Enzymatic Degradation toward Herbicides: The Case of the Sulfonylureas.

Commercial herbicides, particularly sulfonylureas, are used worldwide and pose a significant challenge to environmental sustainability. The efficient degradation of sulfonylurea herbicides is critical. SulE, an esterase isolated from the bacterial strain Hansschlegelia zhihuaiae S113, shows degradation activity toward sulfonylurea herbicides. However, the detailed catalytic mechanism remains vague to a large extent. Herein, we decipher the SulEP44R-catalyzed degradation mechanism of sulfonylurea herbicides using hybrid quantum mechanics and molecular mechanics approaches. Our results show that the degradation of sulfonylureas catalyzed by SulEP44R involves four concerted elementary steps. The rate-determining step has an energy barrier range of 19.7-21.4 kcal·mol-1, consistent with the experimentally determined range of 16.0-18.0 kcal·mol-1. Distortion/interaction analysis demonstrates that active-site amino acids play a vital role in the enzymatic catalytic efficacy. The unique architecture of SulEP44R's active site can serve as an excellent template for designing artificial catalysts. Key structural and charge parameters affecting catalytic activity were systematically screened and identified. Based on the elucidated degradation mechanism, several new herbicides with both high herbicidal activity and biodegradability were developed with the aid of a high-throughput strategy. Our findings may advance the application of sulfonylurea herbicides within the framework of environmental sustainability.

Role of chitin synthases CHS1 and CHS2 in biosynthesis of the cyst wall of Cryptocaryon irritans.

Cryptocaryon irritans, a protozoan parasite that infects marine fish, is characterized by a complex life cycle that includes a cyst-forming reproductive phase. However, the composition of the cyst wall and mechanism of its formation remain unclear. In this study, we identified chitin as a key component of the cyst wall using calcofluor white and wheat germ agglutinin, with Fourier-transform infrared spectroscopy confirming its ß-form structure. Two chitin synthase genes, CHS1 and CHS2, were identified as being expressed throughout the life cycle and show close phylogenetic relationships with chitin synthase from ciliates. Incubation with specific anti-CHS1 and -CHS2 antibodies significantly reduced both the thickness and chitin content of the cyst wall, highlighting the critical role of these enzymes in chitin biosynthesis. Treatment with benzoylureas, which inhibit chitin synthesis, caused thinning of the cyst wall and downregulation of CHS gene expression, resulting in an 84 % reduction in the hatching rate after treatment with 0.01 mM CuSO4 compared with control tomonts. Western blot analysis demonstrated that recombinant CHS proteins are immunogenic, and tomonts from CHS-immunized grouper exhibited reduced size. These findings bridge a crucial knowledge gap in understanding of the C. irritans cyst wall and highlight promising targets for infection prevention and control strategies.

Efficacy and safety of camrelizumab-based comprehensive treatment for non-small cell lung cancer: a systematic review and meta-analysis.

Background: Many studies show that camrelizumab combination therapy can significantly improve progression-free survival (PFS) and overall survival (OS) in non-small cell lung cancer (NSCLC). However, the time of camrelizumab to market is short, and there is no systematic evaluation of camrelizumab-based comprehensive treatment of NSCLC. Objectives: To systematically evaluate the efficacy and safety of camrelizumab in comprehensively treating NSCLC. Design: A systematic review and meta-analysis. Data sources and methods: Databases, including PubMed, Web of Science, Embase, and Cochrane, were searched by computer before August 2023 based on Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, and reports on the efficacy and safety of camrelizumab-based treatment for NSCLC were collected, and RevMan 5.4 software was employed for meta-analysis finally. Results: Totally, 5 RCTs, 2 cohort studies, and 12 single-arm studies were included. The meta-analysis results revealed that, compared with the treatment without camrelizumab, the camrelizumab-based combination treatment considerably extended the OS (hazard ratio (HR) = 0.60, 95% confidence interval (CI): (0.44-0.82), p < 0.01), PFS (HR = 0.42, 95% CI: (0.28-0.63), p < 0.01), and event-free survival (EFS) (HR = 0.55, 95% CI: (0.44-0.68), p < 0.01). The median objective response rate in single-arm studies was 41% (95% CI: 28%-53%), and the disease control rate was 84% (95% CI: 78%-89%). Furthermore, in terms of the occurrence of grades 3-5 adverse events, the incidence of neutropenia was lower in the camrelizumab combination group than in the control group, while the incidence of leukopenia and rash was higher than in the combination group, and no significant difference was revealed in the incidence of other adverse events. Among single-arm studies, the incidence of grades 3-5 adverse events did not exceed 10%. Conclusion: Treatment combined with camrelizumab can effectively prolong OS, PFS, and EFS in NSCLC patients with good safety, camrelizumab combined with chemotherapy is an effective treatment option for NSCLC patients.

Pore modulation of single atomic Fe sites for ultrafast Fenton-like chemistry with amplified electron migration oxidation.

The limited interaction between pollutants, oxidants, and the surface catalytic sites of single atom catalysts (SACs) restricts the water decontamination effectiveness. Confining catalytic sites within porous structures enables the localized enrichment of reactants for optimized reaction kinetics, while the specific regulatory mechanisms remain unclear. Herein, SACs with porous modification significantly improves the utilization of peroxymonosulfate (PMS) and pollutant degradation activity. Confining catalytic sites in porous structure effectively reduces the mass transfer distance between radicals (SO4•- and •OH) and pollutants, thereby improving reaction performance. Pore modulation changes the surface electronic structure, leading to a significant improvement in the electron migration process. The system shows significant potential in effectively oxidizing various common emerging pollutants, and exhibits robust resistance to interference from environmental matrices. Moreover, a quantitative evaluation using life cycle assessment (LCA) indicates that the pFe-SAC/PMS system showcases superior environmental importance and practicality.

Selective elimination of organic pollutants and analysis of effects and novel mechanisms of aged microplastics on wavelength-dependent UV-LED/H2O2 system.

The selective removal of organic pollutants and potential impact of aged microplastics (MPs) as emerging pollutants in wavelength-dependent UV-LED/H2O2 system are not fully understood. This study found that cefalexin (CFX) degradation efficiency in UV-LED alone system was highly correlated with its UV molar absorbance (R2=0.994), while in UV-LED/H2O2 system, it was correlated with ·OH yield (R2=0.991) across various wavelengths. Quantitative structure-activity relationship (QSAR) analysis showed selective degradation of six pollutants based on their e--donating capabilities (R2=0.748-0.916). The coexistence of aged MPs, introducing C-O/C=O groups and rearranging their surface e-, potentially affected the elimination efficiency of CFX. Aged polystyrene (PS) decreased the degradation efficiency of CFX by shorting the O-O bond length (lO-O) in H2O2 and capturing e- from H2O2, whereas aged polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC) had negligible effects as the lO-O elongation balanced the e--donating effect of H2O2. Additionally, phenol released from aged PS, with strong nucleophilicity, competing with CFX for ·OH, further decreasing CFX degradation efficiency. This study provides valuable insights into organic pollutant selective removal and reveals a novel inhibitory mechanism of aged PS on the performance of UV-LED/H2O2 technology.

Safety analysis of quinolones use in minors-based on the FAERS database.

Objective: This study utilizes the FDA Adverse Event Reporting System (FAERS) to investigate adverse drug event (ADE) signals linked to quinolones use (ciprofloxacin, moxifloxacin, levofloxacin, ofloxacin) in minors, offering insights for clinical use. Methods: Minors were categorized into four age groups. ADE reports for these quinolones from the first quarter of 2015 to the third quarter of 2023 were extracted from the FAERS database. Data analysis used reporting odds ratio (ROR) and the MHRA method. Results: Most ADE cases in minors involved ciprofloxacin (575)and levofloxacin (477). In the infant group, various injury, poisoning, and procedural complication events were more frequently associated with ciprofloxacin, levofloxacin, and moxifloxacin (19.83%, 31.25%, and 100.00%, respectively). In the preschool children group, psychiatric disorders were more frequently reported with levofloxacin and ofloxacin use (59.00% and 47.62%, respectively). Ocular disorders were notably associated with moxifloxacin in the children group (62.50%), In the adolescent group, more gastrointestinal diseases occurred with ciprofloxacin (12.96%). Conclusion: ADE occurrence with quinolones in minors varies by age. Strict adherence to indications, rational use, avoiding prolonged use, and monitoring for short-term reactions are essential. Enhanced monitoring of interactions and drug education are crucial to reducing ADE.

Safety analysis of fluoroquinolone drugs in elderly patients over 65 based on FAERS.

OBJECTIVE: This study investigates adverse drug event (ADE) reports from the FAERS related to FQs drugs in patients aged 65 and older. The findings aim to guide the rational clinical use of these drugs in elderly patients. METHODS: We employed Reporting Odds Ratio (ROR) and Proportional Reporting Ratio (PRR) methods to analyze ADE reports for the representative FQ drugs from Q1 2015 to Q4 2023, covering 36 quarters. RESULTS: The analysis identified 6883 ADE cases for ciprofloxacin, 5866 for levofloxacin, 1498 for moxifloxacin, and 317 for ofloxacin. Moxifloxacin showed higher incidences of Cardiac disorders and Psychiatric disorders ADEs (4.01%, 23.11%). Ciprofloxacin and levofloxacin showed higher ADE rates in musculoskeletal and connective tissue diseases (20.18% and 26.97%) compared to moxifloxacin (3.62%) and ofloxacin (9.25%). Additionally, moxifloxacin and ofloxacin showed higher ADE rates for eye disorders (10.61% and 15.03%). CONCLUSION: Different FQs exhibit varying ADE profiles across cardiovascular, vascular and lymphatic, renal and urinary, psychiatric, musculoskeletal and connective tissue, and ocular systems. Patients with underlying systemic diseases should avoid FQs with higher ADE risks for their conditions. Personalized medication plans for elderly patients should also be strengthened.

Nanocarrier-based drug delivery system with dual targeting and NIR/pH response for synergistic treatment of oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is highly heterogeneous and aggressive, but therapies based on single-targeted nanoparticles frequently address these tumors as a single illness. To achieve more efficient drug transport, it is crucial to develop nanodrug-carrying systems that simultaneously target two or more cancer biomarkers. In addition, combining chemotherapy with near-infrared (NIR) light-mediated thermotherapy allows the thermal ablation of local malignancies via photothermal therapy (PTT), and triggers drug release to improve chemosensitivity. Thus, a novel dual-targeted nano-loading system, DOX@GO-HA-HN-1 (GHHD), was created for synergistic chemotherapy and PTT by the co-modification of carboxylated graphene oxide (GO) with hyaluronic acid (HA) and HN-1 peptide and loading with the anticancer drug doxorubicin (DOX). Targeted delivery using GHHD was shown to be superior to single-targeted nanoparticle delivery. NIR radiation will encourage the absorption of GHHD by tumor cells and cause the site-specific release of DOX in conjunction with the acidic microenvironment of the tumor. In addition, chemo-photothermal combination therapy for cancer treatment was realized by causing cell apoptosis under the irradiation of 808-nm laser. In summary, the application of GHHD to chemotherapy combined with photothermal therapy for OSCC is shown to have important potential as a means of combatting the low accumulation of single chemotherapeutic agents in tumors and drug resistance generated by single therapeutic means, enhancing therapeutic efficacy.

The Synergistic Inhibitory Effect of Combination Drug Treatment of Enteromorpha Prolifera Polysaccaharide and Doxorubicin Hydrochloride on A549 Cell.

BACKGROUND: As a common drug for tumor therapy, doxorubicin hydrochloride (DOX) is not yet widely used as a clinical solution. This is due to its toxicity and potential drug resistance. OBJECTIVE: This study investigated the inhibitory effect of enteromorpha prolifera polysaccaharide (EPP) combined with doxorubicin hydrochloride (DOX) on A549 cells, which fall into the cell line of human non-small cell lung cancer (NSCLC). It also explained the attenuated and synergistic effect of enteromorpha acid polysaccharide along with its synergistic effect on DOX. METHODS: To evaluate the proliferation inhibitory effect of EPP, DOX and both combined, we monitored cell growth curve and morphology using the real-time cell function analysis and imaging system-xCELLigence RTCA eSight system (eSight system). Flow cytometry was used to monitor cell apoptosis rate and cell cycle distribution. Mitochondrial function was tested by the energy metabolism analysis system. RESULTS: EPP could work with DOX to inhibit the proliferation of A549 cells. Growth curve showed that when 0.4 mg/mL of EPP was mixed with 0.2 µg/mL of DOX for 24 h, the mixure liquid had a significant inhibitory effect on the proliferation of A549 cells (p < 0.0001). The cells had lower cell adhesiveness, shrinking cell membrane, cytoplasmic aggregation, and hyperchromatic nuclei. According to the flow cytometry results, the combined drug of EPP and DOX could significantly increase the apoptosis rate of A549 cells (p < 0.0001), and block the cell cycle in the G1-S phase. Based on the results of the real-time energy metabolism, we found that the combined drug could significantly reduce A549 cells' ATP production rate and inhibit their mitochondrial respiratory function. CONCLUSIONS: The combination of EPP and DOX can block cell cycle, inhibit cell mitochondrial function, promote cell apoptosis, and enhance the killing ability of DOX on tumor cells. This study supports the antitumor activity of enterococcus acid polysaccharide and provides insights on reducing doxorubicin toxicity and drug resistance. It holds great significance for applying traditional Chinese natural medicine in clinical disease treatment.

Sorption/desorption and degradation of long- and short-chain PFAS by anion exchange resin and UV/sulfite system.

A combined sorption/desorption and UV/sulfite degradation process was investigated for achieving efficient elimination of PFAS from water. Two gel-type resins, Purolite A532E and A600, and one macroporous resin, Purolite A860, were firstly tested for the sorption of individual PFPrA, PFHxA, PFOA, PFOS, and GenX at different concentrations. Sorption data and density functional theory (DFT) calculations revealed that electrostatic interactions predominated for short-chain PFAS sorption and hydrophobic interactions played a more significant role for long-chain PFAS than for short-chain PFAS. A600 and A860 were selected for desorption tests with 0.025% NaOH, 5% NaCl, and 5% NH4Cl solution with or without 20% ethanol (EtOH) due to their high sorption capacity for all target PFAS. The mixture of 5% NH4Cl and 20% EtOH as the desorption solution typically showed the highest desorption efficiency. PFOS was the most resistant for desorption but its desorption could be enhanced by stronger mixing conditions (in 5% NaCl + 20% EtOH). Direct degradation of studied PFAS in the desorption solution (0.025% NaOH, 5% NaCl, and 5% NH4Cl) by UV/sulfite achieved 97.6-100% degradation and 46.6-86.1% defluorination. EtOH hindered degradation and thus should be separated from the water before UV/sulfite degradation.

[Research status and prospect of the application of artificial intelligence in the acupuncture and moxibustion field based on bibliometric].

To explore the research hotspot, development trend and existing problem of artificial intelligence (AI) application in the field of acupuncture and moxibustion by using bibliometric method. Relevant articles of AI application in the field of acupuncture and moxibustion published in CNKI, Wanfang, VIP, PubMed and Web of Science from the database establishment to September 17, 2023 were searched. Excel 2019, CiteSpace 6.2.R4 and VOSviewer 1.6.19 were used to draw visual map of the number of publication, authors, research institutions and keywords, and further analyzed the research hotspot and trend. A total of 443 Chinese articles and 68 English articles were included. The number of annual publication of Chinese articles showed an overall increasing trend, while the number of publication of English articles was less, with a growing trend from 2020. Keywords analysis showed that "Machine learning", "neural network", "deep learning", "data mining", "robot" and other AI technologies were developing around acupuncture and moxibustion diagnosis and treatment of disease, efficacy prediction, teaching and intelligent equipment development. However, the research on the application of AI in the field of acupuncture and moxibustion is in the preliminary stage of development, and in the future, it is necessary to strengthen the communication and cooperation among the teams, to further explore the AI system in line with the characteristics of acupuncture and moxibustion diagnosis and treatment, and to promote the development of the digitalisation, intellectualisation and industrialisation of acupuncture and moxibustion.

BhrPETase catalyzed polyethylene terephthalate depolymerization: A quantum mechanics/molecular mechanics approach.

Polyethylene terephthalate (PET) is a widely used material in our daily life, particularly in areas such as packaging, fibers, and engineering plastics. However, PET waste can accumulate in the environment and pose a great threat to our ecosystem. Recently enzymatic conversion has emerged as an efficient and green strategy to address the PET crisis. Here, using a theoretical approach combining molecular dynamics simulation and quantum mechanics/molecular mechanics calculations, the depolymerization mechanism of the thermophilic cutinase BhrPETase was fully deciphered. Surprisingly, unlike the previously studied cutinase LCCICCG, our results indicate that the first step, catalytic triad assisted nucleophilic attack, is the rate-determining step. The corresponding Boltzmann weighted average energy barrier is 18.2 kcal/mol. Through extensive comparison between BhrPETase and LCCICCG, we evidence that key features like charge CHis@N1 and angle APET@C1-Ser@O1-His@H1 significantly impact the depolymerization efficiency of BhrPETase. Non-covalent bond interaction and distortion/interaction analysis inform new insights on enzyme engineer and may aid the recycling of enzymatic PET waste. This study will aid the advancement of the plastic bio-recycling economy and promote resource conservation and reuse.

Enhancing the amination activity of meso-diaminopimelate dehydrogenase from Symbiobacterium thermophilum by modifying the crucial residue His154 for deamination.

During the deamination and amination processes of meso-diaminopimelate dehydrogenase (meso-DAPDH) from Symbiobacterium thermophilum (StDAPDH), residue R71 was observed to display distinct functions. H154 has been proposed as a basic residue that facilitates water molecules to attack the D-chiral carbon of meso-DAP during deamination. Inspired by the phenomenon of R71, the effects of H154 during deamination and amination were investigated in this study with the goal of enhancing the amination activities of StDAPDH. Single site saturation mutagenesis indicated that almost all of the H154 mutants completely lost their deamination activity towards meso-DAP. However, some H154 variants showed enhanced kcat/Km values towards pyruvic acid and other bulky 2-keto acids, such as 2-oxovaleric acid, 4-methyl-2-oxopentanoic acid, 2-ketobutyric acid, and 3-methyl-2-oxobutanoic acid. When combined with the previously reported W121L/H227I mutant, triple mutants with significantly improved kcat/Km values (2.4-, 2.5-, 2.5-, and 4.0-fold) towards these 2-keto acids were obtained. Despite previous attempts, mutations at the H154 site did not yield the desired results. Moreover, this study not only recognizes the distinctive impact of H154 on both the deamination and amination reactions, but also provides guidance for further high-throughput screening in protein engineering and understanding the catalytic mechanism of StDAPDH.

Multilayer Porous Fe/Co-N-MWCNT Electrocatalyst For Rechargeable Zinc-Air Batteries.

The design of efficient, stable, low-cost non-precious metal-based electrocatalysts with enhanced oxygen reduction reaction (ORR) activity has garnered significant attention in the scientific community. This study introduces a novel electrocatalyst, Fe/Co-N-MWCNT, synthesized through the in-situ growth of ZIF-8 and Fe/Co-Phen on multi-walled carbon nanotubes (MWCNTs), followed by pyrolysis at varying temperatures to optimize its properties. The inclusion of Fe and Co during the pyrolysis process facilitated the creation of metal active sites and Fe-Co, enhancing electron transfer and ORR activity. Compared to Pt/C (E1/2=0.854 V, JL=4.90 mA cm-2), Fe/Co-N-MWCNT exhibited a similar half-wave potential (E1/2=0.812 V) and an improved limiting current density (JL=5.37 mA cm-2). Moreover, Fe/Co-N-MWCNT displayed remarkable stability, showing only a 7 mV negative shift in E1/2 after 2000 cycles. Ampere response testing indicated a current decay of only 7.8 % for Fe/Co-N-MWCNT after 10000 s, while Pt/C experienced a decay of about 18.4 %. The exceptional catalytic stability of Fe/Co-N-MWCNT positions it as a promising candidate for rechargeable zinc-air batteries, attributed to its high pyridinic nitrogen content, unique structure, and abundant metal active sites.

Comparison of dynamic hip screw with anti-rotation screw and femoral neck system internal fixation for the treatment of garden II-IV type femoral neck fractures.

BACKGROUND: Femoral neck fractures, which are fractures occurring from the femoral head to the base of the femoral neck, are prevalent in the elderly population. With the progression of societal aging, the incidence of femoral neck fractures has been steadily increasing, making it a significant global issue that urgently needs to be addressed. OBJECTIVE: To compare the efficacy and safety of dynamic hip screw (DHS) with anti-rotation screw and femoral neck system (FNS) internal fixation for the treatment of Garden II-IV type femoral neck fractures. METHODS: A total of 90 patients with Garden II-IV type femoral neck fractures were randomly assigned to either the control group (n= 45) treated with DHS and anti-rotation screw or the experimental group (n= 45) treated with FNS. Surgical outcomes, including incision size, blood loss, operation time, fluoroscopy frequency, and fracture healing time, were compared. Postoperative complication rates, reoperation rates, Harris scores, and visual analogue scale (VAS) scores were also assessed. RESULTS: The experimental group demonstrated significantly reduced incision length, blood loss, operation time, and fluoroscopy frequency compared to the control group (P< 0.01). No significant differences were observed in fracture healing time, Garden classification, or fracture reduction outcomes between the two groups (P> 0.05). At 6 months post-treatment, both groups showed significant improvements in Harris scores and VAS scores compared to pre-treatment (P< 0.05), with no significant differences between the groups (P> 0.05). The rates of internal fixation failure, nonunion, and avascular necrosis of the femoral head, as well as overall incidence of postoperative complications and reoperation rates, showed no significant differences between the two groups (P> 0.05). CONCLUSIONS: Both DHS with anti-rotation screw and FNS internal fixation demonstrated comparable efficacy and safety profiles in the treatment of Garden II-IV type femoral neck fractures. The experimental group showed advantages in terms of reduced incision length, blood loss, operation time, and fluoroscopy frequency, while maintaining similar clinical outcomes and complication rates.

Prolonged administration of the granisetron transdermal delivery system reduces capecitabine plus oxaliplatin regimen induced nausea and vomiting.

OBJECTIVE: To evaluate the safety and efficacy of the granisetron transdermal delivery system (GTDS) combined with Dexamethasone for preventing chemotherapy-induced nausea and vomiting (CINV) in patients receiving Capecitabine plus Oxaliplatin (CapeOX) therapy. DESIGN: Open-label, prospective, multi-center phase II trial. SETTING: Three institutions. PARTICIPANTS: Fifty-four patients scheduled to receive CapeOX chemotherapy. INTERVENTIONS: Participants received GTDS (3.1 mg applied to the upper arm 48 h before chemotherapy, replaced on day 5, and discarded on day 12) and Dexamethasone. MAIN OUTCOME MEASURES: The primary endpoint was the complete control rate of CINV. Secondary endpoints included the duration of delayed complete control, complete control rate in the acute phase, safety, and quality of life. RESULTS: The complete control rate for delayed CINV over the entire period (25-480 h) was 72.7% (95% CI 0.57-0.88). The duration of delayed complete control was 17.2 ± 4.5 days, with 51.5% of patients experiencing no nausea during the delayed phase. The complete control rate in the acute phase was 81.8% (95% CI 0.69-0.95). No serious adverse events related to the antiemetic regimen were reported. CONCLUSION: Prolonged administration of GTDS is safe and effective for preventing CINV in patients with gastrointestinal malignancies treated with CapeOX. TRIAL REGISTRATION: ClinicalTrials.gov registry (NCT05325190); registered on October 10, 2021.

Biotic/abiotic transformation mechanisms of phenanthrene in iron-rich constructed wetland under redox fluctuation.

Iron-rich constructed wetlands (CWs) could promote phenanthrene bioremediation efficiently through biotic and abiotic pathways, which have gained increasing attention. However, the biotic/abiotic transformation mechanisms of trace organic contaminants in iron-rich CW are still ambiguous. Herein, three CWs (i.e., CW-A: Control; CW-B: Iron-rich CW, CW-C: Iron-rich CW + tidal flow) were constructed to investigate the transformation mechanisms of phenanthrene through Mössbauer spectroscopy and metagenomics. Results demonstrated CW-C achieved the highest phenanthrene removal (94.0 %) and bacterial toxicity reduction (92.1 %) due to the optimized degradation pathway, and subsequently achieved the safe transformation of phenanthrene. Surface-bound/low-crystalline iron regulated hydroxyl radical (·OH) production predominantly, and its utilization was promoted in CW-C, which also improved electron transfer capacity. The enhanced electron transfer capacity led to the enrichment of PAH-degrading microorganisms (e.g., Thauera) and keystone species (Sphingobacteriales bacterium 46-32) in CW-C. Additionally, the abundances of phenanthrene transformation (e.g., EC:1.14.12.-) and tricarboxylic-acid-cycle (e.g., EC:2.3.3.1) enzyme were up-regulated in CW-C. Further analysis indicated that the safe transformation of phenanthrene was mainly attributed to the combined effect of abiotic (·OH and surface-bound/low-crystalline iron) and biotic (microbial community and diversity) mechanisms in CW-C, which contributed similarly. Our study revealed the essential role of active iron in the safe transformation of phenanthrene, and was beneficial for enhanced performance of iron-rich CW.