Effects of Enterobacter cloacae insecticidal protein on the Duox-ROS system and midgut bacterial community and function of Galleria mellonella larvae.

BACKGROUND: Enterobacter cloacae insecticidal proteins have been reported to kill Galleria mellonella larvae through affecting their midgut microbiome. However, the mechanisms involved remain unclear. Here we aim to investigate how the insecticidal proteins act on the midgut Duox-ROS system and microbial community of G. mellonella larvae. METHODS: Reverse transcription qPCR and fluorescence probes were utilized to assess the Duox expression levels and to evaluate quantitative changes of the ROS levels. Sequencing of the 16S rRNA gene sequences of the midgut bacteria of G. mellonella larvae was conducted for further analyses of bacterial diversity, composition, and abundance. RESULTS: After the injection of the insecticidal proteins, the Duox expression levels first increased within 28 h, then dramatically peaked at 36 h, and slowly decreased thereafter. Simultaneously, the ROS levels increased significantly at 36 h, peaked at 48 h, and rapidly declined to the normal level at 60 h. Responsive to the change of the ROS levels, the structure of the midgut microbial community was altered substantially, compared to that of the untreated larvae. The relative abundance of Enterobacteriaceae and other specific pathogenic bacteria increased significantly, whereas that of Lactobacillus decreased sharply. Importantly, notable shifts were observed in the crucial midgut predicted metabolic functions, including membrane transportation, carbohydrate metabolism, and amino acid metabolism. CONCLUSION: Insecticidal proteins of E. cloacae kill G. mellonella larvae mainly through generation of high oxidative stress, alterations of the midgut microbial community and function, and damage to the physiological functions. These findings provide insights into the inhibition mechanism of E. cloacae insecticidal proteins to G. mellonella larvae.

High-throughput method for screening pendimethalin-degrading bacteria from one microbial bank.

The extensive use of chemical pesticides, such as herbicides, has resulted in significant environmental pollution. Microbial degradation represents a crucial approach for managing this pesticide-associated pollution, with enrichment culturing serving as a method for isolating pesticide-degrading microorganisms. However, the efficiency of this strategy is limited, often yielding only a few isolated strains. In this study, a new mineral salt medium (MSM) was developed, and a high-throughput method was used for screening pendimethalin-degrading bacteria by measuring the bacterial growth in the MSM. The utilization of this method resulted in the isolation of 56 pendimethalin-degrading bacteria from approximately 2 000 bacterial strains, including 37 Bacillus spp., 10 Alcaligenes spp., 5 Pseudomonas spp., and other 4 strains identified for the first time as pendimethalin-degrading strains. This method may hold promise not only for isolating bacterial strains capable of degrading other pesticides but also for facilitating the utilization of the substantial bacterial strains stored in bacterial banks.

Applications of nanotechnology in remodeling the tumour microenvironment for glioblastoma treatment.

With the increasing research and deepening understanding of the glioblastoma (GBM) tumour microenvironment (TME), novel and more effective therapeutic strategies have been proposed. The GBM TME involves intricate interactions between tumour and non-tumour cells, promoting tumour progression. Key therapeutic goals for GBM treatment include improving the immunosuppressive microenvironment, enhancing the cytotoxicity of immune cells against tumours, and inhibiting tumour growth and proliferation. Consequently, remodeling the GBM TME using nanotechnology has emerged as a promising approach. Nanoparticle-based drug delivery enables targeted delivery, thereby improving treatment specificity, facilitating combination therapies, and optimizing drug metabolism. This review provides an overview of the GBM TME and discusses the methods of remodeling the GBM TME using nanotechnology. Specifically, it explores the application of nanotechnology in ameliorating immune cell immunosuppression, inducing immunogenic cell death, stimulating, and recruiting immune cells, regulating tumour metabolism, and modulating the crosstalk between tumours and other cells.

Organosiloxane membranes for heavy aromatic oil fractionation.

The industrial separation of hydrocarbons relies on distillation. Organic solvent nanofiltration can provide an energy-efficient alternative. We prepared high performance organosiloxane membranes for fractionation of heavy aromatics. They achieved a high permeance up to 0.13 L m-2 h-1 bar-1, with a rejection rate of 88.7% for hydrocarbons with five aromatic rings.

Chromodomain Y-like (CDYL) inhibition ameliorates acute kidney injury in mice by regulating tubular pyroptosis.

Acute kidney injury (AKI) is a common disease, but lacking effective drug treatments. Chromodomain Y-like (CDYL) is a kind of chromodomain protein that has been implicated in transcription regulation of autosomal dominant polycystic kidney disease. Benzo[d]oxazol-2(3H)-one derivative (compound D03) is the first potent and selective small-molecule inhibitor of CDYL (KD = 0.5 µM). In this study, we investigated the expression of CDYL in three different models of cisplatin (Cis)-, lipopolysaccharide (LPS)- and ischemia/reperfusion injury (IRI)-induced AKI mice. By conducting RNA sequencing and difference analysis of kidney samples, we found that tubular CDYL was abnormally and highly expressed in injured kidneys of AKI patients and mice. Overexpression of CDYL in cisplatin-induced AKI mice aggravated tubular injury and pyroptosis via regulating fatty acid binding protein 4 (FABP4)-mediated reactive oxygen species production. Treatment of cisplatin-induced AKI mice with compound D03 (2.5 mg·kg-1·d-1, i.p.) effectively attenuated the kidney dysfunction, pathological damages and tubular pyroptosis without side effects on liver or kidney function and other tissue injuries. Collectively, this study has, for the first time, explored a novel aspect of CDYL for tubular epithelial cell pyroptosis in kidney injury, and confirmed that inhibition of CDYL might be a promising therapeutic strategy against AKI.

Recent advances in nanocellulose based hydrogels: Preparation strategy, typical properties and food application.

Nanocellulose has been favored as one of the most promising sustainable nanomaterials, due to its competitive advantages and superior performances such as hydrophilicity, renewability, biodegradability, biocompatibility, tunable surface features, excellent mechanical strength, and high specific surface area. Based on the above properties of nanocellulose and the advantages of hydrogels such as high water absorption, adsorption, porosity and structural adjustability, nanocellulose based hydrogels integrating the benefits of both have attracted extensive attention as promising materials in various fields. In this review, the main fabrication strategies of nanocellulose based hydrogels are initially discussed in terms of different crosslinking methods. Then, the typical properties of nanocellulose based hydrogels are comprehensively summarized, including porous structure, swelling ability, adsorption, mechanical, self-healing, smart response performances. Especially, relying on these properties, the general application of nanocellulose based hydrogels in food field is also discussed, mainly including food packaging, food detection, nutrient embedding delivery, 3D food printing, and enzyme immobilization. Finally, the safety of nanocellulose based hydrogel is summarized, and the current challenges and future perspectives of nanocellulose based hydrogels are put forward.

Rational design of structure-based vaccines targeting misfolded alpha-synuclein conformers of Parkinson's disease and related disorders.

Synucleinopathies, including Parkinson's disease (PD), multiple system atrophy (MSA), and dementia with Lewy bodies (DLB), are neurodegenerative disorders caused by the accumulation of misfolded alpha-synuclein protein. Developing effective vaccines against synucleinopathies is challenging due to the difficulty of stimulating an immune-specific response against alpha-synuclein without causing harmful autoimmune reactions, selectively targeting only pathological forms of alpha-synuclein. Previous attempts using linear peptides and epitopes without control of the antigen structure failed in clinical trials. The immune system was unable to distinguish between native alpha-synuclein and its amyloid form. The prion domain of the fungal HET-s protein was selected as a scaffold to introduce select epitopes from the surface of alpha-synuclein fibrils. Four vaccine candidates were generated by introducing specific amino acid substitutions onto the surface of the scaffold protein. The approach successfully mimicked the stacking of the parallel in-register beta-sheet structure seen in alpha-synuclein fibrils. All vaccine candidates induced substantial levels of IgG antibodies that recognized pathological alpha-synuclein fibrils derived from a synucleinopathy mouse model. Furthermore, the antisera recognized pathological alpha-synuclein aggregates in brain lysates from patients who died from DLB, MSA, or PD, but did not recognize linear alpha-synuclein peptides. Our approach, based on the rational design of vaccines using the structure of alpha-synuclein amyloid fibrils and strict control over the exposed antigen structure used for immunization, as well as the ability to mimic aggregated alpha-synuclein, provides a promising avenue toward developing effective vaccines against alpha-synuclein fibrils.

Optimal harvest period and quality control markers of cultivated Flos Chrysanthemi Indici using untargeted/targeted metabolomics, chemometric analysis and in vivo study.

ETHNOPHARMACOLOGICAL RELEVANCE: Flos Chrysanthemi Indici (FCI), the flower of Chrysanthemum Indicum L., is a popular traditional Chinese medicine (TCM) for treatment of inflammatory diseases in China. FCI is also a functional food, and is widely used as herbal tea for clearing heat and detoxicating. AIM OF THE STUDY: To explore quality control markers of FCI based on the optimal harvest period. MATERIALS AND METHODS: First, UPLC-Q-TOF/MS based untargeted metabolomics was applied to explore the chemical profiles of FCIs collected at bud stages (BS), initial stages (IS), full bloom stages (FS) and eventual stages (ES) from eight cultivated regions in China. Subsequently, lipopolysaccharide (LPS)-induced RAW264.7 cell inflammatory model and carrageenan-induced rat paw edema model were used to confirm the anti-inflammatory effect of FCIs collected at IS/FS. Then, UPLC-PDA targeted metabolomics was used to quantitatively analyze 9 constituents with anti-inflammatory activity (7 flavonoids and 2 phenolic acids) changed significantly (VIP > 4) during flowering stages. Finally, ROC curves combined with PCA analysis based on the variation of 9 active constituents in FCIs from different flowering stages were applied to screen the quality markers of FCI. RESULTS: FCIs at IS/FS had almost same chemical characteristics, but quite different from those at BS and ES. A total of 32 constituents in FCIs including flavonoids and phenolic acids were changed during flowering development. Most of the varied constituents had the highest or higher contents at IS/FS compared with those at ES, indicating that the optimal harvest period of FCI should be at IS/FS. FCI extract could effectively suppress nitric oxide (NO) production in LPS-induced RAW264.7 cells and regulate the abnormal levels of cytokines and PGE2 in carrageenan-induced paw edema model rat. The results of quantitatively analysis revealed that the variation trends of phenolic acids and flavonoids in FCIs were different during flowering development, but most of them had higher contents at IS/FS than those at ES in all FCIs collected from eight cultivated regions, except one sample from Anhui. Finally, linarin, luteolin, apigenin and 3,5-dicaffeoylquinic acid were selected as the Q-markers based on the contribution of their AUC values in ROC and clustering of PCA analysis. CONCLUSIONS: Our study demonstrates the optimal harvest period of FCI and specifies the multi-constituents Q-markers of FCI based on the influence of growth progression on the active constituents using untargeted/targeted metabolomics. The findings not only greatly increase the utilization rate of FCI resources and improve quality control of FCI products, but also offer new strategy to identify the Q-markers of FCI.

Ultrasmall magnolol/ebselen nanomicelles for preventing renal ischemia/reperfusion injury.

Renal ischemia/reperfusion injury (RIRI) is an inevitable complication following kidney transplantation surgery, accompanied by the generation of a large amount of free radicals. A cascade of events including oxidative stress, extreme inflammation, cellular apoptosis, and thrombosis disrupts the microenvironment of renal cells and the hematological system, ultimately leading to the development of acute kidney injury (AKI). The current research primarily focuses on reducing inflammation and mitigating damage to renal cells through antioxidative approaches. However, studies on simultaneously modulating the renal hematologic system remain unreported. Herein, potent and novel drug-loaded nanomicelles can be efficiently self-assembled with magnolol (MG) and ebselen (EBS) by π-π conjugation, hydrophobic action and the surfactant properties of Tween-80. The ultrasmall MG/EBS nanomicelles (average particle size: 10-25 nm) not only fully preserve the activity of both drugs, but also greatly enhance drug utilization (encapsulation rates: MG: 90.1%; EBS: 49.3%) and reduce drug toxicity. Furthermore, EBS, as a glutathione peroxidase mimic and NO catalyst, combines with the multifunctional MG to scavenge free radicals and hydroperoxides, significantly inhibiting inflammation and thrombosis while effectively preventing apoptosis of vascular endothelial cells and renal tubular epithelial cells. This study provides a new strategy and theoretical foundation for the simultaneous regulation of kidney cells and blood microenvironment stability.

From Pb6(HPO3)(H2PO3)Cl9 to Pb6(HPO3)2Br8(H2O)·H2O: Halogen Regulation to Achieve Inorganic Metal Phosphite Halide Nonlinear Optical Material with Unprecedented Pb-Centered Polyhedral Units.

Nonlinear optical (NLO) crystals are widely used in various fields. The introduction of lone-pair cations is regarded as an effective strategy to explore NLO crystals. In this work, two novel lead phosphite halides, centrosymmetric Pb6(HPO3)(H2PO3)Cl9 and noncentrosymmetric Pb6(HPO3)2Br8(H2O)·H2O, were obtained via a hydrothermal method. Pb6(HPO3)(H2PO3)Cl9 is the first reported lone-pair metal phosphite with two kinds of phosphite groups (HPO32- and H2PO3-) and Pb6(HPO3)2Br8(H2O)·H2O is the first inorganic NLO phosphite halide with a phase-matchable SHG effect of 1.02 × KDP. In addition, the Pb-centered polyhedral units of PbOCl4, PbOCl6, PbO2Cl5, PbO2Br5, PbOBr6, and PbO3(H2O)Br3 in these two structures have never been reported before. An in-depth study on the structure-property relationship of the two compounds with halogen substitution is also performed.

A High-Throughput Screening Strategy for Synthesizing Molecularly Imprinted Polymer Nanoparticles Selectively Targeting Tumors.

Molecularly imprinted polymers (MIPs) show significant promise as effective alternatives to antibodies in disease diagnosis and therapy. However, the challenging process of screening extensive libraries of monomer combinations and synthesis conditions to identify formulations with enhanced selectivity and affinity presents a notable time constraint. The need for expedient methods becomes clear in accelerating the strategic development of MIPs tailored for precise molecular recognition purposes. In this study, an innovative high-throughput screening methodology designed to identify the optimal MIP formulation for targeting tumors is presented. Employing a microtiter plate format, over 100 polymer syntheses are conducted, incorporating diverse combinations of functional monomers. Evaluation of binding performance utilizes fluorescence-based assays, focusing on an epitope of the epidermal growth factor receptor (EGFR). Through this meticulously structured screening process, synthesis conditions that produced MIP nanoparticles exhibiting substantial specificity for EGFR targeting (KD = 10-12 m) are identified. These "bionic antibodies" demonstrate selective recognition of cancer cells in whole blood samples, even at concentrations as low as 5 cells mL-1. Further validation through fluorescent imaging confirms the tumor-specific localization of the MIPs in vivo. This highly efficient screening approach facilitates the strategic synthesis of imprinted polymers functioning as precision bioprobes.

Therapeutic analysis of 632 cases treated by transcatheter arterial chemoembolization combined with ablation in hepatocellular carcinoma: A retrospective study.

OBJECTIVES: This study aims to analyze the efficacy of transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) in hepatocellular carcinoma (HCC). METHODS: A retrospective analysis was conducted on 632 patients with HCC at Barcelona Clinic Liver Cancer Staging (BCLC) System stages 0, A, and B from Beijing You'an Hospital affiliated with Capital Medical University. The primary outcomes analyzed were overall survival (OS) and progression-free survival (PFS), while the secondary outcomes included one-, three-, and five-year OS rates among different groups. RESULTS: The median follow-up period for 632 cases identified with HCC was 52.1 months (range: 3-162 months), while 127 patients died during follow-up. The one-, three-, and five-year OS rates were 97.1 %, 89.5 %, and 80.4 %, respectively. Moreover, the one-, three-, and five-year PFS rates were 58.1 %, 29.3 %, and 19.8 %, respectively. Multivariate analysis revealed that the BCLC stages and complete ablation were independent predictors of OS and PFS (all p < 0.05). Subgroup analysis showed no difference in OS rate among TACE-RFA, TACE-MWA, and TACE-CA groups, but TACE-CA showed better efficacy in improving the PFS rate (all p < 0.05). CONCLUSIONS: The combination of TACE and ablation is effective in early-stage HCC and BCLC stage B. Complete ablation and BCLC stages are significant prognostic factors for PFS and OS. Further research, including randomized controlled trials, is needed to validate these findings.

scVIC: deep generative modeling of heterogeneity for scRNA-seq data.

Motivation: Single-cell RNA sequencing (scRNA-seq) has become a valuable tool for studying cellular heterogeneity. However, the analysis of scRNA-seq data is challenging because of inherent noise and technical variability. Existing methods often struggle to simultaneously explore heterogeneity across cells, handle dropout events, and account for batch effects. These drawbacks call for a robust and comprehensive method that can address these challenges and provide accurate insights into heterogeneity at the single-cell level. Results: In this study, we introduce scVIC, an algorithm designed to account for variational inference, while simultaneously handling biological heterogeneity and batch effects at the single-cell level. scVIC explicitly models both biological heterogeneity and technical variability to learn cellular heterogeneity in a manner free from dropout events and the bias of batch effects. By leveraging variational inference, we provide a robust framework for inferring the parameters of scVIC. To test the performance of scVIC, we employed both simulated and biological scRNA-seq datasets, either including, or not, batch effects. scVIC was found to outperform other approaches because of its superior clustering ability and circumvention of the batch effects problem. Availability and implementation: The code of scVIC and replication for this study are available at https://github.com/HiBearME/scVIC/tree/v1.0.

SKLB023 protects against inflammation and apoptosis in sepsis-associated acute kidney injury via the inhibition of toll-like receptor 4 signaling.

Sepsis-associated acute kidney injury (SA-AKI) is one of common critical illnesses with high morbidity and mortality. At present, effective therapeutic drugs for SA-AKI are remain lacking. SKLB023 is a synthetic small-molecule compound which exerts potent anti-inflammatory effects in our previous studies. Here, this study aimed to characterize the protective effect of SKLB023 on SA-AKI and explore its underlying mechanism. The SA-AKI experimental models have been established by cecum ligation/puncture (CLP) and lipopolysaccharide (LPS) injection in male C57BL/6J mice. SKLB023 was administered by gavage (50 or 25 mg/kg in CLP model and 50 mg/kg in LPS model) daily 3 days in advance and 30 min earlier on the day of modeling. Our results confirmed SKLB023 treatment could improve the survival of SA-AKI mice and ameliorate renal pathological injury, inflammation, and apoptosis in the two types of septic AKI mice. Mechanically, SKLB023 deceased the expression of TLR4 in LPS-triggered renal tubular epithelial cells, and inhibited the activation of downstream pathways including NF-κB and MAPK pathways. Our study suggested that SKLB023 is expected to be a potential drug for the prevention and treatment of septic AKI.

Highly Specific Aptamer-Antibody Birecognized Sandwich Module for Ultrasensitive Detection of a Low Molecular Weight Compound.

Herein, the aptamer-antibody sandwich module was first introduced to accurately recognize a low molecular weight compound (mycotoxin). Impressively, compared with the large steric hindrance of a traditional dual-antibody module, the aptamer-antibody sandwich with low Gibbs free energy and a low dissociation constant has high recognition efficiency; thus, it could reduce false positives and false negatives caused by a dual-antibody module. As a proof of concept, a sensitive electrochemiluminescence (ECL) biosensor was constructed for detecting mycotoxin zearalenone (ZEN) based on an aptamer-antibody sandwich as a biological recognition element and porous ZnO nanosheets (Zn NSs) supported Cu nanoclusters (Cu NCs) as the signal transduction element, in which the antibody was modified on the vertex of a tetrahedral DNA nanostructure (TDN) with a rigid structure to increase the kinetics of target recognition for promoting the detection sensitivity. Moreover, the Cu NCs/Zn NSs exhibited an excellent ECL response that was attributed to the aggregation-induced ECL enhancement through electrostatic interactions. The sensing platform achieved trace detection of ZEN with a low detection limit of 0.31 fg/mL, far beyond that of the enzyme-linked immunosorbent assay (ELISA, the current rapid detection method) and high-performance liquid chromatography (HPLC, the national standard detection method). The strategy has great application potential in food analysis, environmental monitoring, and clinical diagnosis.

Senescent endothelial cells promote liver metastasis of uveal melanoma in single-cell resolution.

BACKGROUND: Uveal melanoma (UM), the most common adult intraocular tumor, is characterized by high malignancy and poor prognosis in advanced stages. Angiogenesis is critical for UM development, however, not only the role of vascular endothelial dysfunction in UM remains unknown, but also their analysis at the single-cell level has been lacking. A comprehensive analysis is essential to clarify the role of the endothelium in the development of UM. METHODS: By using single-cell RNA transcriptomics data of 11 cases of primary and liver metastasis UM, we analyzed the endothelial cell status. In addition, we analyzed and validated ECs in the in vitro model and collected clinical specimens. Subsequently, we explored the impact of endothelial dysfunction on UM cell migration and explored the mechanisms responsible for the endothelial cell abnormalities and the reasons for their peripheral effects. RESULTS: UM metastasis has a significantly higher percentage of vascular endothelial cells compared to in situ tumors, and endothelial cells in metastasis show significant senescence. Senescent endothelial cells in metastatic tumors showed significant Krüppel-like factor 4 (KLF4) upregulation, overexpression of KLF4 in normal endothelial cells induced senescence, and knockdown of KLF4 in senescent endothelium inhibited senescence, suggesting that KLF4 is a driver gene for endothelial senescence. KLF4-induced endothelial senescence drove tumor cell migration through a senescence-associated secretory phenotype (SASP), of which the most important component of the effector was CXCL12 (C-X-C motif chemokine ligand 12), and participated in the composition of the immunosuppressive microenvironment. CONCLUSION: This study provides an undesirable insight of senescent endothelial cells in promoting UM metastasis.

A silicon diode-based optoelectronic interface for bidirectional neural modulation.

The development of advanced neural modulation techniques is crucial to neuroscience research and neuroengineering applications. Recently, optical-based, nongenetic modulation approaches have been actively investigated to remotely interrogate the nervous system with high precision. Here, we show that a thin-film, silicon (Si)-based diode device is capable to bidirectionally regulate in vitro and in vivo neural activities upon adjusted illumination. When exposed to high-power and short-pulsed light, the Si diode generates photothermal effects, evoking neuron depolarization and enhancing intracellular calcium dynamics. Conversely, low-power and long-pulsed light on the Si diode hyperpolarizes neurons and reduces calcium activities. Furthermore, the Si diode film mounted on the brain of living mice can activate or suppress cortical activities under varied irradiation conditions. The presented material and device strategies reveal an innovated optoelectronic interface for precise neural modulations.

A Bionic Flapping Magnetic-Dipole Resonator for ELF Cross-Medium Communication.

Extremely low-frequency (ELF) electromagnetic (EM) waves adeptly propagate in harsh cross-medium environments, overcoming rapid decay that hinders high-frequency counterparts. Traditional antennas, however, encounter challenges concerning size, efficiency, and power. Here, drawing inspiration from nature, we present a groundbreaking piezo-actuated, bionic flapping-wing magnetic-dipole resonator (BFW-MDR), operating in the electro-mechano-magnetic coupling mechanism, designed for efficient ELF EM wave transmission. The unique rigid-flexible hybrid flapping-wing structure magnifies rotation angles of anti-phase magnetic dipoles by tenfold, leading to constructive superposition of emitted magnetic fields. Consequently, the BFW-MDR exhibits a remarkable quality factor of 288 and an enhanced magnetic field emission of 514 fT at 100 meters with only 6.9 mW power consumption, surpassing traditional coil antennas by three orders of magnitude. The communication rate is doubled by the ASK+PSK modulation method. Its robust performance in cross-medium communication, even amidst various interferences, underscores its potential as a highly efficient antenna for underwater and underground applications.

Ternary superhydrides for high-temperature superconductivity at low pressures.

Focusing on the ternary hydrides, the new hope of Room-Temperature Superconductivity, this perspective delves into the research background, highlights current challenges, and illuminates promising avenues for future studies.

The impact of benzoic acid and lactic acid on the treatment efficiency and microbial community in the sulfur autotrophic denitrification process.

Nitrate poses a potential threat to aquatic ecosystems. This study focuses on the sulfur autotrophic denitrification mechanism in the process of water culture wastewater treatment, which has been successfully applied to the degradation of nitrogen in water culture farm effluents. However, the coexistence of organic acids in the treatment process is a common environmental challenge, significantly affecting the activity of denitrifying bacteria. This paper aims to explore the effects of adding benzoic acid and lactic acid on denitrification performance, organic acid removal rate, and microbial population abundance in sulfur autotrophic denitrification systems under optimal operating conditions, sulfur deficiency, and high hydraulic load. In experiments with 50 mg·L-1 of benzoic acid or lactic acid alone, the results show that benzoic acid and lactic acid have a stimulating effect on denitrification activity, with the stimulating effect significantly greater than the inhibitory effect. Under optimal operating conditions, the average denitrification rate of the system remained above 99%; under S/N = 1.5 conditions, the average denitrification rate increased from 88.34% to 91.93% and 85.91%; under HRT = 6 h conditions, the average denitrification rate increased from 75.25% to 97.79% and 96.58%. In addition, the addition of organic acids led to a decrease in microbial population abundance. At the phylum level, Proteobacteria has always been the dominant bacterial genus, and its relative abundance significantly increased after the addition of benzoic acid, from 40.2% to 61.5% and 62.4%. At the genus level, Thiobacillus, Sulfurimonas, Chryseobacterium, and Thermomonas maintained high population abundances under different conditions. PRACTITIONER POINTS: Employing autotrophic denitrification process for treating high-nitrate wastewater. Utilizing organic acids as external carbon sources. Denitrifying bacteria demonstrate high utilization efficiency towards organic acids. Organic acids promote denitrification more than they inhibit it. The promotion is manifested in the enhancement of activity and microbial abundance.