PCX00451 and PCX04581) were identified as key factors for rapid PAM biodegradation, both of which possessed much higher hydrolysis efficiency for PAM than for small molecule amide compounds. Besides, crystal structures of PCX00451 and PCX04581 were solved. Both two amidohydrolases were consisted with a twisted triosephosphateisomerase (TIM)-barrel and a smaller β-sandwich domain. And their binding pockets were in the conserved metal center of TIM-barrel domain. Moreover, Asp267 of PCX00451 and Asp282 of PCX04581 were examined as active sites for acid/base catalysis. Our research characterized the molecular mechanisms of two efficient amidohydrolases, providing theoretical basis and valuable tools for PAM bioremediation.

Bisphenol P (BPP) has been detected in human biological samples; however studies on its nephrotoxicity are scarce. Given the susceptibility of kidneys to endocrine-disrupting chemicals, there is an urgent need to investigate the renal toxicity of BPP. This study aimed to evaluate the effects of different concentrations of BPPs on the kidneys of C57BL/6 mice and elucidate the underlying mechanisms of renal damage using a combination of mouse renal transcriptomic data and human renal proximal tubular epithelial cells (HK-2). Mice were exposed to BPP (0, 0.3, 30, 3000 mu g/kg bw/d) via gavage for 5 weeks. Renal injury was assessed based on changes in body and kidney weights, serum renal function indices, and histopathological examination. Transcriptomic analysis identified differentially expressed genes and pathways, whereas cellular assays were used to measure cell viability, reactive oxygen species (ROS), apoptosis, and the expression of key genes and proteins. The results show that BPP exposure induces renal injury, as evidenced by increased body weight, abnormal renal function indices, and renal tissue damage. Transcriptomic analysis revealed alterations in genes and pathways related to oxidative stress, p53 signaling, autophagy, and apoptosis. Cellular experiments confirmed that BPP induces oxidative stress and apoptosis. Furthermore, BPP exposure significantly inhibits autophagy, potentially exacerbating apoptosis and contributing to kidney injury. Treatment with a ROS inhibitor (N-Acetylcysteine, NAC) mitigated BPP-induced autophagy inhibition and apoptosis, implicating oxidative stress as a key factor. BPP exposure may lead to renal injury through excessive ROS accumulation, oxidative stress, inflammatory responses, autophagy inhibition, and increased apoptosis. The effects of NAC highlight the role of oxidative stress in BPP-induced nephrotoxicity. These findings enhance our understanding of BPP-induced nephrotoxicity and underscore the need to control BPP exposure to prevent renal disease. This study emphasized the importance of evaluating the safety of new Bisphenol A analogs, including BPP, in environmental toxicology.

Protein natural diversity offers a vast sequence space for protein engineering, and deep learning enables its detection from metagenomes/proteomes without prior assumptions. DeepMetagenome, a Python-based method, explores protein diversity through modules for training and analyzing sequence datasets. The deep learning model includes Embedding, Conv1D, LSTM, and Dense layers, with sequence feature analysis for data cleaning. Applied to metallothioneins from a database of over 146 million coding features, DeepMetagenome identified over 500 high-confidence metallothionein sequences, outperforming DIAMOND and CNN-based models. It showed stable performance compared to a Transformer-based model over 25 epochs. Among 23 synthesized sequences, 20 exhibited metal resistance. The tool also successfully explored the diversity of three additional protein families and is freely available on GitHub with detailed instructions.

WUSCHEL-related homeobox (WOX) proteins participate profoundly in plant development and stress responses. As the difficulty of somatic embryogenesis severely constrains cotton genetic modification, in this study, we identified and comprehensively analyzed WOX genes in cotton. As a result, 40 WOX genes were identified in the upland cotton genome. All these cotton WOX genes were classified into three clades, ancient, intermediate, and modern clades, based on the phylogenetic analysis of previous studies. The majority (24) of the cotton WOX genes belonged to the modern clade, in which all gene members contain the vital functional domain WUS-box, which is necessary for plant stem cell regulation and maintenance. Collinearity analysis indicated that the WOX gene family in cotton expanded to some degree compared to Arabidopsis, especially in the modern clade. Genome duplication and segmental duplication may greatly contribute to expansion. Hormone-response- and abiotic-stress-response-related cis-acting regulatory elements were widely distributed in the promoter regions of cotton WOX genes, suggesting that the corresponding functions of stress responses and the participation of development processes were involved in hormone responses. By RNA sequencing, we profiled the expression patterns of cotton WOX genes in somatic embryogenesis. Only about half of cotton WOX genes were actively expressed during somatic embryogenesis; different cotton WOX genes may function in different development stages. The most representative, GhWOX4 and GhWOX13, may function in almost all stages of somatic embryogenesis; GhWOX2 and GhWOX9 function in the late stages of embryo patterning and embryo development during cotton somatic embryogenesis. Co-expression analysis showed that the cotton WOXs co-expressed with genes involved in extensive genetic information processing, including DNA replication, DNA repair, homologous recombination, RNA transport, protein processing, and several signaling and metabolism pathways, in which plant hormones signal transduction, MAPK signaling pathways, phosphatidylinositol signaling systems, and ABC transporters, as well as the metabolism of fatty acid; valine, leucine, and isoleucine biosynthesis; and cutin, suberine, and wax biosynthesis, were most significantly enriched. Taken together, the present study provides useful information and new insights into the functions of cotton WOX genes during somatic embryogenesis. The specific regulatory roles of some WOX genes in somatic embryogenesis are worthy of further functional research.