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4. Antifungal and antiprotozoal green amino acid-based rhamnolipids: Mode of action, antibiofilm efficiency and selective activity against resistant Candida spp. strains and Acanthamoeba castellanii

Author

da Silva, Anderson, Nobre, Hélio, Jr., Sampaio, Leticia, Nascimento, Bruna do, da Silva, Cecilia, de Andrade Neto, João Batista, Manresa, Ángeles, Pinazo, Aurora, Cavalcanti, Bruno, de Moraes, Manoel Odorico, Ruiz-Trillo, Iñaki, Antó, Meritxell, Morán, Carmen, and Pérez, Lourdes

Published
2020
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12. Characterization of the enzyme involved in the diol synthase metabolic pathway in Pseudomonas aeruginosa

Author

Shoja Chaghervand, S, Castells, Marc, Rabanal Anglada, Francesc, Cajal Visa, Yolanda, Manresa, Angeles, Estupiñán, Mónica, and Busquets, Montserrat

Subjects
Atomic force microscopy, Temperature, Microscòpia de força atòmica, Temperatura
Abstract

This study is the first attempt to report the biochemical characterisation of the 10S-dioxygenase (10S-DOX) and 7S, 10S-diol synthase (7,10-DS). Both enzymes showed similar pH profiles with 10S-DOX presenting the highest activity at 30 °C whereas 7,10-DS did not show a clear preferred temperature. These differences were reflected in the thermostability assay, the Km values were 0.89 ± 0.22 mM and 3.26 ± 0.31 mM for 10S-DOX and 7,10-DS, respectively. Inductively coupled plasma mass spectrometry indicated that both enzymes contained bound to haem group Fe2+ as a prosthetic group: 10S-DOX (0.95 mol Fe2+/mol of protein) and 7,10-DS (1.18 mol Fe2+/mol of protein), respectively. Assays using metal cations as cofactors revealed that Mg2+ and Ni2+ enhance 7,10-DS activity, whereas Hg2+ decrease it up to 50 %. The activity of 10S-DOX in the presence of Mn2+ and Fe2+ was reduced to 51.6 % and 61.8. Aggregated proteins producing 10S-DOX and 7,10-DS were characterised as inclusion bodies: IBs-77 and IBs-78 respectively, was performed by Fourier Transform spectroscopy (FT-IR), Atomic Force Microscopy, dye binding, and proteolysis. The specific activity was 1.55 IU/mg for IBs-77 and 1.05 IU/mg for IBs-78. The presence of the oleate-diol synthase pathway in proteobacteria other than Pseudomonas aeruginosa was detected.

Published
2022

41. Isolation and characterization of kurstakin and surfactin isoforms produced by Enterobacter cloacae C3 strain.

Author

Jemil, Nawel, Hmidet, Noomen, Manresa, Angeles, Rabanal, Francesc, and Nasri, Moncef

Subjects
THIN layer chromatography, SURFACTIN, ENTEROBACTER cloacae, GRAM-negative bacteria, CANDIDA albicans, MASS spectrometry
Abstract

In this work, the extraction, structural analysis, and identification as well as antimicrobial, anti-adhesive, and antibiofilm activities of lipopeptides produced by Enterobacter cloacae C3 strain were studied. A combination of chromatographic and spectroscopic techniques offers opportunities for a better characterization of the biosurfactant structure. Thin layer chromatography (TLC) and HPLC for amino acid composition determination are used. Efficient spectroscopic techniques have been utilized for investigations on the biochemical structure of biosurfactants, such as Fourier transform infrared (FT-IR) spectroscopy and mass spectrometry analysis. This is the first work describing the production of different isoforms belonging to kurstakin and surfactin families by E cloacae strain. Three kurstakin homologues differing by the fatty acid chain length from C10 to C12 were detected. The spectrum of lipopeptides belonging to surfactin family contains various isoforms differing by the fatty acid chain length as well as the amino acids at positions four and seven. Lipopeptide C3 extract exhibited important antibacterial activity against Gram-positive and Gramnegative bacteria, antifungal activity, and interesting anti-adhesive and disruptive properties against biofilm formation by human pathogenic bacterial strains: Salmonella typhimurium, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus cereus, and Candida albicans. [ABSTRACT FROM AUTHOR]

Published
2019
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46. Liquid chromatography/tandem mass spectrometric analysis of 7,10-dihydroxyoctadecenoic acid, its isotopomers, and other 7,10-dihydroxy fatty acids formed by Pseudomonas aeruginosa 42A2

Author

Nilsson, Tomas, Martínez, Eriel, Manresa, Angeles, Oliw, Ernst H., Nilsson, Tomas, Martínez, Eriel, Manresa, Angeles, and Oliw, Ernst H.

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen, which oxidizes oleic acid to 7(S),10(S)-dihydroxy-8(E)-octadecenoic acid (7,10-(OH)(2)-18:1) of biological and industrial interest. Electrospray tandem mass spectrometric (MS/MS) analysis of hydroxylated fatty acids usually generates characteristic fragments containing the carboxylate anion and formed by alpha-cleavage at the oxidized carbon. These fragments indicate the positions of the hydroxyl group. In contrast, liquid chromatography (LC)/MS/MS analysis of 7,10-(OH)(2)-18:1 yielded a series of other ions with structural information. To study the fragmentation mechanism, we prepared (2)H- and (18)O-labeled isotopomers. We also performed MS(3) analysis of the major ions, and for comparison we generated the corresponding 7,10-dihydroxy metabolites of 16:1n-7, 18:2n-6, and 20:1n-11 with a protein extract of P. aeruginosa. The MS/MS spectra of 7,10-(OH)(2)-18:1 and its isotopomers, 7,10-(OH)(2)-16:1, and 7,10-(OH)(2)-20:1, contained a series of prominent fragments that all hold the omega end. The 8,9-double bond was not essential for this fragmentation, as 7,10-(OH)(2)-18:0, and its isotopomers, formed essentially the same fragments in the lower mass range. In contrast, 7,10-dihydroxy-8(E),12(Z)-octadecadienoic acid (7,10-(OH)(2)-18:2) fragmented by alpha-cleavage at the oxidized carbons with formation of carboxylate anions. Our results demonstrate that C(16)-C(20) fatty acids with a 7,10-dihydroxy-8(E) functionality undergo charge-driven fragmentation after charge migration to the omega-end, whereas the main ions of 7,10-(HO)(2)-18:2 retain charge at the carboxyl group.

Published
2010
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48. Purification and identification of Bacillus subtilis SPB1 lipopeptide biosurfactant exhibiting antifungal activity against Rhizoctonia bataticola and Rhizoctonia solani.

Author

Mnif, Inès, Grau-Campistany, Ariadna, Coronel-León, Jonathan, Hammami, Inès, Triki, Mohamed, Manresa, Angeles, and Ghribi, Dhouha

Subjects
BACILLUS subtilis, BIOSURFACTANTS, ANTIFUNGAL agents, RHIZOCTONIA solani, MICROBIAL sensitivity tests
Abstract

This study reports the potential of a soil bacterium, Bacillus subtilis strain SPB1, to produce lipopeptide biosurfactants. Firstly, the crude lipopeptide mixture was tested for its inhibitory activity against phytopathogenic fungi. A minimal inhibitory concentration (MIC), an inhibitory concentration at 50 % (IC50 %), and an inhibitory concentration at 90 % (IC90 %) values were determined to be 0.04, 0.012, and 0.02 mg/ml, respectively, for Rhizoctonia bataticola with a fungistatic mode of action. For Rhizoctonia solani, a MIC, an IC50 %, and IC90 % values were determined to be 4, 0.25, and 3.3 mg/ml, respectively, with a fungicidal mode of action. For both of the fungi, a loss of sclerotial integrity, granulation and fragmentation of hyphal mycelia, followed by hyphal shriveling and cell lysis were observed with the treatment with SPB1 biosurfactant fraction. After extraction, separation, and purification, different lipopeptide compounds were identified in the culture filtrate of strain SPB1. Mass spectroscopic analysis confirmed the presence of different lipopeptide compounds consisting of surfactin isoforms with molecular weights of 1007, 1021, and 1035 Da; iturin isoforms with molecular weights of 1028, 1042, and 1056 Da; and fengycin isoforms with molecular weights of 1432 and 1446 Da. Two new clusters of lipopeptide isoforms with molecular weights of 1410 and 1424 Da and 973 and 987 Da, respectively, were also detected. This study reported the ability of a B. subtilis strain to co-produce lipopeptide isoforms with potential use as antifungal compounds. [ABSTRACT FROM AUTHOR]

Published
2016
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