MICROBIAL PATHOGENESIS
·
2023
·
IF 3.8
Navni Rohatgi,Dhanraj Ganapathy,Palanivel Sathishkumar
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that form biofilms in chronic wounds and is difficult to treat with standard treatment methods. In the present study, flavonoid quercetin-mediated CuONPs (Que-CuONPs) were successfully synthesized and incorporated in the electrospun polycaprolactone (Que-CuONPs-PCL) nanofibrous membrane to eradicate the burn wound infection causing P. aeruginosa biofilm. The fabricated scaffold Que-CuONPs-PCL was characterized using HR-SEM, EDX, XRD, and FTIR. The synthesized Que-CuONPs appeared as spherical in shape with the average size of 36 nm. The crystallite size of the synthesized CuONPs was calculated as 23 nm. Antibacterial activity results shows that the ZOI and MIC of Que-CuONPs against P. aeruginosa was found to be 20 mm and 5 μg/mL, respectively. Antibiofilm assay results indicate the pre-formed P. aeruginosa biofilm was completely eradicated by Que-CuONPs at 8-MIC. The Que-CuONPs-PCL nanofibrous scaffolds exhibits less cytotoxic effects on mouse fibroblast (L929) cells. Finally, this study highlights the fabricated Que-CuONPs-PCL nanofibrous scaffolds exhibits an excellent antibiofilm effect against P. aeruginosa biofilm with a great biocompatibility .
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2023
·
IF 6.1
Wanqing Zhang,Haixian Liu,Yuxuan Xiao,Jie Ying,Hongwei Liu
Oxygen evolution reaction (OER) has gained increasing attention among researchers due to its significance in energy conversion. However, the sluggish kinetics of the OER present notable challenges. In this work, we present an energy-efficient, cost-effective, widely applicable, and scaled-up biological preparation method to prepare OER catalytic materials with high activity and stability based on bacteria and inexpensive Ni-Fe foam under mild conditions. Anaerobic sulfate-reducing bacterium Desulfovibrio caledoniensis and aerobic Pseudomonas stutzeri are the typical microorganisms and the OER performance of their products is not clear. Electrochemical measurements show that the catalyst prepared via D. caledoniensis exhibits a low overpotential of only 247 mV to achieve 10 mA cm −2 and a low Tafel slope of 46 mV dec -1 , while the catalyst prepared via P. stutzeri has an overpotential and Tafel slope of 259 mV and 71 mV dec -1 , respectively. Therefore, these catalysts exhibit excellent catalytic activities. Furthermore, they have a good stability of more than 40 h at 10 mA cm −2 which is far superior to that of the majority of reported NiFe-based OER catalysts. This work shows new insights into the preparation and development of high-performance OER catalysts in mild conditions.
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Yating Jia,Fan Hu,Yuancai Lv,Yuancai Chen,Yongyou Hu
Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants and challenges for water treatment due to their persistence and toxicity. In this study, the reduction of 2′2′4′4′-tetrabromodiphenyl ether (BDE-47) was investigated in a nano-bio-integrated system. Results showed that the introducing of P. putida could markedly accelerate the demineralization of BDE-47 in nZVI/Pd- P.p system; the continuous generation of acidic metaboliates by P. putida could decrease pH, which could alleviate the surface passivation to some extent, resulting in the releasing of Fe 2+ and high generation of H 2 O 2 , the shift in reactive oxygen species from Fe(IV) to •OH. The BDE-47 was firstly debrominated to the DE by the highly reductive [Pd·2H] generated by nZVI/Pd, then oxidized to bromophenol and phenol, catechol as well as hydroquinone via the P. putida strain and the Fenton-like system. The toxicity assays confirmed the combined system could avert generation of nocuous intermediates, and could be an alternative strategy for complete remediation of recalcitrant POPs.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-11
·
IF 4.259
Huang Haiying,Tao Xuanyu,Jiang Yiming,Khan Aman,Wu Qi,Yu Xuan,Wu Dan,Chen Yong,Ling Zhenmin,Liu Pu,Li Xiangkai
Soil contamination by PAH and heavy metals is a growing problem. Here, we showed that a new isolate, Pseudomonas brassicacearum strain LZ-4, can simultaneously degrade 98% of 6 mM naphthalene and reduce 92.4% of 500 μM hexavalent chromium [Cr (VI)] within 68 h. A draft genome sequence of strain LZ-4 (6,219,082 bp) revealed all the genes in the naphthalene catabolic pathway and some known Cr (VI) reductases. Interestingly, genes encoding naphthalene pathway components were upregulated in the presence of Cr (VI), and Cr (VI) reduction was elevated in the presence of naphthalene. We cloned and expressed these naphthalene catabolic genes and tested for Cr (VI) reduction, and found that NahG reduced 79% of 100 μM Cr (VI) in 5 minutes. Additionally, an nahG deletion mutant lost 52% of its Cr (VI) reduction ability compared to that of the wild-type strain. As nahG encodes a salicylate hydroxylase with flavin adenine dinucleotide (FAD) as a cofactor for electron transfer, Cr (VI) could obtain electrons from NADH through NahG-associated FAD. To the best of our knowledge, this is the first report of a protein involved in a PAH-degradation pathway that can reduce heavy metals, which provides new insights into heavy metal-PAH contamination remediation.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
·
2024
·
IF 5
Congnan Cen,Xinxuan Wang,Huan Li,Jian Chen,Yanbo Wang
Pseudomonas fluorescens is a spoilage bacterium in food that has the ability to maintain growth and reproduction in high-salt environments. It acts as a defence mechanism through the exclusion of ions and the formation of biofilms. Hence, disrupting this defence mechanism may be a good way to control food spoilage. In this study, a specific flavonoid small molecule baicalin was found, which was able to dismantle the defence mechanism of the bacteria at a lower concentration (400 μM) of treatment. In synergy with salt, baicalin showed a significant inhibitory effect on the growth, c -di-gmp synthetics and biofilm formation of Pseudomonas fluorescens Pf08. Through transcriptomics , we also found that baicalein interfered with bacterial transport and polysaccharide production functions. Through molecular docking and QPCR , we found that baicalin is able to binding with the RpoS protein through hydrogen bonding and thus interfere with its function.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-15
·
IF 15.7
You Yanling,Yu Xu,Jiang Junjie,Chen Zhixin,Zhu Ya-Xuan,Chen Yihan,Lin Han,Shi Jianlin
Personalized synergistic antibacterial agents against diverse bacterial strains are receiving increasing attention in combating antimicrobial resistance. However, the current research has been struggling to strike a balance between strain specificity and broad-spectrum bactericidal activity. Here, we propose a bacterial cell wall-specific antibacterial strategy based on an in situ engineered nanocomposite consisting of carbon substrate and decorated TiO x dots, termed TiO x @C. The fiber-like carbon substrate of TiO x @C is able to penetrate the bacterial membrane of Pseudomonas aeruginosa ( P. aeruginosa ), but not that of Staphylococcus aureus ( S. aureu s) due to its thicker bacterial wall, thus achieving bacterial wall specificity. Furthermore, a series of experiments demonstrate the specific electro-mechanical co-sterilization effect of TiO x @C. On the one hand, TiO x @C can disrupt the electron transport chain and block the energy supply of S. aureus . On the other hand, TiO x @C capable of destroying the membrane structure of P. aeruginosa could cause severe mechanical damage to P. aeruginosa as well as inducing oxidative stress and protein leakage. In vivo experiments demonstrate the efficacy of TiO x @C in eliminating 97% of bacteria in wounds and promoting wound healing in wound-infected female mice. Overall, such a bacterial cell wall-specific nanomedicine presents a promising strategy for non-antibiotic treatments for bacterial diseases.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
·
2024
·
IF 3.9
Yucheng Wang,Xue Li,Hongtong Chen,Xinyi Yang,Lei Guo,Rui Ju,Tianhong Dai,Guoqing Li
Pseudomonas aeruginosa , a notable pathogen frequently associated with hospital-acquired infections, displays diverse intrinsic and acquired antibiotic resistance mechanisms, posing a significant challenge in infection management. Antimicrobial blue light (aBL) has been demonstrated as a potential alternative for treating P. aeruginosa infections. In this study, we investigated the impact of blue light wavelength, bacterial growth stage, and growth medium composition on the efficacy of aBL. First, we compared the efficacy of light wavelengths 405 nm, 415 nm, and 470 nm in killing three multidrug resistant clinical strains of P. aeruginosa . The findings indicated considerably higher antibacterial efficacy for 405 nm and 415 nm wavelength compared to 470 nm. We then evaluated the impact of the bacterial growth stage on the efficacy of 405 nm light in killing P. aeruginosa using a reference strain PAO1 in exponential, transitional, or stationary phase. We found that bacteria in the exponential phase were the most susceptible to aBL, followed by the transitional phase, while those in the stationary phase exhibited the highest tolerance. Additionally, we quantified the production of reactive oxygen species (ROS) in bacteria using the 2′,7′-dichlorofluorescein diacetate (DCFH-DA) probe and flow cytometry, and observed a positive correlation between aBL efficacy and ROS production. Finally, we determined the influence of growth medium on aBL efficacy. PAO1 was cultivated in brain heart infusion (BHI), Luria-Bertani (LB) broth or Casamino acids (CAA) medium, before being irradiated with aBL at 405 nm. The CAA-grown bacteria exhibited the highest sensitivity to aBL, followed by those grown in LB broth, and the BHI-grown bacteria demonstrated the lowest sensitivity. By incorporating FeCl 3 , MnCl 2 , ZnCl 2 , or the iron chelator 2,2′-bipyridine (BIP) into specific media, we discovered that aBL efficacy was affected by the iron levels in culture media.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Zihao Huang,Yingdan Piao,Xiemuxinuer Abuduwupuer,Simeng Ding,Tian Chen,Song Jiang,Yiqi Ding,Zheng Guo,Renjun Gao
Catecholic compounds caused consequential environmental pollution and posed severe threats to human health. Despite microbial biodegradation of phenolic aromatics providing a naturally evolved solution, the poor degradation viability of natural microbes decisively restricts their practical application for bioremediation. Herein, we demonstrated an effective strategy that the biodegradation capability of a natural Pseudomonas strain P. putida (Pp18) towards catecholic pollutants can be significantly enhanced in the folds of 2–12 with extended catecholic scopes. Based on the analysis of two-mode metabolic pathways of catecholics, the strategy started from screening of Pseudomonas strains, followed by constructing and improving Extradiol dioxygenase (EDO)-hydrolysis pathway with home-discovered EDO Tcu3516 as a starting point. Together with 2-hydroxy-6-oxohexa-2,4-dienoate hydrolase (HIU89), EDO Tcu3516 were co-expressed and further integrated with endogenous enzymes to improve the metabolic efficiency of EDO-hydrolysis mode. The dual-expression strain Tcu-HIU-pV-Pp18 demonstrated greatly enhanced degradation viability towards mono-and di- hydric phenols, e.g. o -cresol and 3-methylcatechol, in a fold of 8 compared to the parent strain. Furthermore, 5 EDO mutants from engineering of Tcu3516 were tested for construction, transformation and co-expression in Pp18, which the strain of NA (mutant V212N/D285A of Tcu3516)-HIU-pV-Pp18 demonstrated further improved biodegrading variability, excellent robustness and resilience to withstand high-concentration toxic catecholic pollutants.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Huoyong Jiang,Xuexiu Yu,Jingjing Guo,Guangdong Shang,Yijun Dai
The amides 4-trifluoromethylnicotinamide, acrylamide, and benzamide are widely used in agriculture and industry, posing hazards to the environment and animals. Immobilized bacteria are preferred in wastewater treatment, but degradation of these amides by immobilized engineered bacteria has not been explored. Here, engineered Pseudomonas putida KT2440 pLSJ15-amiA was constructed by introducing a new amidase gene expression vector into environmentally safe P. putida KT2440. P. putida KT2440 pLSJ15-amiA had high amidase activity, even at 80 °C. P. putida KT2440 pLSJ15-amiA immobilized with calcium alginate exhibited a greater environmental tolerance than free cells. The amides were rapidly degraded by the immobilized cells, but the activity was inhibited by high concentrations of substrates. The substrate inhibition model revealed that the optimum initial concentrations of 4-trifluoromethylnicotinamide, acrylamide, and benzamide for degradation by immobilized cells were 197.65, 350.76, and 249.40 μmol/L, respectively. This study develops a novel and excellent immobilized biocatalyst for remediation of wastewater containing hazardous amides.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 9
·971
·
IF 4.501
Zewang Guo,Denghui Chen,Qi Xiong,Miao Liang,Pengfei Li,Zehui Gong,Junzhi Qiu,Liaoyuan Zhang
Leucine dehydrogenase (LeuDH) has emerged as the most promising biocatalyst for L-tert-leucine (L-Tle) production via asymmetric reduction in trimethylpyruvate (TMP). In this study, a new LeuDH namedPbLeuDH from marinePseudomonas balearicawas heterologously over-expressed inEscherichia coli, followed by purification and characterization.PbLeuDH possessed a broad substrate scope, displaying activities toward numerous L-amino acids andα-keto acids. Notably, compared with those reported LeuDHs,PbLeuDH exhibited excellent catalytic efficiency for TMP with aKmvalue of 4.92 mM and akcat/Kmvalue of 24.49 s−1mM−1. Subsequently, L-Tle efficient production was implemented from TMP by whole-cell biocatalysis using recombinantE. colias a catalyst, which co-expressedPbLeuDH and glucose dehydrogenase (GDH). Ultimately, using a fed-batch feeding strategy, 273 mM (35.8 g L−1) L-Tle was achieved with a 96.1% yield and 2.39 g L−1h−1productivity. In summary, our research provides a competitive biocatalyst for L-Tle green biosynthesis and lays a solid foundation for the realization of large-scale L-Tle industrial production.Keywords:leucine dehydrogenase;L-tert-leucine;trimethylpyruvate;reductive amination;whole-cell biocatalysis
✓ 已验证
DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2016
·Vol. 82
·期 2
·
IF 3.823
Hong-Jun Chao,Yan-Fei Chen,Ti Fang,Ying Xu,Wei E. Huang,Ning-Yi Zhou
In addition to growing on p-cresol, Pseudomonas putida NCIMB 9866 is the only reported strain capable of aerobically growing on 2,4-xylenol, which is listed as a priority pollutant by the U.S. Environmental Protection Agency. Several enzymes involved in the oxidation of the para-methyl group, as well as the corresponding genes, have previously been reported. The enzyme catalyzing oxidation of the catabolic intermediate 4-hydroxyisophthalate to the ring cleavage substrate protocatechuate was also purified from strain NCIMB 9866, but its genetic determinant is still unavailable. In this study, the gene hipH, encoding 4-hydroxyisophthalate hydroxylase, from strain NCIMB 9866 was cloned by transposon mutagenesis. Purified recombinant HipH-His6 was found to be a dimer protein with a molecular mass of approximately 110 kDa. HipH-His6 catalyzed the hydroxylation of 4-hydroxyisophthalate to protocatechuate with a specific activity of 1.54 U mg−1 and showed apparent Km values of 11.40 ± 3.05 μM for 4-hydroxyisophthalate with NADPH and 11.23 ± 2.43 μM with NADH and similar Km values for NADPH and NADH (64.31 ± 13.16 and 72.76 ± 12.06 μM, respectively). The identity of protocatechuate generated from 4-hydroxyisophthalate hydroxylation by HipH-His6 has also been confirmed by high-performance liquid chromatography and mass spectrometry. Gene transcriptional analysis, gene knockout, and complementation indicated that hipH is essential for 2,4-xylenol catabolism but not for p-cresol catabolism in this strain. This fills a gap in our understanding of the gene that encodes a critical step in 2,4-xylenol catabolism and also provides another example of biochemical and genetic diversity of microbial catabolism of structurally similar compounds.
✓ 已验证
DOI
PubMed
高影响因子
MICROBIOLOGICAL RESEARCH
·
2016
·
IF 2.723
Waseem Raza,Ning Ling,Dongyang Liu,Zhong Wei,Qiwei Huang,Qirong Shen
The volatile organic compounds (VOCs) produced by soil microbes have a significant role in the control of plant diseases and plant growth promotion. In this study, we examined the effect of VOCs produced by Pseudomonas fluorescens strain WR-1 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum . The VOCs produced by P. fluorescens WR-1 exhibited concentration dependent bacteriostatic effect on the growth of R. solanacearum on agar medium and in infested soil. The VOCs of P. fluorescens WR-1 also significantly inhibited the virulence traits of R. solanacearum . The proteomics analysis showed that the VOCs of P. fluorescens WR-1 downregulated cellular proteins of R. solanacearum related to the antioxidant activity, virulence, inclusion body proteins, carbohydrate and amino acid synthesis and metabolism, protein folding and translation, methylation and energy transfer, while the proteins involved in the ABC transporter system, detoxification of aldehydes and ketones, protein folding and translation were upregulated. This study revealed the significance of VOCs of P. fluorescens WR-1 to control the tomato wilt pathogen R. solanacearum . Investigation of the modes of action of biocontrol agents is important to better comprehend the interactions mediated by VOCs in nature to design better control strategies for plant pathogens.
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）