CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jianhua Qu,Ziwei Li,Siqi Wang,Qiutong Lin,Zhiyu Zhang,Zhihuan Wu,Qi Hu,Zhao Jiang,Yue Tao,Ying Zhang
Herein, magnetic biochar coupled with Acinetobacter lwoffii DNS32 immobilized pellets (DMBC-P) were synthesized through sodium alginate embedding and fixation, which could fast and completely eliminate atrazine from contaminated farmland soil. Characterization results revealed that DMBC-P exhibited a significant abundance of three-dimensional network porous structures, thereby enhancing the stability and specific surface area of DMBC-P. The application of 0.5 % DMBC-P could completely remove 22 mg/kg atrazine from soil within 4 d under the condition of moisture content of 60 % and soil pH of 7.4. After 5 d of remediation, DMBC-P could be easily extracted from the soil by magnetic separation and still had 100 % removal efficiency for atrazine after 3 rounds of recycling. Moreover, DMBC-P effectively alleviated the oxidative damage of atrazine to soybean seedlings through significantly decreasing the activities of various plants antioxidant enzymes by 27 % to 79 %. Meanwhile, analysis of 16S rRNA revealed a significant increase in the relative abundance of functional microflora such as Acidobacteriota and Chloroflexi at the phylum level, which promoted the growth of soybean seedlings. Additionally, pore filling, hydrogen bonding, and π-π stacking were identified as the primary mechanisms responsible for atrazine adsorption onto DMBC-P. Subsequently, the degrading bacteria DNS32 immobilized on DMBC-P was employed to catalyze the decomposition of atrazine into non-toxic cyanuric acid based on LC-MS. Overall, this study provided a reasonable design of magnetic carbon-based bacterial pellet for atrazine-contaminated soil remediation, which could efficiently remove atrazine and be effectively recycled after remediation.
研究领域:
环境科学
·
土壤微生物学
·
生物修复
·
分析化学
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2026
·Vol. 74
·期 28
·22149-22158
·
IF 6.7
Sun Ze-Rui,Xia Yu-Xin,Li Yi-Ran,Liu Li,Voglmeir Josef
The deacetylation of N -acetylglucosamine
(GlcNAc)
to glucosamine (GlcN) is a key step in enzymatic chitin valorization.
We identified a novel GlcNAc deacetylase (AbNGD) from Acinetobacter baumannii with high substrate specificity
and catalytic activity but poor thermal stability (half-life of 5.5
h at 37 ° C). Using the FireProt platform, we generated a combinatorial
mutant, AbNGD-M3 (T93P–C153T-A244M). Its optimal temperature
increased to 37 ° C, and its half-life reached 28.1 h (5.1-fold
improvement), while retaining 97% of wild-type catalytic efficiency
( k cat / K m =
3.4 mM –1 ·s –1 ). Site-directed
mutagenesis confirmed Asp54 and His160 as key catalytic residues.
Molecular dynamics simulations revealed that T93P reduces backbone
flexibility, C153T enhances β-sheet rigidity via hydrogen bonding,
and A244M improves hydrophobic packing by filling a core cavity. These
distal mutations collectively balance stability and activity. Substrate
channel analysis identified a likely transport pathway centered on
T1. This study expands the deacetylase repertoire and provides a framework
for engineering stable industrial enzymes.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Guoxiang Yang,Haibo Yin,Wenhua Liu,Yuping Yang,Quan Zou,Liulin Luo,Huiping Li,Yuning Huo,Hexing Li
The hybrid Ag/TiO 2 -N photocatalyst was prepared via a supercritical solvothermal process in ethanol fluid. The simultaneous achievement of reduction of Ag + ions and N-doping in silver-ammonia complex solution led to the uniform distribution of Ag nanoparticles stably combined with the surface of TiO 2 -N substrate. As a result, the visible-light photocatalytic inactivation of Acinetobacter baumannii was facilitated via the enhanced visible light harvesting and the high separation efficiency of photo-induced charge carriers. By means of the main active species of O 2 − radical, the synergistic effect of Ag nanoparticles and TiO 2 -N could induce the structure change of bacteria with the leakage of K + ions as well as the mineralization of cell membrane with the elimination of self-repair function, leading to the final cell death. In comparison, the bactericidal activity of Ag nanoparticles and TiO 2 -N under UV light irradiation was due to the intrinsic efficiency and the high light harvesting, respectively. The photothermal effect of Ag nanoparticles in the near-IR light region could be possibly remained by TiO 2 -N substrate to achieve the antibacterial activity. Furthermore, Ag/TiO 2 -N photocatalyst played great bactericidal effect for kinds of bacteria, implying the applicable future to the medical disinfection.
研究领域:
材料科学
·
微生物学
·
光催化技术
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高影响因子
Frontiers in Cellular and Infection Microbiology
·
2021
·
IF 5.293
Li Xiaobo,Song Yanqing,Wang Lina,Kang Guangbo,Wang Ping,Yin Huabing,Huang He
Multidrug-resistant (MDR) Acinetobacter baumannii strains can cause severe infections in intensive care units, and are rapidly developing resistance to the last-resort of existing antibiotics, posing a major global threat to health care system. Berberine hydrochloride (BBH), a kind of isoquinoline alkaloids extracted from Berberis and other plants, has been widely used as an antibacterial medicine for its reliable therapeutic efficiency. The in vitro synergistic effects of BBH with antibiotics against MDR A. baumannii were determined. BBH alone had weak antimicrobial activity (e.g., MIC≥256 mg/L) against MDR A. baumannii. However, it dramatically increased the susceptibility of MDR strains against antibiotics with FICI values <0.5, even reversed their resistance to antibiotics (e.g., tigecycline, sulbactam, meropenem and ciprofloxacin). In vivo study has suggested BBH with sulbactam had stronger antimicrobial efficiency than monotherapy in a neutropenic murine thigh infection model. The antibiotic-sensitizing mechanism of action of BBH was evaluated as well. BBH boosted adeB gene expression and bound to the AdeB transporter protein, resulting in low uptake of BBH, which may contribute to less extrusion of antibiotics by the AdeABC pump. Knockout of the adeB gene increased uptake of BBH and diminished the antibiotic sensitization and synergistic effects between antibiotics and BBH in MDR strains. Together, BBH effectively re-sensitizes this MDR pathogen to a range of antibiotics that have become barely effective due to antibiotic resistance, which indicates BBH may be a promising therapeutic adjuvant candidate to combat MDR A. baumannii.
研究领域:
微生物学
·
药理学
·
传染病学
·
分子生物学
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高影响因子
Microbiology Spectrum
·
2022
·Vol. 10
·期 4
·
IF 9.043
Hongfa Lv,Yonglin Zhou,Baichen Liu,Jian Guan,Peng Zhang,Xuming Deng,Dan Li,Jianfeng Wang
Acinetobacter baumannii, one of the most successful bacteria causing severe nosocomial infection, was identified as a top-priority pathogen by the WHO. Thus, genetic manipulations to clarify the potential targets for fighting A. baumannii resistance and virulence are vital. Polyphosphate (polyP) kinase (PPK) is conserved in nearly all bacteria and is responsible for polyP formation, which is associated with bacterial pathogenicity and antibiotic resistance. In this study, ppk1-deficient (Δppk1::Apr), ppk1-complemented (Δppk1::Apr/PJL02-ppk1), and wild-type strains of A. baumannii ATCC 17978 were used to determine the influence of PPK1 on A. baumannii virulence and persistence mainly by polyP quantification, surface motility, biofilm formation, and bacterial persistence assays. Our work found that PPK1 is indispensable for polyP formation in vivo and that the motility of the PPK1-deficient strain was significantly impaired due to the lack of a pilus-like structure typically present compared with the complemented and wild-type strains. The deficiency of PPK1 also inhibited the biofilm formation of A. baumannii and decreased bacterial persistence under stimuli of high-concentration ampicillin (Amp) treatment, H2O2 stress, heat shock, and starvation stress. Furthermore, ppk1-deficient bacterium-infected mice showed a significantly reduced bacterial load and a decreased inflammatory response. However, complementation with PPK1 effectively rescued the impaired virulence and persistence of ppk1-deficient A. baumannii. In addition, metabonomic analysis revealed that PPK1 was associated with glycerophospholipid metabolism and fatty acid biosynthesis. Taken together, our results suggest that targeting PPK1 to control A. baumannii pathogenicity and persistence is a feasible strategy to fight this pathogen.IMPORTANCE A. baumannii was identified as a top-priority pathogen by the WHO due to its antibiotic resistance. Meanwhile, the pathogenicity of A. baumannii mediated by several vital virulence factors also cannot be ignored. Here, the role of PPK1 in A. baumannii was also explored. We found that the motility ability and biofilm formation of a PPK1-deficient strain were significantly impaired. Furthermore, PPK1 was essential for its persistence maintenance to resist stimuli of high-concentration Amp treatment, H2O2 stress, heat shock, and starvation stress. Metabonomic analysis revealed that PPK1 was associated with glycerophospholipid metabolism and fatty acid biosynthesis. In addition, ppk1-deficient bacterium-infected mice showed significantly reduced bacterial loads and a decreased inflammatory responses in vivo. Together, our results suggest that PPK1 is vital for A. baumannii pathogenicity and persistence.
研究领域:
微生物学
·
感染病学
·
药理学
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高影响因子
MOLECULES
·
2022
·Vol. 27
·期 19
·6670
·
IF 4.927
Linshu Jiao,Huibing Chi,Bingjie Xia,Zhaoxin Lu,Xiaomei Bie,Haizhen Zhao,Fengxia Lu,Meirong Chen
To extend the application range of L-asparaginase in food pre-processing, the thermostability improvement of the enzyme is essential. Herein, two non-conserved cysteine residues with easily oxidized free sulfhydryl groups, Cys8 and Cys283, ofAcinetobacter soliL-asparaginase (AsA) were screened out via consensus design. After saturation mutagenesis and combinatorial mutation, the mutant C8Y/C283Q with highly improved thermostability was obtained with a half-life of 361.6 min at 40 °C, an over 34-fold increase compared with that of the wild-type. Its melting temperature (Tm) value reaches 62.3 °C, which is 7.1 °C higher than that of the wild-type. Molecular dynamics simulation and structure analysis revealed the formation of new hydrogen bonds of Gln283 and the aromatic interaction of Tyr8 formed with adjacent residues, resulting in enhanced thermostability. The improvement in the thermostability of L-asparaginase could efficiently enhance its effect on acrylamide inhibition; the contents of acrylamide in potato chips were efficiently reduced by 86.50% after a mutant C8Y/C283Q treatment, which was significantly higher than the 59.05% reduction after the AsA wild-type treatment. In addition, the investigation of the mechanism behind the enhanced thermostability of AsA could further direct the modification of L-asparaginases for expanding their clinical and industrial applications.Keywords:L-asparaginase;Acinetobacter soli;thermostability;consensus design;cysteine substitution;acrylamide inhibition
研究领域:
酶学
·
生物技术
·
食品科学
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高影响因子
Frontiers in Bioengineering and Biotechnology
·
2023
·
IF 5.7
Gui Shumin,Li Xisheng,Feng Mingming,Liu Hui,Huang Liwenhui,Niu Xinqing
In recent years, the treatment of Acinetobacter baumannii infections has become a pressing clinical challenge due to its increasing incidence and its serious pathogenic risk. The research and development of new antibacterial agents for A. baumannii have attracted the attention of the scientific community. Therefore, we have constructed a new pH-responsive antibacterial nano-delivery system (Imi@ZIF-8) for the antibacterial treatment of A. baumannii. Due to its pH-sensitive characteristics, the nano-delivery system offers an improved release of the loaded imipenem antibiotic at the acidic infection site. Based on the high loading capacity and positive charge of the modified ZIF-8 nanoparticles, they are excellent carriers and are suitable for imipenem loading. The Imi@ZIF-8 nanosystem features synergistic antibacterial effects, combining ZIF-8 and imipenem to eliminate A. baumannii through different antibacterial mechanisms. When the loaded imipenem concentration reaches 20 µg/mL, Imi@ZIF-8 is highly effective against A. baumannii in vitro. Imi@ZIF-8 not only inhibits the biofilm formation of A. baumannii but also has a potent killing effect. Furthermore, in mice with celiac disease, the Imi@ZIF-8 nanosystem demonstrates excellent therapeutic efficacy against A. baumannii at imipenem concentrations of 10 mg/kg, and it can inhibit inflammatory reaction and local leukocyte infiltration. Due to its biocompatibility and biosafety, this nano-delivery system is a promising therapeutic strategy in the clinical treatment of A. baumannii infections, providing a new direction for the treatment of antibacterial infections.
研究领域:
药学
·
纳米技术
·
微生物学
·
传染病学
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Virulence
·
2026
·
IF 6.8
Rong Yu,Mona Mohamed Al-Shamiri,Sirui Zhang,Pu Li,Cheng Lei,Haiping Liu,Lirui Xue,Kai Luo,Bei Han,Meng Xun,E Yang,Lei Han
Biofilm formation is critical for the persistence of Acinetobacter baumannii, yet its directional correlation with antimicrobial resistance remains paradoxical. Here, we confirmed our prior finding that drug-sensitive and multidrug-resistant (MDR) strains employ distinct, temporally regulated biofilm developmental programs: susceptible strains excel at rapid biomass accumulation but undergo early collapse, while MDR strains delay biofilm initiation and optimize for the maintenance and reinforcement of mature biofilms. Transcriptomic profiling identified the organic hydroperoxide resistance protein (Ohr) as a crucial contributor mediating this strain-specific biofilm divergence, with its deletion resulting in severe biofilm defects. Metabolomics analyses further revealed that Ohr maintains biofilm integrity through dual mechanisms: by modulating redox homeostasis and regulating extracellular polymeric substance (EPS) production through control of AdeAB and AdeFG efflux pumps. Moreover, we identified indole-3-lactic acid as a potent biofilm inhibitor. Our findings suggest Ohr as a linchpin in A. baumannii biofilm development, elucidate the basis of temporal phenotypic divergence, and unveil promising therapeutic targets against biofilm-associated infections.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2026
·
IF 6.7
Kou Boxiang,Yue Yufei,Wang Lei,Ma Dan,Sun Zhongsen,Liu Yuwei,Zhang Zilian,Dong Sijun
The accumulation
of acetaminophen (APAP) in agricultural soils
and water systems poses risks to ecosystems and public health. This
study characterizes Acinetobacter sp. DL27, an APAP-degrading
strain with broad temperature and pH adaptability, demonstrating its
bioremediation potential in soil and wastewater. Through high-resolution
mass spectrometry, we identified three novel metabolic intermediates,
thereby refining the bacterial APAP degradation pathway. Multiomics
analysis elucidated metabolic coordination and stress-tolerance mechanisms,
leading to the identification of a novel amidase (AdA). Recombinant
AdA exhibited activity over 10–60 ° C and pH 4.0–10.0,
with a K m of 8.96 ±
1.03 μM and a k cat / K m of 9.04 μM –1 s –1 , indicating higher catalytic efficiency than
previously reported APAP amidases. Molecular dynamics simulations
and site-directed mutagenesis confirmed that a Ser161–Ser185–Lys82
triad constitutes the catalytic center driving amide cleavage. These
findings provide mechanistic insights into bacterial APAP biodegradation
and highlight the practical application potential of strain DL27 and
AdA.
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JOURNAL OF ANTIBIOTICS
·
2025
·
IF 2.7
Jiang Hanxiang,Qi Jiangfeng,Wang Jiwen,Chen Jiaqin,Feng Dong,Yang Junbiao,Liu Xinna,Liu Mengqun,Zhou Xvzhe,An Zhilong,Lu Yuanyuan,Ge Chun,Wang Ying
Acetobacter baumannii poses escalating clinical challenges due to its exceptional adaptability, demanding innovative antimicrobial strategies. This study pioneers an investigation into the antibacterial efficacy and molecular mechanism of Terramide A, a hydroxamate siderophore isolated from Aspergillus terreus, against notorious A. baumannii . Employing a multidisciplinary approach integrating phenotypic characterization with mechanistic interrogation, we demonstrate that Terramide A exerts significant inhibitory effects against A. baumannii and P. aeruginosa , pathogens critically dependent on siderophore-mediated iron acquisition for survival and virulence. Structural characterization underlines the hydroxamate moieties of Terramide A presumably supports its hypothesized role as a fungal siderophore, involving competitive iron sequestration and bacterial homeostasis. Subsequently, multi-omics investigation of susceptible strain AB19606 delineated a metabolic collapse cascade due to iron acquisition competition: (1) impairment of central metabolism and energy production through oxidative phosphorylation (OXPHO) inhibitions; (2) compromised stress adaptation and bacterial flexibility; (3) compensatory overactivation of siderophores biosynthesis and transportation, depleting metabolic intermediates and exacerbating stress; (4) coordinated suppression of virulence determinants, such as secretory systems and biofilm formation. These molecular derangements translated into phenotypic deficits, including quorum sensing, diminished autoinducer peptides production, and morphological/functional abnormalities. In vivo evaluation in a rat skin wound infection model further demonstrated that Terramide A promotes wound healing and mitigates inflammation, supporting its antibacterial efficacy. These findings establish Terramide A as a promising antibacterial agent and provide critical insights into iron-competitive antimicrobial strategies to exploit micro-nutrient deprivation and metabolic dysfunction. However, further research is needed to optimize the siderophore-based scaffold, clarify its mechanisms, and assess therapeutic potential.
研究领域:
微生物学
·
药理学
·
感染病学
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PubMed
高影响因子
BMC MICROBIOLOGY
·
2026
·
IF 5.4
Hao Danrui,Huang Yuhang,Zhao Tianzhu,Wang Runyu,Jiang Wei,Yuan Xiangting,Wang Xinrong,Chu Yiwen,Zhao Kelei,Huang Ting,Wang Zhenxing
Background Acinetobacter baumannii is a notorious clinical pathogen that predominantly causes nosocomial infections. The multidrug resistant Acinetobacter baumannii clinical isolates are becoming more prevalent on a global scale. In this study, we aimed to determine the potential synergistic antibacterial activity of contezolid in combination with polymyxin B nonapeptide (PBNP) against various A. baumannii strains. Results Contezolid, a commonly-used agents targeting Gram-positive bacteria, in combination with PBNP (CP) was used to explore the potential synergistic antibacterial activity against A. baumannii in vitro and Caenorhabditis elegans models. We found that CP treatment exhibited a strong synergistic effect on A. baumannii or multidrug resistant A. baumannii . CP also inhibited the biofilm formation and alter morphology of A. baumannii compared to the control group. Moreover, the residual bacteria were significantly decreased in the CP-treated murine alveolar macrophages (MH-S). Importantly, CP treatment improved the survival of C. elegans compared to the control or monotherapy group. Conclusions This strategy improved antibacterial activity spectrum of agents targeting Gram-positive bacteria like contezolid. Nevertheless, CP combination therapy requires further validation in mammalian infection models.
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Infection and Drug Resistance
·
2018
·
IF 3.443
Zhihui Jiang,Xianxia He,Jian Li
Purpose: The main objective of our meta-analysis was to examine the in vitro synergistic effect of meropenem-based combination therapies against Acinetobacter baumannii through a systematic review of the existing literature.Methods: An extensive search was performed with no restrictions on date of publication, language, and publication type. Our study evaluated the main conclusions drawn from various studies describing the synergistic activity of combination therapies in vitro.Results: In this review, 56 published studies were included. Our report included data on 20 types of antibiotics combined with meropenem in 1,228 Acinetobacter baumannii isolates. In time-kill studies, meropenem combined with polymyxin B and rifampicin showed synergy rates of 98.3% (95% CI, 83.7%–100.0%) and 89.4% (95% CI, 57.2%–100.0%), respectively, for Acinetobacter baumannii, modest synergy rates were found for meropenem combined with several antibiotics such as colistin and sulbactam, and no synergy effect was displayed in the combination of meropenem and ciprofloxacin, whereas in checkerboard method, the synergy rates of polymyxin B and rifampicin were 37.0% (95% CI, 0.00%–100.0%) and 56.3% (95% CI, 8.7%–97.8%), respectively.Conclusion: We found that time-kill studies generally identified the greatest synergy, while checkerboard and Etest methods yielded relatively poor synergy rates. Further well-designed in vivo studies should be carried out to confirm these findings.
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