CHEMOSPHERE
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2020
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IF 5.778
Yingjie Wu,Luyao Ma,Qizhen Liu,Olivera Topalović,Qiong Wang,Xiaoe Yang,Ying Feng
Plant growth-promoting bacteria (PGPB) can promote root uptake and shoot accumulation of cadmium (Cd) in hyperaccumulator plants, but the mechanisms by which PGPB accelerate root-to-shoot transport of Cd is still unknown. A better understanding of these mechanisms is necessary to develop the strategies that can promote the practical phytoextraction of Cd-polluted soils. In this study, we found that Pseudomonas fluorescens accelerates a reversed and a long-distance transport of Cd and sucrose in Sedum alfredii , by examining the xylem and phloem sap and by quantifying the concentrations of Cd and sucrose in shoot and root. The transcriptome sequencing has revealed the up-regulated expressions of starch metabolism and sucrose biosynthesis related genes in the shoots of Cd hyperaccumulator plant S. alfredii that was inoculated with PGPB P. fluorescens . In addition, the genes of sugar, cation and anion transporters were also up-regulated by bacterial treatment, showing a complicated co-expression network with sucrose biosynthesis related genes. The expression levels of Cd transporter genes, such as ZIP1 , ZIP2 , HMA2 , HMA3 and CAX2 , were elevated after PGPB inoculation. As a result, the PGPB successfully colonized the root, and promoted the sucrose shoot-to-root transport and Cd root-to-shoot transport in S. alfredii. Since non-photosynthetic root-associated bacteria usually obtain sugars from photosynthetic plants, our results highlight the importance of PGPB-induced changes in hyperaccumlator plants for both the host and the PGPB.
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BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2019
·Vol. 43
·期 1
·67-73
·
IF 2.371
Xu Qianqian,Zheng Zhaojuan,Zou Lihua,Zhang Chen,Yang Fen,Zhou Kaijie,Ouyang Jia
Currently, biotransformation of 5-hydroxymethylfurfural (HMF) into a series of high-value bio-based platform chemicals is massively studied. In this study, selective biooxidation of HMF to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) by Pseudomonas putida KT2440 with superior titer, yield, and productivity was reported. The biocatalytic performances of P. putida KT2440 were optimized separately. Under optimal conditions, 100% yield of HMFCA was obtained when HMF concentration was less than 150 mM, while the maximum concentration of 155 mM was achieved from 160 mM HMF in 12 h. P. putida KT2440 was highly tolerate to HMF, up to 190 mM. Besides, it was capable of selective oxidation of other furan aldehydes to the corresponding carboxylic acids with good yield of 100%. This study further demonstrates the potential of P. putida KT2440 as a biocatalyst for biomass conversion, as this strain has been proved the capacity to convert and utilize many kinds of biomass-derived sugars and ligin-derived aromatic compounds.
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PROCESS BIOCHEMISTRY
·
2018
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IF 2.616
Feng Xue,Xiangju Ya,Qi Tong,Yuansong Xiu,He Huang
A new halohydrin dehalogenase-like gene (HHDH) in the genome of Pseudomonas umsongensis YCIT1612 was identified, cloned and over-expressed in Escherichia coli . HHDH-Pu exhibited the highest sequence identity of 45% in comparison with the previously reported HHDHs. The recombinant HHDH-Pu was purified to homogeneity and its catalytic characteristics in epoxide ring opening was explored. Compared to other reported HHDHs, HHDH-Pu showed higher catalytic activity, exhibiting varied activities (2.4–50.4 U/mg) toward all the tested epoxides. It catalyzed the ring opening of epoxides with low to moderate enantioselectivity ( E =1.13-10.89). Rac- PGE was found to be the most selective among the tested epoxides. In the ring opening of rac -PGE, nucleophiles such as Cl − , N 3 − , NO 2 − , Br − or SCN − were accepted. N 3 − was selected as the optimal nucleophile. Some parameters that may alter this bio-resolution, such as the concentration of N 3 − , temperature and pH were evaluated. By optimizing the reaction conditions, the residual ( S )-PGE could be obtained in 23.5% yield and more than 99% ee from 40 mM rac -PGE.
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INTERNATIONAL BIODETERIORATION & BIODEGRADATION
·
2015
·
IF 2.131
Yuancai Lv,Lianghao Li,Yuancai Chen,Zhenghua Tang,Yongyou Hu
Polybrominated diphenyl ethers (PBDEs) are emerging persistent organic pollutants and the degradation of PBDEs is still a tremendous challenge owing to their extreme persistence and recalcitrance. In this study, Pseudomonas putida was employed for bioremediation of four PBDE congeners (BDE47, 15, 3 and diphenyl ether (DE)) with an initial concentration of 2 mg/L and the cometabolism of PBDEs was illustrated via kinetics analysis and metabolic mechanism. The biodegradation kinetics analysis suggested that PBDEs was inversely proportional to the number of bromine substituted on diphenyl ether. Both glucose (24 mg/L) and biphenyl (10 mg/L) played a positive role in promoting the biodegradation of PBDEs. The growth kinetics analysis indicated that glucose had uncompetitive inhibition on PBDEs consumption while both competitive and uncompetitive inhibition existed in biphenyl-PBDEs binary substrate system. Furthermore, the intermediates were identified by GC–MS and the main tentative degradation pathways were proposed. The angular dioxygenation was the main pathway for PBDEs degradation, while lateral dioxygenation could be induced when biphenyl was added.
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Advanced Healthcare Materials
·
2024
·
IF 10
Yuwei Zheng,Jiaying Chi,Jiayu Ou,Ling Jiang,Liqing Wang,Rui Luo,Yilang Yan,Zejun Xu,Tingting Peng,Jianfeng Cai,Chuanbin Wu,Peng Teng,Guilan Quan,Chao Lu
The development of narrow-spectrum antimicrobial agents is paramount for swiftly eradicating pathogenic bacteria, mitigating the onset of drug resistance, and preserving the homeostasis of bacterial microbiota in tissues. Owing to the limited affinity between the hydrophobic lipid bilayer interior of bacterial cells and most hydrophilic, polar peptides, the construction of a distinctive class of four-armed host-defense peptides/peptidomimetics (HDPs) is proposed with enhanced specificity and membrane perturbation capability against Pseudomonas aeruginosa by incorporating imidazole groups. These groups demonstrate substantial affinity for unsaturated phospholipids, which are predominantly expressed in the cell membrane of P. aeruginosa , thereby enabling HDPs to exhibit narrow-spectrum activity against this bacterium. Computational simulations and experimental investigations have corroborated that the imidazole-rich, four-armed peptidomimetics exhibit notable selectivity toward bacteria over mammalian cells. Among them, 4H10, characterized by its abundant and densely distributed imidazole groups, exhibits impressive activity against various clinically isolated P. aeruginosa strains. Moreover, 4H10 has demonstrated potential as an antibiotic adjuvant, enhancing doxycycline accumulation and exerting effects on intracellular targets by efficiently disrupting bacterial cell membranes. Consequently, the hydrogel composed of 4H10 and doxycycline emerged as a promising topical agent, significantly diminishing the skin P. aeruginosa burden by 97.1% within 2 days while inducing minimal local and systemic toxicity.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Huan Du,Ji-Liang Cheng,Zhi-Yong Li,Huai-Ning Zhong,Shuang Wei,Yu-Juan Gu,Can-Can Yao,Miaoyue Zhang,Quan-Ying Cai,Hai-Ming Zhao,Ce-Hui Mo
A comprehensive understanding of the molecular mechanisms underlying microbial catabolism of dibutyl phthalate (DBP) is still lacking. Here, we newly isolated a bacterial strain identified as Pseudomonas aeruginosa PS1 with high efficiency of DBP degradation. The degradation ratios of DBP at 100–1000 mg/L by this strain reached 80–99 % within 72 h without a lag phase. A rare DBP-degradation pathway containing two monobutyl phthalate-catabolism steps was proposed based on intermediates identified by HPLC-TOF-MS/MS. In combination with genomic and transcriptomic analyses, we identified 66 key genes involved in DBP biodegradation and revealed the genetic basis for a new complete catabolic pathway from DBP to Succinyl-CoA or Acetyl-CoA in the genus Pseudomonas for the first time. Notably, we found that a series of homologous genes in Pht and Pca clusters were simultaneously activated under DBP exposure and some key intermediate degradation related gene clusters including Pht , Pca , Xyl , Ben , and Cat exhibited a favorable coexisting pattern, which contributed the high-efficient DBP degradation ability and strong adaptability to this strain. Overall, these results broaden the knowledge of the catabolic diversity of DBP in microorganisms and enhance our understanding of the molecular mechanism underlying DBP biodegradation.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Liuyuan Tang,Jing Yang,Xiaona Liu,Lingke Kang,Wenjun Li,Ting Wang,Tianwei Qian,Bo Li
Microorganisms capable of simultaneously remediating heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) pollution hold significant importance in bioremediation efforts. In this study, we investigated the ability of Pseudomonas aeruginosa AO-4 to simultaneously degrade phenanthrene (PHE) and reduce Cr (VI). Specifically, it has the ability to reduce 100 % of Cr (VI) (30 mg/L) while degrading 43.8 % of PHE (50 mg/L). In batch experiments, it was observed that the presence of Cr (VI) can enhance the degradation of PHE by strain AO-4. The solubility of PHE in soluble extracellular polymeric substances (S-EPS) was found to be related to the initial concentration of Cr (VI), which could explain why Cr (VI) promotes the degradation of PHE. Additionally, XPS analysis confirmed that Cr (VI) was reduced to Cr (III) with S-EPS produced by Pseudomonas aeruginosa AO-4. GC–MS analysis was conducted to analyze the degradation metabolites of phenanthrene, di(2-ethylhexyl) phthalate and 2TMS derivatives of salicylic acid were detected, indicating that Pseudomonas aeruginosa AO-4 is capable of degrading phenanthrene through two distinct pathways. These findings demonstrate the potential of Pseudomonas aeruginosa AO-4 in the treatment of co-contamination scenarios involving PAHs and HMs.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Shihui Yu,Jieyi Pan,Mao Xu,Yujun Chen,Pengyu Li,Haiyan Hu
Multidrug-resistant P. aeruginosa (MDR- P. aeruginosa ), associated with elevated morbidity, mortality, and readmission rates, presents a formidable challenge to eradication due to its robust resistance to antimicrobial agents and biofilm formation. Herein, self-assembling nanoparticles (NO-PE/PLL NPs) comprised of NO donor-conjugated γ-polyglutamic acid (GSNO-PGA), epsilon-poly- l -lysine (PLL) and colistin were fabricated. The negatively charged NO-PE/PLL NPs exhibited effective penetration through airway mucus, reaching the infection site where GSNO-PGA released NO in response to glutathione within biofilm. PLL worked synergistically with colistin (fractional inhibitory concentration index: 0.281), reducing the minimum inhibitory concentration (MIC) of colistin from 2 to 0.5 μg/mL. Benefiting from this synergistic antibacterial action and NO-mediated biofilm disruption, NO-PE/PLL NPs achieved a 99.99 % eradication rate against MDR- P. aeruginosa biofilms. Additionally, NO-PE/PLL NPs efficiently inhibited endotoxins-stimulated inflammation response. In a chronic pulmonary infection model, NO-PE/PLL NPs displayed the highest eradication efficiency (99.78 %) to infected mice, while having no adverse effects on their major organs or pulmonary functions. These results highlight NO-PE/PLL NPs as a promising therapeutic strategy for treating recalcitrant infections caused by MDR- P. aeruginosa biofilms.
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Phytopathology Research
·
2022
·Vol. 4
·期 1
·1-12
·
IF 3.955
Jiang Long,Xiang Shunyu,Lv Xing,Wang Xiaoyan,Li Fengwei,Liu Weina,Liu Changyun,Ran Mao,Huang Jin,Xu Xiaohong,Ma Xiaozhou,Jin Yabo,Sun Xianchao
Silver (Ag)-containing agents or materials are widely used today in plant protection for their antimicrobial activity. In view of the superior inhibitory ability of biosynthesized (aldehyde-modified sodium alginate based) silver nanoparticles (AgNPs) against plant pathogenic fungi in our previous research, here we explored the antagonistic effect of biosynthesized AgNPs on plant pathogenic bacteria and the underlying mechanism. We selected Pseudomonas syringae pv. tabaci , the causal agent of tobacco wildfire disease, as the target and found that 1.2 μg/mL biosynthesized AgNPs completely inhibited the growth of P. syringae pv. tabaci in vitro and in vivo by partly destroying the cell membrane structure of the pathogen, resulting in cytoplasmic leakage. Moreover, Nicotiana benthamiana treated with 1.2 μg/mL biosynthesized AgNPs exhibited a significant upregulation of nonexpressor of pathogenesis-related genes 1 ( NPR1 ) and pathogenesis-related gene 2 ( PR2 ), the typical markers of the salicylic acid (SA)-mediated defense system, and an increase in peroxidase (POD) and polyphenol oxidase (PPO) activities as well as the production of reactive oxygen species (ROS). Furthermore, biosynthesized AgNPs treatment increased the chlorophyll content and dry weight of N. benthamiana . Overall, we demonstrated that biosynthesized AgNPs at a low concentration have high inhibitory effect on the pathogen causing tobacco wildfire disease by destroying bacterial cell membrane and inducing defense resistance in host plant. These results lay a theoretical foundation for further application of biosynthesized AgNPs in the control of plant bacterial diseases.
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Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Zheng Qi,Chunguang Liu
Characterizing the metabolic network and dynamics of Viable But Nonculturable (VBNC) bacteria is crucial for their identification and control. In this study, single-cell Raman spectroscopy was used to explore the metabolic intricacies of VBNC P. aeruginosa induced by chlorine disinfection over 24 h. VBNC P. aeruginosa exhibited significant reductions of 75.98 %, 84.26 % and 81.07 % in carbohydrate, protein and nucleic acid Raman peaks, signaling decreased metabolic activity in these crucial components. Intriguingly, lipid metabolism in VBNC P. aeruginosa remained robust, indicating a potential adaptation to environmental stress. Furthermore, this study analyzed Raman characteristic peaks to examine metabolic conversion in these bacteria. VBNC P. aeruginosa displayed distinct phase-specific metabolic conversion patterns compared to culturable ones. These findings shed light on the temporal dynamics of metabolic processes, such as lipid-carbohydrate conversion, which appeared to be ongoing throughout the incubation period in VBNC P. aeruginosa . Compared to the culturable state, VBNC P. aeruginosa exhibited reduced isotopic assimilation rates for carbon, nitrogen and hydrogen by 40.57 %, 44.62 % and 39.45 %, indicating decreased substrate uptake for biomolecular synthesis. Additionally, the metabolic heterogeneity index of the VBNC bacterial population increased by 37.28 %, with this heterogeneity displaying a progressive increase with the duration of the culture. This observation suggests VBNC P. aeruginosa differentiation into distinct subpopulations, believed crucial for survival in challenging environments. These findings reveal the metabolic dynamics of VBNC state bacteria, providing insights into their adaptive strategies and implications for environmental health risk assessment and precise control technologies.
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FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Jingxin Ye,Weiqing Lan,Jing Xie
Exploring the roles of dominant bacteria to spoilage is important in inhibiting spoilage. This study investigated related quality, protein degradation, and muscle microstructure in refrigerated large yellow croaker inoculated with Shewanella putrefaciens (S) and Pseudomonas fluorescens (P) as mono- or co-culture (SP). P. fluorescens had the most robust spoilage ability. P. fluorescens and the co-culture degraded major myofibrillar proteins and the links to disrupt muscle fibers, induced significant free water loss in muscle and formed amounts of trichloroacetic acid (TCA)-soluble peptides and total volatile basic nitrogen (TVB-N). S. putrefaciens caused severe mutual separation in myofibers. The competitive interactions between the two spoilage bacteria inhibited spoilage in the co-culture, while the numbers of differentially abundant peptides in the co-culture were enriched. Therefore, this study revealed competitive interactions of the co-culture of S. putrefaciens and P. fluorescens , which offered a thorough understanding of bacterial spoilage behavior in large yellow croaker.
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Environmental Science-Processes & Impacts
·
2024
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IF 4.3
Caihong Wang,Qiao Ma,Jiaxin Zhang,Nan Meng,Dan Xu
Benzalkonium chloride (BAC) is a disinfectant with broad-spectrum antibacterial properties, yet despite its widespread use and detection in the environments, the effects of BAC exposure on microorganisms remain poorly documented. Herein, the impacts of BAC on a Pseudomonas aeruginosa strain Jade-X were systematically investigated. The results demonstrated that the minimum inhibitory concentration (MIC) of BAC against strain Jade-X was 64 mg/L. Exposure to BAC concentrations of 8, 16, 32, and 64 mg/L significantly augmented biofilm formation by 2.03-, 2.43-, 2.96-, and 2.56-fold respectively. The swimming and twitching abilities, along with the pyocyanin production, were inhibited. Consistently, quantitative reverse transcription PCR assays revealed significant downregulation of genes related to flagellate- and pili-mediated motilities (flgD, flgE, pilB, pilQ, and motB), as well as phzA and phzB genes involved in pyocyanin production. The results of disk diffusion and MIC assays demonstrated that BAC decreased the antibiotic susceptibility of ciprofloxacin, levofloxacin, norfloxacin, and tetracycline. Conversely, an opposite trend was observed for polymyxin B and ceftriaxone. Genomic analysis revealed that strain Jade-X harbored eleven resistance-nodulation-cell division efflux pumps, with mexCD-oprJ exhibiting significant upregulation while mexEF-oprN and mexGHI-opmD were downregulated. In addition, the quorum sensing-related regulators LasR and RhlR were also suppressed, implying that BAC might modulate the physiological and biochemical behaviors of strain Jade-X by attenuating the quorum sensing system. This study enhances our understanding of interactions between BAC and P. aeruginosa, providing valuable insights to guide the regulation and rational use of BAC.
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