scholarly journals Biosynthetic Pathway of Pseudomonas aeruginosa 4-Hydroxy-2-Alkylquinolines

2005 ◽  
Vol 187 (11) ◽  
pp. 3630-3635 ◽  
Author(s):  
Florian Bredenbruch ◽  
Manfred Nimtz ◽  
Victor Wray ◽  
Michael Morr ◽  
Rolf Müller ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biosynthetic Pathway ◽  
Gas Chromatography Mass Spectrometry ◽  
Signal Molecules ◽  
Resonance Spectroscopy ◽  
Bacterial Communication ◽  
Homoserine Lactones ◽  
Feeding Experiments ◽  
Derivatives Of

ABSTRACT The role of intercellular communication in the regulation of bacterial multicellular behavior has received widespread attention, and a variety of signal molecules involved in bacterial communication have been discovered. In addition to the N-acyl-homoserine lactones, 4-hydroxy-2-alkylquinolines (HAQs), including the Pseudomonas quinolone signal, have been shown to function as signal molecules in Pseudomonas aeruginosa. In this study we unraveled the biosynthetic pathway of HAQs using feeding experiments with isotope-labeled precursors and analysis of extracted HAQs by gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. Our results show that the biosynthesis of various HAQ metabolites is directed via a common metabolic pathway involving a “head-to-head” condensation of anthranilic acid and β-keto fatty acids. Moreover, we provide evidence that the β-keto-(do)decanoic acids, crucial for the biosynthesis of the heptyl and nonyl derivatives of the 4-hydroxyquinolines in P. aeruginosa, are at least in part derived from a common pool of β-hydroxy(do)decanoic acids involved in rhamnolipid biosynthesis.

Growth of Salmonella Enteritidis in the presence of quorum sensing signaling compounds produced by Pseudomonas aeruginosa

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Weijia He ◽  
Huamei Yang ◽  
Xiang Wang ◽  
Hongmei Li ◽  
Qingli Dong
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Salmonella Enteritidis ◽  
Culture Supernatant ◽  
Lag Time ◽  
Bacterial Communication ◽  
Homoserine Lactones ◽  
Positive Effects ◽  
Kinetics Of

Abstract Quorum sensing (QS) can exist in food-related bacteria and potentially affect bacterial growth through acyl-homoserine lactones (AHLs). To verify the role of QS compounds in the cell-free supernatant, this study examined the effect of supernatant extracted from Pseudomonas aeruginosa culture on the growth kinetics of Salmonella Enteritidis. The results showed that the lag time (λ) of S. Enteritidis was apparently reduced (p < 0.05) under the influence of P. aeruginosa culture supernatant compared with the S. Enteritidis culture supernatant. HPLC-MS/MS test demonstrated that AHLs secreted by P. aeruginosa were mainly C14-HSL with a content of 85.71 μg/mL and a small amount of 3-oxo-C12-HSL. In addition, the commercially synthetic C14-HSL had positive effects on the growth of S. Enteritidis, confirming once again that the growth of S. Enteritidis was affected by AHL metabolized by other bacteria and the complexity of bacterial communication.

scholarly journals Oxepinamide F biosynthesis involves enzymatic d-aminoacyl epimerization, 3H-oxepin formation, and hydroxylation induced double bond migration

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Liujuan Zheng ◽  
Haowen Wang ◽  
Aili Fan ◽  
Shu-Ming Li
Keyword(s):  
Cytochrome P450 ◽  
Double Bond ◽  
Biosynthetic Pathway ◽  
Hydroxyl Group ◽  
Cytochrome P450 Enzyme ◽  
Double Bond Migration ◽  
Feeding Experiments ◽  
Aspergillus Ustus ◽  
P450 Enzyme ◽  
Derivatives Of

Abstract Oxepinamides are derivatives of anthranilyl-containing tripeptides and share an oxepin ring and a fused pyrimidinone moiety. To the best of our knowledge, no studies have been reported on the elucidation of an oxepinamide biosynthetic pathway and conversion of a quinazolinone to a pyrimidinone-fused 1H-oxepin framework by a cytochrome P450 enzyme in fungal natural product biosynthesis. Here we report the isolation of oxepinamide F from Aspergillus ustus and identification of its biosynthetic pathway by gene deletion, heterologous expression, feeding experiments, and enzyme assays. The nonribosomal peptide synthase (NRPS) OpaA assembles the quinazolinone core with d-Phe incorporation. The cytochrome P450 enzyme OpaB catalyzes alone the oxepin ring formation. The flavoenzyme OpaC installs subsequently one hydroxyl group at the oxepin ring, accompanied by double bond migration. The epimerase OpaE changes the d-Phe residue back to l-form, which is essential for the final methylation by OpaF.

scholarly journals Alginate synthesis by Pseudomonas aeruginosa: a key pathogenic factor in chronic pulmonary infections of cystic fibrosis patients.

1991 ◽  
Vol 4 (2) ◽  
pp. 191-206 ◽  
Author(s):  
T B May ◽  
D Shinabarger ◽  
R Maharaj ◽  
J Kato ◽  
L Chu ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Biosynthetic Pathway ◽  
Pulmonary Infection ◽  
Regulatory Mechanism ◽  
Regulatory Proteins ◽  
Host Immune System ◽  
Pathogenic Factor ◽  
Pulmonary Infections

Pulmonary infection by mucoid, alginate-producing Pseudomonas aeruginosa is the leading cause of mortality among patients suffering from cystic fibrosis. Alginate-producing P. aeruginosa is uniquely associated with the environment of the cystic fibrosis-affected lung, where alginate is believed to increase resistance to both the host immune system and antibiotic therapy. Recent evidence indicates that P. aeruginosa is most resistant to antibiotics when the infecting cells are present as a biofilm, as they appear to be in the lungs of cystic fibrosis patients. Inhibition of the protective alginate barrier with nontoxic compounds targeted against alginate biosynthetic and regulatory proteins may prove useful in eradicating P. aeruginosa from this environment. Our research has dealt with elucidating the biosynthetic pathway and regulatory mechanism(s) responsible for alginate synthesis by P. aeruginosa. This review summarizes reports on the role of alginate in cystic fibrosis-associated pulmonary infections caused by P. aeruginosa and provides details about the biosynthesis and regulation of this exopolysaccharide.

The role of metabolomics in personalized medicine for diabetes

2021 ◽  
Author(s):  
Shamiha Chowdhury ◽  
Sultan Mohammed Faheem ◽  
Shaik Sarfaraz Nawaz ◽  
Khalid Siddiqui
Keyword(s):  
Mass Spectrometry ◽  
Personalized Medicine ◽  
Diabetes Management ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Liquid Chromatography Mass Spectrometry ◽  
Hydroxybutyric Acid ◽  
Chromatography Mass Spectrometry ◽  
Branch Chain Amino

Metabolomics is rapidly evolving omics technology in personalized medicine, it offers a new avenue for identification of multiple novel metabolic mediators of impaired glucose tolerance and dysglycemia. Liquid chromatography–mass spectrometry, gas chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy are most commonly used analytical methods in the field of metabolomics. Recent evidences showed that metabolomic profiles are link to the incidence of diabetes. In this review, an overview of metabolomics studies in diabetes revealed several diabetes-associated metabolites including 1,5 anhydroglycitol, branch chain amino acids, glucose, α-hydroxybutyric acid, 3-hydroundecanoyl-carnitine and phosphatidylcholine that could be potential biomarkers associated with diabetes. These identified metabolites can be used to develop personalized prognostics and diagnostic, and help in diabetes management.

scholarly journals Antibacterial activity of Zataria multiflora essential oil and its main components against Pseudomonas aeruginosa

2017 ◽  
Vol 63 (3) ◽  
pp. 18-24 ◽  
Author(s):  
Mohaddese Mahboubi ◽  
Rezvan Heidarytabar ◽  
Elaheh Mahdizadeh
Keyword(s):  
Gas Chromatography ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Zataria Multiflora ◽  
Main Components

Summary Introduction: In Iranian traditional medicine, Zataria multiflora Boiss (Lamiaceae family) is reputed due to its antiseptic effects. Objective: The purpose of this study was to evaluate the antibacterial and biofilm killing effects of Z. multiflora essential oil and main components against Pseudomonas aeruginosa. Methods: The main components of essential oil were identified by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antibacterial properties of Z. multiflora oil and main components were determined by assessing the MIC and MBC values, and their inhibition percent of biofilm killing effects were determined by the evaluation of optical density. The role of each main component in these activities was determined according to the chemical profiles of essential oil. Results: Thymol (38.7%), carvacrol (30.6%), and p-cymene (8.3%) were main components of twenty five components of essential oil. Carvacrol had the higher role in antibacterial activity against P. aeruginosa, followed by thymol. P-cymene enhanced the antibacterial activities of thymol and carvacrol against P. aeruginosa. Carvacrol showed the weak role in biofilm killing effect. In spite of the low antibacterial activity of p-cymene against P. aeruginosa, it can enhance the antibacterial activity of thymol or carvacrol. Conclusion: Z. multiflora essential oil can be used for the management of P. aeruginosa infections. Determining the precise role of each components needs investigating in their behavior in different media.

scholarly journals Sclareol and linalyl acetate are produced by glandular trichomes through the MEP pathway

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Camille Chalvin ◽  
Stéphanie Drevensek ◽  
Françoise Gilard ◽  
Caroline Mauve ◽  
Christel Chollet ◽  
...  
Keyword(s):  
Cellular Localization ◽  
Biosynthetic Pathway ◽  
Enzyme Inhibitors ◽  
Glandular Trichomes ◽  
Ionization Mass ◽  
Specialized Metabolites ◽  
Methylerythritol Phosphate ◽  
Feeding Experiments ◽  
Salvia Sclarea

AbstractSclareol, an antifungal specialized metabolite produced by clary sage, Salvia sclarea, is the starting plant natural molecule used for the hemisynthesis of the perfume ingredient ambroxide. Sclareol is mainly produced in clary sage flower calyces; however, the cellular localization of the sclareol biosynthesis remains unknown. To elucidate the site of sclareol biosynthesis, we analyzed its spatial distribution in the clary sage calyx epidermis using laser desorption/ionization mass spectrometry imaging (LDI–FTICR-MSI) and investigated the expression profile of sclareol biosynthesis genes in isolated glandular trichomes (GTs). We showed that sclareol specifically accumulates in GTs’ gland cells in which sclareol biosynthesis genes are strongly expressed. We next isolated a glabrous beardless mutant and demonstrate that more than 90% of the sclareol is produced by the large capitate GTs. Feeding experiments, using 1-13C-glucose, and specific enzyme inhibitors further revealed that the methylerythritol-phosphate (MEP) biosynthetic pathway is the main source of isopentenyl diphosphate (IPP) precursor used for the biosynthesis of sclareol. Our findings demonstrate that sclareol is an MEP-derived diterpene produced by large capitate GTs in clary sage emphasing the role of GTs as biofactories dedicated to the production of specialized metabolites.

Dolichol: a curriculum cognitionis

1992 ◽  
Vol 70 (6) ◽  
pp. 377-381 ◽  
Author(s):  
Frank W. Hemming
Keyword(s):  
Biosynthetic Pathway ◽  
Side Chain ◽  
Plant Tissues ◽  
Animal Tissues ◽  
Dolichyl Phosphate ◽  
Putative Precursor ◽  
Eukaryotic Organisms ◽  
Derivatives Of ◽  
Long Chain

Dolichols were first described about 30 years ago when animal tissues were being examined for the presence of a putative precursor to the polyisoprenoid side chain of ubiquinone. These long-chain 2,3-dihydro-polycis-isoprenoid alcohols are found in all eukaryotic organisms. In many plant tissues they are accompanied by families of other polyisoprenoid alcohols that are usually similar molecules and possess an unsaturated α-isoprene residue. Analogy with the role of bactoprenyl phosphates in the synthesis of bacterial wall glycans led to the discovery that the mono- and di-phosphates of dolichols function as cofactors in protein N-glycosylation, involving the formation of glycosylated derivatives of dolichol as intermediates. Variation of the concentration of dolichyl phosphate was shown to be one way of controlling protein N-glycosylation. This can be achieved by modification of the relative activities of dolichol kinase and dolichol phosphate phosphatase. Modulation of the biosynthetic pathway, still not fully understood, of dolichyl phosphate may also be an important factor. Several disease conditions involve aberrations in these pathways.Key words: dolichols, polyisoprenoid alcohols, N-glycosylation, O-mannosylation.

Pyrite-enhanced degradation of chloramphenicol by low concentrations of H2O2

2015 ◽  
Vol 72 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Deli Wu ◽  
Yanxia Liu ◽  
Zhiyong Zhang ◽  
Luming Ma ◽  
Yalei Zhang
Keyword(s):  
Energy Dispersive Spectrometry ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Low Concentrations ◽  
Spin Resonance ◽  
Initial Ph ◽  
Catalyzed Reactions ◽  
Natural Pyrite ◽  
Enhanced Degradation

A pyrite-catalyzed reaction was used to degrade chloramphenicol. Chloramphenicol could be almost 100% removed within 60 minutes when 1 mM H2O2 and 0.1 g/L pyrite were added at an initial pH = 3. During oxidation, intermediates such as nitrobenzaldehyde and dichloroacetamide were identified by gas chromatography/mass spectrometry (GC/MS). The •OH was identified by electron spin-resonance spectroscopy. Pyrite was digested to determine elements by ICP (inductive coupled plasma emission spectrometer). To understand the reaction mechanism and the role of natural pyrite in these processes, techniques including scanning electron microscopy and energy dispersive spectrometry were employed to characterize the solid sample. The results explain that pyrite acts as a ‘bond’ between Fe3+ and H2O2, and this pathway continues to form •OH and inhibit the quenching reaction. Therefore, pyrite-catalyzed reactions would proceed even in low concentrations of H2O2.

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