Antioxidants
·
2025
·Vol. 14
·期 8
·914
·
IF 6.6
Pengxin Jiang,Kangping Liu,Yanan Cui,Puyu Liu,Xutao Wang,Zijuan Hou,Jiamei Cui,Ning Chen,Jinghui Fan,Jianguo Li,Yuzhu Zuo,Yan Li
EnterotoxigenicEscherichia coli(ETEC) leads to severe diarrhea in piglets. Naringenin (Nar), a natural flavonoid compound, is known for its antibacterial and anti-antioxidant properties. However, the protective effects of Nar against ETEC-induced diarrhea have not been reported yet. This study investigated the protective mechanisms of Nar against ETEC infection in porcine intestinal epithelial cells (IPEC-J2). ETEC infection induced oxidative stress and ferroptosis in IPEC-J2 cells by elevating intracellular iron content and ROS accumulation, increasing MDA levels, downregulating SOD activity and GPX4 expression, and upregulating the transcription of CHAC1 and SLC7A11. In contrast, Nar suppressed ETEC-induced ferroptosis of IPEC-J2 cells by inhibiting the SLC7A11/GPX4 pathway. Specifically, Nar mitigated mitochondrial damage, reduced intracellular iron levels and ROS accumulation, and ultimately reversed the oxidative stress. Network pharmacology and molecular docking identified heat-shock protein 90 (HSP90) as a potential target of Nar. Overexpression and knockdown experiments revealed that ETEC-induced ferroptosis was mediated by upregulation of HSP90, while the protective effects of Nar against ETEC-induced ferroptosis were dependent on the downregulation of HSP90. In conclusion, Nar targets host HSP90 to protect IPEC-J2 cells from ferroptosis caused by ETEC infection. This study demonstrates that Nar is a potent antioxidant natural compound with potential for preventing ETEC-induced intestinal damage.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2025
·
IF 8
Zhengfeng Guo,Tingting Zhang,Hao Yang,Xiaolin Zhu,Siyuan Lu,Anjie Chen,Mingyu Fan,Jiao Qu
In aquatic environments, antibiotics degrade into byproducts, potentially enhancing bacterial resistance. However, the specific mechanisms by which these byproducts induce bacterial resistance remain elusive. This study conducted experimental evolution experiments to explore how E. coli adapts to tetracycline (TC) and its primary degradation products—anhydrotetracycline (ATC), epitetracycline (ETC), and 4-epianhydrotetracycline (EATC)—through evolution experiments. Prolonged exposure to TC and its byproducts significantly increased frequency of resistant mutants in E. coli ATCC25922, with a maximum 10 6 -fold increase. Resistant mutants exhibited markedly elevated minimum inhibitory concentrations (MICs) for TC, ampicillin (AMP), and ciprofloxacin (CIP), indicating multidrug resistance. Transcriptomic analysis showed that the antibiotic resistance phenotype could be related to enhanced target protection, metabolic adaptations, and reduced membrane permeability. The induction pathways between TC and its byproducts were distinct. Specifically, TC 20d (where TC 20d represents the mutants collected after 20 days of continuous exposure to TC) was associated with more alterations in ribosome-associated genes, which was correlated with an enhanced defensive response as shown by the data. Moreover, variations in energy metabolism gene expression suggest a robust metabolic defense in ATC 20d and ETC 20d . When TC and its byproducts—ATC, ETC, and EATC—act together, they induce antibiotic resistant mutants at rates of 29.8 %, 18.9 %, 18.3 %, and 31.9 %, respectively. This study provides a descriptive overview of the possible adaptive mechanisms and pathways that may be involved in antibiotic resistance due to environmental exposure.
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2017
·Vol. 93
·期 6
·1648-1654
·
IF 3.135
Jun Chen,Shuang Xu,Hai Yang,Chaktong Au,Shuanghong Tian,Ya Xiong
BACKGROUND This study aims to reveal the potential of using heterogeneous catalytic ozonation processes (HCOP) in water disinfection and provide a direction to tailor the catalytic activity by crystal facet engineering. Four kinds of MgO nanocrystals individually with exposure of (111), (200), (110) and (100) facets were prepared and used. RESULTS It is found that MgO functions as a bactericide as well as a catalyst for ozonation. The catalytic activity of MgO nanocrystals decreases in the order MgO(111) > MgO(200) > MgO(110) > MgO(100). The apparent first-order inactivation rate (k ap ) fitted by the Hom model of MgO(111)/O 3 is 2.56 min -1 , which is 32.0 and 3.5 times that of single ozonation and classic MgO(100)/O 3 . It is confirmed by scavenger studies that •OH mainly works in MgO(111)/O 3 while more direct ozonation occurs in other cases. Some O 2 •− are also detected in the presence of MgO. With the attack of these reactive oxidation species, cell membranes were damaged and intracellular components were released, leading to the death of Escherichia coli . CONCLUSION These results indicate that HCOP is a promising technology for water disinfection, and crystal facet engineering is an effective strategy to enhance the catalytic performance. © 2017 Society of Chemical Industry
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Reaction Kinetics Mechanisms and Catalysis
·
2024
·Vol. 137
·期 2
·1225-1238
·
IF 1.7
Wang Wanchun,Chi Yangxu,Sun Jiahong,Zhou Feng,Zhan Su
In this work, Ag/CuBi 2 O 4 composite photocatalyst films with excellent photocatalytic sterilization properties were prepared by photodeposition. The photocatalytic activity of silver-modified CuBi 2 O 4 (Ag/CuBi 2 O 4 ) under the photocatalytic-Fenton coupling system was verified by its inactivation rate of Escherichia coli in seawater. The results showed that the photocatalytic sterilizing performance of CuBi 2 O 4 loaded with Ag in the presence of trace amounts of H 2 O 2 was significantly improved. 15Ag/CuBi 2 O 4 possessed the optimal photocatalytic activity, and its sterilizing rate in 30 min could reach 96.6%. Its sterilization rate in 30 min could reach 96.6%, which is about 70% higher than that of pure CuBi 2 O 4 . Meanwhile, the mechanism of the enhanced sterilization performance of Ag/CuBi 2 O 4 in the photocatalytic-Fenton coupled system was investigated. Firstly, according to the electrochemical results, the loading of Ag can significantly improve the charge separation efficiency of CuBi 2 O 4 . And promotes the conversion of H 2 O 2 to hydroxyl radicals(·OH); Secondly, the valence band potential of 15Ag/CuBi 2 O 4 is more positive than that of CuBi 2 O 4 , which suggests that Ag loading can enhance the oxidation of CuBi 2 O 4 cavities. Comprehensive radical trapping experiments demonstrate that ·OH and holes (h + ) are the main active species for inactivating Escherichia coli (E. coli). In this work, effective conversion of H 2 O 2 to ·OH in a wide spectral range was achieved by loading Ag nanoparticles on the surface of CuBi 2 O 4 , which provides a new idea for the development of photocatalytic-Fenton coupling technology and ballast water treatment. Graphical abstract
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Microorganisms
·
2026
·Vol. 14
·期 2
·327
·
IF 4.2
Ben Xu,Xiran Chen,Jinmei Chai,Yunlin Wei
Previous studies have demonstrated that catecholamines, including epinephrine (Epi), norepinephrine (NE), and dopamine (DA), function both as xenosiderophores for bacteria possessing dedicated transport channels and as potential quorum-sensing signaling molecules or regulatory factors. However, current research on the interactions between dopamine and bacteria remains relatively limited. In this study, treatment ofEscherichia coli(E. coli) ATCC 11303 with a specific concentration of dopamine resulted in a 33.63% increase in the maximum growth biomass, a 47.32% enhancement in biofilm formation, a 24.60% increase in protease activity, a 68.81% improvement in swimming motility, and increases of 33.77% and 47.67% in chemotaxis and swarming motility, respectively. Transcriptome analysis revealed that dopamine promoted the expression of numerous iron uptake-related genes, while biofilm formation-related genes and virulence genes were concomitantly upregulated. High-performance liquid chromatography–mass spectrometry (HPLC-MS) and isotope ratio mass spectrometry (IRMS) analyses confirmed thatE. coliATCC 11303 can uptake dopamine, suggesting the existence of specific transport pathways. Multi-omics analysis revealed significant regulatory effects on metal ion transport, amino acid metabolism, purine metabolism, environmental adaptation, quorum sensing, two-component systems, and xylene degradation pathways. Dopamine may act as both a xenosiderophore and a signaling molecule, thereby modulating multiple critical physiological and biochemical processes and promoting bacterial growth. These findings provide valuable insights into the development of novel exogenous xenosiderophores and signaling modulators, advancing our understanding of microbial interactions with their host environment and contributing to the field of microbial endocrinology.
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BMC BIOTECHNOLOGY
·
2026
·
IF 4.8
Wang Yingying,Cao Meihui,Hu Mei,Xu Hengrui,Du Yafei,Sun Changxing,Kong Lingfei,Luo Yu,Liu Xiaoyu,Yang Jianming,Liang Bo
Background 3-Hydroxypropionic acid (3-HP) is a promising C3 platform chemical with wide industrial applications. However, its microbial production remains limited by insufficient intracellular malonyl-CoA availability and metabolic imbalance. Result In this study, we systematically engineered Escherichia coli for enhanced 3-HP biosynthesis. The malonate assimilation genes ( matB , smatPQM ) and 3-HP biosynthesis gene ( mcr ) were chromosomally integrated using CRISPR/Cas9, resulting in a plasmid-free, antibiotic-free strain (WYY04) that produced 21.97 mM 3-HP, 0.51-fold higher than the plasmid-based system. Further improvement was achieved by CRISPRi-mediated repression of fatty acid biosynthesis genes ( fabD , fabF ), increasing 3-HP titer by 66%. Introduction of a malonyl-CoA-responsive FapR/fapO biosensor enabled dynamic regulation of mcr expression, enhancing 3-HP production by 59%. Through all these above engineering, the 3-HP production of the strain WYY19 increased by 2.29 times compared to that of the plasmid-expressing system. Under optimized fermentation conditions, the final engineered strain WYY19 produced 42.22 g/L 3-HP with the specific productivity of 0.69 g/g and 0.46 g/L/h from glucose and malonate in fed-batch bioreactor. Conclusions This study demonstrates a robust, genetically stable, and scalable microbial platform for 3-HP biosynthesis.
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Cell Reports Medicine
·
2026
·
IF 14
Junhua Xie,Xi-jian Dai,Qiqiong Li,Wanyu Zhang,Xinke Nie,Haihua Ji,Xinyang Chen,Yuchen Wang,Jing Feng,Zhipeng Li,Qiong Liu,Jianxin Ye,Guangzhi Zhang,Shaoping Nie
Gut microbiota dysbiosis is a driving factor in Alzheimer’s disease (AD), yet the mechanisms behind remain elusive. Emerging evidence highlights that outer membrane vesicles (OMVs) are critical mediators of microbiota-host communication. Here, we observed a reduction in a gut probiotic Escherichia coli Nissle 1917 (EcN)-like strain in AD patients, and its levels are positively associated with cognitive ability. The EcN OMVs containing outer membrane protein A (OmpA) translocate to the brain, reshaping the dysregulated immune network. Specifically, EcN OMVs are internalized by glia and neurons, suppressing glial hyperactivation and restoring synaptic function, thereby reducing Aβ deposition and cognitive deficits. The results further show that OmpA plays an important role in vesicle trafficking and inflammatory pathways and may be the key regulator of inflammatory mediators in EcN OMVs, modulating astrocyte-microglia-neuron interactions and functionality. This work discloses the substantial therapeutic potential of the probiotic and its secreted OMVs in intervention and treatment of neurological disorders.
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JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY
·
2026
·
IF 3.1
Shijie Du,Shujing Yan,Muyasaer Aisana,Huan Xu,Hanjing Xue,Chunhong Zhong,Xiaoli Gao,Chunli Chen
20α-Hydroxyprogesterone (20α-DHP) is an endogenous progestogenic metabolite of progesterone, biosynthesized primarily through the catalytic action of 20α-hydroxysteroid dehydrogenase (20α-HSD). To screen for highly active 20α-HSDs, five enzymes derived from phylogenetically diverse species—human, orangutan, mouse, bovine, and porcine—were systematically evaluated using multiple sequence alignment, molecular docking, and molecular dynamics simulations. The corresponding genes were subsequently expressed heterologously in E. coli BL21(DE3), and activity screening identified the human-derived 20α-HSD as the superior candidate. Enzymatic characterization revealed maximal activity at pH 8.0 and 35°C, negligible sensitivity to metal ions, and high substrate affinity and catalytic efficiency. Expression conditions were further optimized, with 0.2 mM IPTG at 20°C for 20 h established as the optimal induction parameters. Systematic optimization of reaction parameters—including organic solvent types and optimal concentration of the organic solvent, catalytic time, NADPH concentration, and recombinase concentration —achieved a progesterone conversion rate of 66.75%. To minimize cofactor consumption and enhance process economics, a glucose dehydrogenase-mediated NADPH in situ regeneration system was constructed, sustaining a conversion rate of 64.62%. Scale-up to a 100 mL preparative reaction yielded a conversion rate of 60.83%. Following column chromatography purification, 20α-DHP was isolated in 45.36% yield with 95% purity, as confirmed by HPLC and ¹H NMR analyses. In summary, this study achieved the successful heterologous expression of 20α-HSD in E. coli and established an efficient, green, and highly selective biosynthetic route for 20α-DHP, providing a viable technical foundation for its potential industrial-scale production.
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INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS
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2026
·
IF 5
Lihe Zhang,Yongjuan Li,Yuhang Bao,Jie Feng,Runyu Chen,Wenjing Zhang,Yixuan Zhu,Liwen Zhang,Yin Zhang,Feng Liang,Huimin Chen,Xinhua Luo,Guoqiang Tan,Wu Wang
D-Cycloserine (DCS) is a broad-spectrum antibiotic used to treat drug-resistant tuberculosis. It exerts its antimicrobial effects by inhibiting a variety of pyridoxal 5′-phosphate (PLP)-dependent enzymes. Recent studies indicate that cycloserine targets cysteine desulfurases, which are essential for iron–sulfur (Fe–S) cluster biogenesis. However, the mechanistic details of its effect on Fe–S cluster assembly are unclear. In this study, we demonstrate that L-Cycloserine (LCS), but not its enantiomer DCS, inhibits the cysteine desulfurase activity of Escherichia coli ( E. coli ) IscS, resulting in impaired Fe–S cluster biosynthesis. Liquid chromatography-mass spectrometry (LC–MS) analysis showed that LCS converts the IscS-bound PLP cofactor into pyridoxamine 5′-phosphate (PMP). Importantly, LCS significantly inhibited the growth of the uropathogenic E. coli strain CFT073, and remained effective against experimentally-evolved DCS-resistant strains in synthetic human urine medium. Our work highlights Fe–S cluster biosynthesis as a novel antimicrobial target and proposes LCS as a promising alternative therapeutic agent to counteract DCS resistance.
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Metabolites
·
2026
·Vol. 16
·期 1
·62
·
IF 3.7
Qing Luo,Weihao Wang,Qingjing Huang,Chuan Wang,Lixiu Yan,Jun Kang,Jiamin Zhang,Jie Cheng
Background/Objectives: Caffeic acid is a hydroxycinnamic acid that has a wide range of applications in the medical field. The synthesis of caffeic acid using microbial fermentation technology is an environmentally friendly method. Methods: By engaging various enzymes, specifically 4-hydroxyphenylacetate 3-monooxygenase (HpaB), sourced from diverse bacterial strains, we successfully engineered a functional version of this enzyme withinEscherichia coli, enabling the production of caffeic acid. In addition to the two common tyrosine ammonia lyases (TAL) and HpaC, different combinations of HpaB demonstrated varying abilities in converting the substrate L-tyrosine into the desired product, caffeic acid. Results: Under shake-flask culture conditions, the highest yield of caffeic acid was achieved with an enzyme mixture containing HpaB fromEscherichia coli, reaching 75.88 mg/L. Enhancing the activity of the rate-limiting enzyme through engineering could potentially increase caffeic acid titer. This study aims to conduct a semi-rational design of HpaB through structure-based approaches to screen for mutants that can enhance the production of caffeic acid. Initially, the predicted three-dimensional structure of HpaB was generated using AlphaFold2, and subsequent analysis was conducted to pinpoint the critical mutation sites within the substrate-binding pocket. Five key amino acid residues (R113, Y117, H155, S210 and Y461) located in the vicinity of the flavin adenine dinucleotide binding domain in HpaB fromEscherichia colicould be instrumental in modulating enzyme activity. Subsequently, the mutant S210G/Y117A was obtained by iterative saturation mutagenesis, which increased the titer of caffeic acid by 1.68-fold. The caffeic acid titer was further improved to 2335.48 mg/L in a 5 L fermenter. The findings show that the yield of caffeic acid was significantly enhanced through the integration of semi-rational design and fermentation process optimization.
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TRENDS IN BIOTECHNOLOGY
·
2025
·
IF 14.9
Junjun Yan,Yunhong Chen,Yuyue Ma,Xue Yang,Yonghong Yao,Guoping Zhao,Yanfei Zhang
Ergothioneine (ERG) is a rare amino acid with diverse biological activities, making it valuable for applications in the food, cosmetics, and pharmaceutical industries. Compared with traditional extraction from edible fungi, microbial fermentation offers a more scalable alternative, but its feasibility is largely determined by production titer and cost. In this study, we developed a novel ERG biosynthesis strategy that eliminates the need for expensive methionine and cysteine supplementation during fermentation. By reconstructing a betaine-driven methyl supply system and an inorganic sulfur supply module in Escherichia coli , we engineered a highly efficient ERG-producing strain capable of utilizing betaine as a methyl donor and inorganic sulfur as a sulfur source. As a result, shake flask fermentations achieved an ERG titer of 456 ± 9 mg/l without exogenous methionine and cysteine supplementation. Further optimization strategies, including enhanced intracellular histidine synthesis, alleviation of methionine feedback inhibition, and improved ERG transport efficiency, increased the shake flask titer to 1.2 g/l, a 24-fold improvement over the initial strain. Scale-up in a 5-l fermenter further optimized fermentation conditions, yielding an ERG titer of 7.2 g/l. Thus, the metabolic engineering strategy described in this study provides a scalable and cost-effective platform for the industrial production of ERG and other methyl- and sulfur-containing natural products.
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ENGINEERING IN LIFE SCIENCES
·
2023
·Vol. 23
·期 6
·e2200125
·
IF 2.7
Da Chen,Yue-Sheng Dong,Yong-Ming Bao,Zhi-Long Xiu
Traditional technology of cell disruption has become one of the bottlenecks restricting the industrialization of genetic engineering products due to its high cost and low efficiency. In this study, a novel bioprocess of phage lysis coupled with salting-out extraction (SOE) was evaluated. The lysis effect of T7 phage on genetically engineered Escherichia coli expressing κ-carrageenase was investigated at different multiplicity of infection (MOI), meanwhile the phage and enzyme released into the lysate were separated by SOE. It was found that T7 phage could lyse 99.9% of host cells at MOI = 1 and release more than 90.0% of enzyme within 90 min. After phage lysis, 87.1% of T7 phage and 71.2% of κ-carrageenase could be distributed at the middle phase and the bottom phase, respectively, in the SOE system composed of 16% ammonium sulfate and 20% ethyl acetate (w/w). Furthermore, κ-carrageenase in the bottom phase could be salted out by ammonium sulfate with a yield of 40.1%. Phage lysis exhibits some advantages, such as mild operation conditions and low cost. While SOE can efficiently separate phage and intracellular products. Therefore, phage lysis coupled with SOE is expected to become a viable alternative to the classical cell disruption and intracellular product recovery.
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