JOURNAL OF BIOTECHNOLOGY
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2025
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IF 3.9
Liang Li,Shanshan Xu,Yanjun Jiang
Ergothioneine (ERG) is a potent antioxidant with applications in nutrition, pharmaceuticals, dermatology, and related fields. However, its large-scale production is constrained by low yields and high costs linked to extraction and chemical synthesis. Microbial fermentation offers a promising alternative. In this study, a truncated NcEgt1–1 from Neurospora crassa and CtEgtB from Chloracidobacterium thermophilum were fused to convert L-histidine and L-cysteine into hercynylcysteine sulfoxide, subsequently catalyzed by MsEgtE from Mycobacterium smegmatis to produce ERG. Initial expression in Escherichia coli yielded 87.02 mg/L of ERG. With the use of a rigid linker-EAAAK, the ERG titer increased to 144 mg/L. Further amino acid modifications in NcEgt1–1 resulted in the mutant strain M3–02, producing 325 mg/L of ERG. Fed-batch fermentation in a 5-L bioreactor achieved an ERG yield of 790 mg/L with a productivity of 9 mg/L/h. Iterative mutations of CtEgtB further increased ERG production to 478 mg/L in shake flasks and 790 mg/L in the bioreactor, with productivity rising to 14.9 mg/L/h. This study presents an engineered strain with significant ERG production potential, suitable for industrial application.
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Environmental Science-Processes & Impacts
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2026
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IF 3.9
Sadiq Naveed,Xinwei Zhou,Dongqiang Zhu
Extracellular reductive dechlorination of chlorinated aliphatic hydrocarbons (CAHs) by non-electroactive bacteria is rarely investigated. In this study, we demonstrated that common bacteria Gram-positive Bacillus subtilis (B. subtilis) and Gram-negative Escherichia coli (E. coli) in aqueous suspensions (1.2 × 108 cells per mL) could dechlorinate a model CAH compound hexachloroethane (HCE, initial 40 µmol L−1) at ratios of 83.7% and 54.1% respectively to pentachloroethane (PCE) and tetrachloroethylene (TCE) after 56 h incubation at pH 7.0 and 30 °C. The majority of the parent compound (HCE) and reaction products (PCE and TCE) present in the extracellular matrix indicated the predominance of extracellular reduction. Removing EPS from bacteria suppressed HCE reduction, while adding extra dissolved EPS slightly enhanced HCE reduction. The enhanced reduction of HCE by low-molecular-weight EPS (<3 kDa) relative to bulk EPS of B. subtilis and its counterpart high-molecular-weight EPS (>3 kDa) indicated that low-molecular-weight EPS were more enriched in active reducing agents. Additionally, dechlorination of HCE by electrochemically reduced glutathione and disodium anthraquinone-2,6-disulfonate or juglone suggested that thiol groups and quinones were involved as reducing agents and electron mediators, respectively. These findings underscore a previously unknown process of extracellular reductive dechlorination of CAHs by common non-electroactive bacteria and the key role played by EPS.
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INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS
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2026
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IF 4.6
Rongrong Dong,Yifei Wang,Lei Song,Jiayin Wang,Chun Yang,Xufeng Ji,Qi Zhou,Hao Wang,Xinhua Guo,Jiancheng Xu
Background Carbapenem-resistant Escherichia coli (CREC) producing New Delhi metallo-beta-lactamase (NDM) poses a substantial threat to global public health. Prompt detection of CREC is essential for effective patient management and to curb the spread of resistance. Objective This study aims to establish a rapid and reliable detection method for NDM-producing CREC using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) in conjunction with machine learning (ML) techniques. Methods Clinical isolates of E. coli were collected from the First Hospital of Jilin University’s clinical laboratory from August 2018 to December 2022. PCR was employed to detect 23 prevalent resistance genes in the isolates. Protein profiles were analyzed by MALDI-TOF MS with a cooperative matrix consisting of (E)-propyl α-cyano-4-hydroxylcinnamylate (CHCA-C3) and α-cyano-4-hydroxycinnamic acid (CHCA). By comparative analysis of nine ML algorithms, the optimal Random Forest (RF) algorithm was identified and used to find the NDM specific ion peaks. Furthermore, the NDM gene was cloned into the standard E. coli strain ATCC 25922 to verify the reliability of these specific peaks. Results A total of 154 E. coli strains were categorized into three groups: 45 CREC strains, 58 extended-spectrum beta-lactamase (ESBL)-producing strains, and 51 non-CREC, non-ESBL strains. PCR amplification identified 12 resistance genes. The established ML model with RF algorithm exhibits excellent discriminative ability, achieving an AUC of 0.993 and an AP of 0.997. Four specific peaks ( m/z 5132, m/z 5209, m/z 6350, and m/z 6371) of NDM were identified using the cooperative matrix. In contrast, the traditional CHCA matrix revealed no specific peaks. Furthermore, the specific peaks at m/z 5132 and m/z 5209 were detected in the MALDI-TOF MS spectra of the recombinant E. coli strain ATCC 25922-PZY01/NDM, which directly correlated with the expression of the NDM gene. Conclusion The integration of MALDI-TOF MS with ML techniques, facilitated by the cooperative matrix approach, has enabled the swift and precise identification of NDM-producing CREC. This advancement significantly enhances the effectiveness of clinical management and the control of hospital-acquired infections.
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JOURNAL OF HAZARDOUS MATERIALS
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2026
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IF 10.6
Xinyi Tang,Yan Wang,Xiumei Chen,Wei Kong,Xue He,Yi Yang
Waterborne pathogenic microorganisms pose serious public health threats by causing gastrointestinal infections and disease outbreaks. However, conventional disinfection technologies suffer from limitations such as high equipment costs, the formation of chlorinated byproducts, and limited scalability. To address these challenges, we developed a heterogeneous oxidative system based on nitrogen-doped carbon materials (N-Cs) for peroxymonosulfate (PMS) activation and efficient microbial inactivation. Using Escherichia coli ( E. coli) as a model pathogen, we demonstrate that the N-Cs /PMS system achieves rapid and effective disinfection via a non-radical, synergistic mechanism. Singlet oxygen ( 1 O 2 ) is identified as the dominant reactive species, initiating a cascade of cellular damage including membrane dysfunction, genomic DNA degradation, and the induction of antioxidant enzymes (e.g., SOD, CAT). In addition, transcriptomic analysis reveals that 1 O 2 generated in the system perturb gene expression related to metabolic regulation and catalytic activity, thereby disrupting bacterial physiology at a systemic level. This work highlights the critical role of 1 O 2 in non-radical disinfection and provides mechanistic insights into PMS-based advanced oxidation processes for microbial control in water treatment applications.
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FOOD RESEARCH INTERNATIONAL
·
2026
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IF 8.8
Liyuan Niu,Huiyi Liu,Xiaoqiao Wu,Ziyue Zhao,Yafei Zhai,Limin Wang,Zhijian Zhang,Qisen Xiang
Freezing induced >80% sublethal injury in Escherichia coli O157:H7 after 21 h. • Injured cells showed membrane damage, ATP depletion, and impaired biofilm formation. • Metabolomics linked freezing injury to pyruvate and fatty acid metabolism. • Resuscitation reactivated nucleotide synthesis, redox balance, and energy production. • Oregano essential oil reduced the sublethal injury ratio in E. coli O157:H7. Freezing stress can induce sublethal injury in foodborne pathogens, allowing injured cells to evade detection and subsequently resuscitate, thereby posing a hidden food safety risk. This study investigated the formation, physiological characteristics, and resuscitation of freezing-induced sublethally injured Escherichia coli O157:H7 at −20 °C and explored the underlying mechanisms using untargeted metabolomics. After 21 h of freezing, the proportion of sublethally injured cells exceeded 80%, accompanied by cell surface collapse, impaired membrane integrity, and depleted intracellular protein and ATP levels. Metabolomic analysis revealed distinct perturbations in pyruvate metabolism, the tricarboxylic acid (TCA) cycle, and fatty acid biosynthesis. Resuscitation in tryptone soy broth at 25 °C for 8 h was accompanied by activation of purine, cysteine and methionine metabolism, glycolysis/gluconeogenesis, and riboflavin metabolism, alongside upregulation of phosphatidylethanolamine indicative of membrane remodeling. Notably, freezing-stressed E. coli cells exhibited significantly enhanced sensitivity to oregano essential oil (OEO), with the sublethal injury ratio decreasing from 79.73% to 22.70% upon OEO treatment at 1/2 × MIC (minimum inhibitory concentration), consistent with the membrane-damage mechanism. These findings provide integrated physiological and metabolomic insights into freezing-induced sublethal injury and support the rational design of membrane-targeting antimicrobials as effective hurdle strategies for frozen food safety. Download: Download high-res image (269KB) Download: Download full-size image
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JOURNAL OF BIOTECHNOLOGY
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2023
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IF 4.1
Fang-Ying Zhu,Qing Yang,Min Cao,Ken Zheng,Xiao-Jian Zhang,Qi Shen,Xue Cai,Zhi-Qiang Liu,Yu-Guo Zheng
d -(−)-Pantolactone (DPL) is a key intermediate for the production of d -(+)-pantothenate (vitamin B5). Deracemization of d , l -pantolactone (D, L -PL) through oxidizing l -(+)-pantolactone (LPL) to ketopantoyl lactone (KPL) and subsequently reducing KPL to DPL is a promising route for synthesizing DPL. Herein, a newly mined l -pantolactone dehydrogenase from Rhodococcus hoagie ( Rho LPLDH) was used for the oxidative dehydrogenation of LPL. To alleviate inclusion bodies formed by membrane-bound Rho LPLDH intracellular expression in E. coli , strategies involving chaperone assistance and decreasing induction temperature were used to achieve Rho LPLDH soluble expression. To enhance its activity, directed evolution and hydrophilicity-based engineering yielded increased catalytic activity and thermostability . 1 M LPL was efficiently converted to KPL by engineering strain CM5 co-expressing Rho LPLDH L254I/V241I/I156L/F224Q/N164K and chaperone. A “two stages in one-pot” method was employed in deracemization of 1 M D, L -PL with 91.2% yield. These results demonstrated that CM5 catalyst exhibits great potential in enzyme cascade deracemization for the production of DPL.
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2023
·Vol. 24
·期 8
·7649
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IF 5.6
Yanjing Liu,Xiyue Li,Yuezhou Liu,Yaping Huang,Fuming Wang,Yongfang Qian,Ying Wang
Due to their high porosity, large specific surface area, and structural similarity with the extracellular matrix (ECM), electrospun nanofiber membranes are often endowed with the antibacterial properties for biomedical applications. The purpose of this study was to synthesize nano-structured Sc2O3-MgO by doping Sc3+, calcining at 600 °C, and then loading it onto the PCL/PVP substrates with electrospinning technology with the aim of developing new efficient antibacterial nanofiber membranes for tissue engineering. A scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS) were used to study the morphology of all formulations and analyze the types and contents of the elements, and an X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR) were used for further analysis. The experimental results showed that the PCL/PVP (SMCV-2.0) nanofibers loaded with 2.0 wt% Sc2O3-MgO were smooth and homogeneous with an average diameter of 252.6 nm; the antibacterial test indicated that a low load concentration of 2.0 wt% Sc2O3-MgO in PCL/PVP (SMCV-2.0) showed a 100% antibacterial rate againstEscherichia coli(E. coli).Keywords:nano-textured;Sc2O3-MgO;antibacterial;electrospinning
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ANALYTICAL CHEMISTRY
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2023
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IF 7.4
Ying Wang,Tong Bu,Yuanyuan Cao,Haiyu Wu,Jia Xi,Qinlin Feng,Chenyu Xuan,Li Wang
Nanozymes have drawn much attention as an enzyme mimetic with low cost and stability in enhancing analytical performance. Herein, a peroxidase-mimicking nanozyme-improved enzyme-linked immunosorbent assay (ELISA) was developed employing the bimetallic PdRu nanozyme to replace the natural enzymes as a catalytic carrier for the sensing of Escherichia coli O157:H7 (E. coli O157:H7). The PdRu nanozyme displayed ultrahigh catalytic activity, possessing a catalytic rate that was 5-fold higher than horseradish peroxidase (HRP). In addition, PdRu exhibited great biological affinity with antibody (affinity constant was about 6.75 × 1012 M) and high stability. All those advantages ensure the successful establishment and the construction of a novel colorimetric biosensor for E. coli O157:H7 detection. PdRu-based ELISA not only achieved an ultrasensitive detection sensitivity (8.7 × 102 CFU/mL) by approximately 288-fold as compared to the traditional HRP-based ELISA and also possessed satisfactory specificity and reproducibility (relative standard deviation (RSD) < 10%). Furthermore, the feasibility of PdRu-ELISA was further evaluated by detecting E. coli O157:H7 in actual samples with satisfactory recoveries, indicating its potential for applications in bioassays and clinical diagnostics.
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PROCESS BIOCHEMISTRY
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2022
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IF 4.885
Zexin Zhao,Jiahao Huang,Long Xu,Changgao Wang,Jun Cai
The efficient methanol-resistant biocatalysts with low costs are always desirable for biodiesel production. Here, an Escherichia coli whole-cell catalyst was constructed with the methanol-resistant MAS1 lipase being expressed intracellularly. Notably, this whole-cell catalyst showed significantly higher methanol-resistance than the purified MAS1 lipase. The whole-cell catalyst with the non-specific MAS1 lipase enabled efficient biodiesel production. Moreover, high-density fermentation was found to reduce the production costs and improve the catalytic activity of the whole-cell catalyst. The wet cells collected by centrifugation were directly used for fatty acid methyl ester (FAME) production from olive oil with one-step addition of methanol. Under the optimal conditions (catalyst loading of only 1.5 wt%, water content of 30 % (v/w), methanol content of 30 % (v/w) and reaction temperature of 29 °C), the maximum yield of 93.56 % was obtained. Furthermore, the whole-cell catalyst showed favorable reusability, with 85 % of the original activities left after a 4-cycle usage. Overall, the whole-cell catalyst reported in the present study would provide great potentials for the enzymatic production of biodiesels.
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Microbial Cell Factories
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2022
·Vol. 21
·期 1
·1-13
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IF 6.352
Zhong Zhi-Hao,Zhang Yu-Qing
Background The immobilized technology for microbial or cells has the advantages of high microbial activity, high microbial density per unit space, good tolerance, strong shock, load resistance, high processing efficiency, and high reuse rate. It is now widely used in environmental remediation, water quality treatment, biodegradation, food industry, chemical analysis, energy development, medicine and pharmaceuticals, and other fields.Results A novel Escherichia coli cell-immobilizing polyvinyl alcohol hydrogel membrane (ECI-PVAHM) was prepared by unidirectional nanopore dehydration (UND) from a 10% polyvinyl alcohol (PVA) aqueous solution containing enhanced green fluorescent protein-labeled E. coli. This bacteria-loaded film has high water stability, flexibility, transparency, and mechanical robustness. Its tensile strength, elongation rate, and swelling rate are in the ranges 0.66–0.90 MPa, 300–390%, and 330–800%, respectively. The effective bacterial load of ECI-PVAHM is 2.375 × 109–1010 CFU/g (dry weight), which does not affect the original crystal structure of the PVAHM. This biofilm has a porous network structure with pore sizes between 0.2 and 1.0 μm, and these cells are embedded in the PVAHM network. When the immobilized cells were continuously cultured for 20 days, and the medium was renewed twice daily, their relative proliferation efficiency after 40 cycles could still be maintained at ~ 91%.Conclusion The above results show that the cell division, proliferation ability, and metabolic activity of immobilized E. coli were not affected by the physical barrier of the porous network structure of the hydrogel. This UND-based ECI-PVAHM has potential applications in molecular biology, biopharmaceutical expression and production, bioreactors, and fuel cells.
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Microbial Biotechnology
·
2023
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IF 5.7
Xinyue Ye,Jian Wang,Pengfei Xu,Xiaoqian Yang,Qixue Shi,Genyan Liu,Zhaoshi Bai,Changlin Zhou,Lingman Ma
Polymyxin resistance is conferred by MCR-1 (mobile colistin resistance 1)-induced lipopolysaccharide (LPS) modification of G − bacteria. However, the peptide MSI-1 exerts potent antimicrobial activity against mcr-1 -carrying bacteria . To further investigate the potential role of MCR-1 in improving bacterial virulence and facilitating immune evasion, and the immunomodulatory effect of peptide MSI-1, we first explored outer membrane vesicle (OMV) alterations of mcr-1 -carrying bacteria in the presence and absence of sub-MIC MSI-1, and host immune activation during bacterial infection and OMV stimulation. Our results demonstrated that LPS remodelling induced by MCR-1 negatively affected OMV formation and protein cargo by E. coli . In addition, MCR-1 diminished LPS-stimulated pyroptosis but facilitated mitochondrial dysfunction, further aggravating apoptosis in macrophages induced by OMVs of E. coli . Similarly, TLR4-mediated NF-κB activation was markedly alleviated once LPS was modified by MCR-1. However, peptide MSI-1 at the sub-MIC level inhibited the expression of MCR-1, further partly rescuing OMV alteration and attenuation of immune responses in the presence of MCR-1 during both infection and OMV stimulation, which can be exploited for anti-infective therapy.
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CHEMISTRY & BIODIVERSITY
·
2022
·Vol. 19
·期 9
·e202200118
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IF 2.745
Bing-Kang Sun,Rui-Yu Wang,Bei Li,Xing Fan,Yuan Zhou,Bing Gu,Yang-Yang Yan
A rapid and accurate analytical method was established to identify CREC and CSEC. Orbitrap-MS was used to detect the polypeptide of CREC and CSEC strains, and MS data were analyzed by pattern recognition analyses such as hierarchical cluster analysis (HCA), principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA). HCA based on the farthest distance method could well distinguish the two types of E. coli , and the cophenetic correlation coefficient of the farthest distance method was 0.901. Comparing the results of PCA, PLS-DA, and OPLS-DA, OPLS-DA exhibited the highest accuracy in predicting the CREC and CSEC strains. A total of 26 compounds were identified, and six of the compounds were the highly significant difference between the two types of strains. MS combined with pattern recognition can achieve a more comprehensive and efficient statistical analysis of complex biological samples. Graphical
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