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Bartal A, Huynh T, Kecskeméti A, Vörös M, Kedves O, Allaga H, Varga M, Kredics L, Vágvölgyi C, Szekeres A. Identifications of Surfactin-Type Biosurfactants Produced by Bacillus Species Isolated from Rhizosphere of Vegetables. Molecules 2023; 28:molecules28031172. [PMID: 36770839 PMCID: PMC9919572 DOI: 10.3390/molecules28031172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/26/2023] Open
Abstract
Surfactins are cyclic lipopeptides consisting of a β-hydroxy fatty acid of variable chain length and a peptide ring of seven amino acids linked together by a lactone bridge, forming the cyclic structure of the peptide chain. These compounds are produced mainly by Bacillus species and are well regarded for their antibacterial, antifungal, and antiviral activities. For their surfactin production profiling, several Bacillus strains isolated from vegetable rhizospheres were identified by their fatty acid methyl ester profiles and were tested against phytopathogen bacteria and fungi. The isolates showed significant inhibition against of E. amylovora, X. campestris, B. cinerea, and F. culmorum and caused moderate effects on P. syringae, E. carotovora, A. tumefaciens, F. graminearum, F. solani, and C. gloeosporioides. Then, an HPLC-HESI-MS/MS method was applied to simultaneously carry out the quantitative and in-depth qualitative characterisations on the extracted ferment broths. More than half of the examined Bacillus strains produced surfactin, and the MS/MS spectra analyses of their sodiated precursor ions revealed a total of 29 surfactin variants and homologues, some of them with an extremely large number of peaks with different retention times, suggesting a large number of variations in the branching of their fatty acid chains.
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Affiliation(s)
- Attila Bartal
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
| | - Thu Huynh
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
- Department of Biotechnology, Faculty of Chemical Engineering, Ho Chi Minh University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 72607, Vietnam
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 71351, Vietnam
| | - Anita Kecskeméti
- Department of Biotechnology, Faculty of Chemical Engineering, Ho Chi Minh University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 72607, Vietnam
| | - Mónika Vörös
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
| | - Orsolya Kedves
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
| | - Henrietta Allaga
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
| | - Mónika Varga
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
| | - László Kredics
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
| | - Csaba Vágvölgyi
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
| | - András Szekeres
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, H-6726 Szeged, Hungary
- Correspondence: ; Tel.: +36-62-544516
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Vahidinasab M, Adiek I, Hosseini B, Akintayo SO, Abrishamchi B, Pfannstiel J, Henkel M, Lilge L, Voegele RT, Hausmann R. Characterization of Bacillus velezensis UTB96, Demonstrating Improved Lipopeptide Production Compared to the Strain B. velezensis FZB42. Microorganisms 2022; 10:2225. [PMID: 36363818 PMCID: PMC9693074 DOI: 10.3390/microorganisms10112225] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 08/24/2023] Open
Abstract
Bacillus strains can produce various lipopeptides, known for their antifungal properties. This makes them attractive metabolites for applications in agriculture. Therefore, identification of productive wild-type strains is essential for the development of biopesticides. Bacillus velezensis FZB42 is a well-established strain for biocontrol of plant pathogens in agriculture. Here, we characterized an alternative strain, B. velezensis UTB96, that can produce higher amounts of all three major lipopeptide families, namely surfactin, fengycin, and iturin. UTB96 produces iturin A. Furthermore, UTB96 showed superior antifungal activity towards the soybean fungal pathogen Diaporthe longicolla compared to FZB42. Moreover, the additional provision of different amino acids for lipopeptide production in UTB96 was investigated. Lysine and alanine had stimulatory effects on the production of all three lipopeptide families, while supplementation of leucine, valine and isoleucine decreased the lipopeptide bioproduction. Using a 45-litre bioreactor system for upscaling in batch culture, lipopeptide titers of about 140 mg/L surfactin, 620 mg/L iturin A, and 45 mg/L fengycin were achieved. In conclusion, it becomes clear that B. velezensis UTB96 is a promising strain for further research application in the field of agricultural biological controls of fungal diseases.
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Affiliation(s)
- Maliheh Vahidinasab
- Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Isabel Adiek
- Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Behnoush Hosseini
- Department of Phytopathology (360a), Institute of Phytomedicine, Faculty of Agricultural Sciences, University of Hohenheim, Otto-Sander-Str. 5, 70599 Stuttgart, Germany
| | - Stephen Olusanmi Akintayo
- Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Bahar Abrishamchi
- Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Jens Pfannstiel
- Core Facility Hohenheim, Mass Spectrometry Unit, University of Hohenheim, August-von-Hartmann-Str. 3, 70599 Stuttgart, Germany
| | - Marius Henkel
- Cellular Agriculture, TUM School of Life Science, Technical University of Munich, Gregor-Mendel-Str. 4, 85354 Freising, Germany
| | - Lars Lilge
- Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Ralf T. Voegele
- Department of Phytopathology (360a), Institute of Phytomedicine, Faculty of Agricultural Sciences, University of Hohenheim, Otto-Sander-Str. 5, 70599 Stuttgart, Germany
| | - Rudolf Hausmann
- Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
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McCann A, Kune C, Massonnet P, Far J, Ongena M, Eppe G, Quinton L, De Pauw E. Cyclic Peptide Protomer Detection in the Gas Phase: Impact on CCS Measurement and Fragmentation Patterns. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:851-858. [PMID: 35467879 DOI: 10.1021/jasms.2c00035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
With the recent improvements in ion mobility resolution, it is now possible to separate small protomeric tautomers, called protomers. In larger molecules above 1000 Da such as peptides, a few studies suggest that protomers do exist as well and may contribute to their gas-phase conformational heterogeneity. In this work, we observed a CCS distribution that can be explained by the presence of protomers of surfactin, a small lipopeptide with no basic site. Following preliminary density functional theoretical calculations, several protonation sites in the gas phase were energetically favorable in positive ionization mode. Experimentally, at least three near-resolved IM peaks were observed in positive ionization mode, while only one was detected in negative ionization mode. These results were in good agreement with the DFT predictions. CID breakdown curve analysis after IM separation showed different inflection points (CE50) suggesting that different intramolecular interactions were implied in the stabilization of the structures of surfactin. The fragment ratio observed after collision-induced fragmentation was also different, suggesting different ring-opening localizations. All these observations support the presence of protomers on the cyclic peptide moieties of the surfactin. These data strongly suggest that protomeric tautomerism can still be observed on molecules above 1000 Da if the IM resolving power is sufficient. It also supports that the proton localization involves a change in the 3D structure that can affect the experimental CCS and the fragmentation channels of such peptides.
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Affiliation(s)
- Andréa McCann
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Christopher Kune
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Philippe Massonnet
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
- Maastricht Multimodal Molecular Imaging (M4I) Institute, Division of Imaging Mass Spectrometry, 6229ER Maastricht, Limburg, The Netherlands
| | - Johann Far
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Marc Ongena
- Gembloux Agro-Bio Tech, University of Liege, 5030 Gembloux, Belgium
| | - Gauthier Eppe
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Loïc Quinton
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
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Quintero M, Blandón LM, Vidal OM, Guzman JD, Gómez-Marín JE, Patiño AD, Molina DA, Puerto-Castro GM, Gómez-León J. In vitro biological activity of extracts from marine bacteria cultures against Toxoplasma gondii and Mycobacterium tuberculosis. J Appl Microbiol 2021; 132:2705-2720. [PMID: 34856041 DOI: 10.1111/jam.15397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/07/2021] [Accepted: 11/29/2021] [Indexed: 11/29/2022]
Abstract
AIMS To evaluate the biological activity of extracts from cultures of marine bacteria against Toxoplasma gondii and Mycobacterium tuberculosis. METHODS AND RESULTS Ethyl acetate extracts obtained from seven marine bacteria were tested against T. gondii GFP-RH and M. tuberculosis H37Rv. The cytotoxicity on HFF-1 cells was measured by a microplate resazurin fluorescent approach, and the haemolytic activity was determined photometrically. The extracts from Bacillus sp. (INV FIR35 and INV FIR48) affected the tachyzoite viability. The extracts from Bacillus, Pseudoalteromonas, Streptomyces and Micromonospora exhibited effects on infection and proliferation processes of parasite. Bacillus sp. INV FIR48 extract showed an minimum inhibitory concentration value of 50 µg ml-1 against M. tuberculosis H37Rv. All the extracts exhibited relatively low toxicity to HFF-1 cells and the primary culture of erythrocytes, except Bacillus sp. INV FIR35, which decreased cell viability under 20%. Liquid chromatography coupled to mass spectrometry analysis of the most active bacterial extract Bacillus sp. INV FIR48 showed the presence of peptide metabolites related to surfactin. CONCLUSIONS The extract from culture of deep-sea Bacillus sp. INV FIR48 showed anti-T. gondii and anti-tuberculosis (TB) biological activity with low cytotoxicity. In addition, peptide metabolites were detected in the extract. SIGNIFICANCE AND IMPACT OF THE STUDY Toxoplasmosis and TB are among the most prevalent diseases worldwide, and the current treatment drugs exhibit side effects. This study confirm that marine bacteria are on hand sources of anti-infective natural products.
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Affiliation(s)
- Marynes Quintero
- Marine Bioprospecting Line, Evaluation and Use of Marine and Coastal Resources Program-VAR, Marine and Coastal Research Institute-INVEMAR, Santa Marta, Colombia
| | - Lina M Blandón
- Marine Bioprospecting Line, Evaluation and Use of Marine and Coastal Resources Program-VAR, Marine and Coastal Research Institute-INVEMAR, Santa Marta, Colombia
| | - Oscar M Vidal
- Division of Health Sciences, Medicine Department, Universidad del Norte, Barranquilla, Colombia
| | - Juan D Guzman
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany
| | - Jorge E Gómez-Marín
- GEPAMOL, Center for Biomedical Research, Faculty of Health Sciences, Universidad del Quindío, Armenia, Colombia
| | - Albert D Patiño
- Marine Bioprospecting Line, Evaluation and Use of Marine and Coastal Resources Program-VAR, Marine and Coastal Research Institute-INVEMAR, Santa Marta, Colombia
| | - Diego A Molina
- GEPAMOL, Center for Biomedical Research, Faculty of Health Sciences, Universidad del Quindío, Armenia, Colombia
| | - Gloria M Puerto-Castro
- Red Nacional de Investigación Innovación y Gestión del Conocimiento en Tuberculosis, Instituto Nacional de Salud, Bogotá, Colombia
| | - Javier Gómez-León
- Marine Bioprospecting Line, Evaluation and Use of Marine and Coastal Resources Program-VAR, Marine and Coastal Research Institute-INVEMAR, Santa Marta, Colombia
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Soussi S, Essid R, Karkouch I, Saad H, Bachkouel S, Aouani E, Limam F, Tabbene O. Effect of Lipopeptide-Loaded Chitosan Nanoparticles on Candida albicans Adhesion and on the Growth of Leishmania major. Appl Biochem Biotechnol 2021; 193:3732-3752. [PMID: 34398423 DOI: 10.1007/s12010-021-03621-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/12/2021] [Indexed: 01/12/2023]
Abstract
Cyclic lipopeptides produced by Bacillus species exhibit interesting therapeutic potential. However, their clinical use remains limited due to their low stability, undesirable interactions with host macromolecules, and their potential toxicity to mammalian cells. The present work aims to develop suitable lipopeptide-loaded chitosan nanoparticles with improved biological properties and reduced toxicity. Surfactin and bacillomycin D lipopeptides produced by Bacillus amyloliquefaciens B84 strain were loaded onto chitosan nanoparticles by ionotropic gelation process. Nanoformulated lipopeptides exhibit an average size of 569 nm, a zeta potential range of 38.8 mV, and encapsulation efficiency (EE) of 85.58%. Treatment of Candida (C.) albicans cells with encapsulated lipopeptides induced anti-adhesive activity of 81.17% and decreased cell surface hydrophobicity (CSH) by 25.53% at 2000 µg/mL. Nanoformulated lipopeptides also induced antileishmanial activity against Leishmania (L.) major promastigote and amastigote forms at respective IC50 values of 14.37 µg/mL and 22.45 µg/mL. Nanoencapsulated lipopeptides exerted low cytotoxicity towards human erythrocytes and Raw 264.7 macrophage cell line with respective HC50 and LC50 values of 770 µg/mL and 234.56 µg/mL. Nanoencapsulated lipopeptides could be used as a potential delivery system of lipopeptides to improve their anti-adhesive effect against C. albicans cells colonizing medical devices and their anti-infectious activity against leishmania.
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Affiliation(s)
- Siwar Soussi
- Laboratoire Des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria (CBBC), BP-901, 2050, Hammam-lif, Tunisia.,Faculté Des Sciences de Bizerte, Université de Carthage, Tunis, Tunisia
| | - Rym Essid
- Laboratoire Des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria (CBBC), BP-901, 2050, Hammam-lif, Tunisia
| | - Ines Karkouch
- Laboratoire Des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria (CBBC), BP-901, 2050, Hammam-lif, Tunisia
| | - Houda Saad
- Laboratoire Des Matériaux Composites Et Minéraux Argileux, Centre National Des Recherches en Sciences Des Matériaux, BP-73, 8027, Soliman, Tunisia
| | - Sarra Bachkouel
- Centre de Biotechnologie de Borj-Cedria (CBBC), Espace D'Appui À La Recherche Et de Transfert Technologique, BP-901, 2050, Hammam-lif, Tunisia
| | - Ezzedine Aouani
- Laboratoire Des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria (CBBC), BP-901, 2050, Hammam-lif, Tunisia
| | - Ferid Limam
- Laboratoire Des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria (CBBC), BP-901, 2050, Hammam-lif, Tunisia
| | - Olfa Tabbene
- Laboratoire Des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria (CBBC), BP-901, 2050, Hammam-lif, Tunisia.
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Molecular Network and Culture Media Variation Reveal a Complex Metabolic Profile in Pantoea cf. eucrina D2 Associated with an Acidified Marine Sponge. Int J Mol Sci 2020; 21:ijms21176307. [PMID: 32878176 PMCID: PMC7504411 DOI: 10.3390/ijms21176307] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 01/07/2023] Open
Abstract
The Gram-negative Pantoea eucrina D2 was isolated from the marine sponge Chondrosia reniformis. Sponges were collected in a shallow volcanic vents system in Ischia island (South Italy), influenced by CO2 emissions and lowered pH. The chemical diversity of the secondary metabolites produced by this strain, under different culture conditions, was explored by a combined approach including molecular networking, pure compound isolation and NMR spectroscopy. The metabolome of Pantoea cf. eucrina D2 yielded a very complex molecular network, allowing the annotation of several metabolites, among them two biosurfactant clusters: lipoamino acids and surfactins. The production of each class of metabolites was highly dependent on the culture conditions, in particular, the production of unusual surfactins derivatives was reported for the first time from this genus; interestingly the production of these metabolites only arises by utilizing inorganic nitrogen as a sole nitrogen source. Major components of the extract obtained under standard medium culture conditions were isolated and identified as N-lipoamino acids by a combination of 1D and 2D NMR spectroscopy and HRESI-MS analysis. Assessment of the antimicrobial activity of the pure compounds towards some human pathogens, indicated a moderate activity of leucine containing N-lipoamino acids towards Staphylococcus aureus, Staphylococcus epidermidis and a clinical isolate of the emerging food pathogen Listeria monocytogenes.
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Ibrar M, Zhang H. Construction of a hydrocarbon-degrading consortium and characterization of two new lipopeptides biosurfactants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 714:136400. [PMID: 31982734 DOI: 10.1016/j.scitotenv.2019.136400] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 12/13/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
Apparent solubility and bioavailability of hydrophobic compounds are the major problems in the bioremediation process, which could be overcome by the bacteria capable of biosurfactant production and concurrent hydrocarbon degradation. In this work, we constructed an artificial bacterial consortium containing Lysinibacillus, Paenibacillus, Gordonia and Cupriavidus spp. from glyceryl tributyrate enriched bacteria collected from the non-contaminated site. The consortium was capable of using common raw materials (olive oil, paraffin oil, and glycerol) and polyaromatic hydrocarbons pollutants (naphthalene and anthracene) as the sole carbon source with simultaneous biosurfactant production. Two new lipopeptide isoforms, containing heptapeptide and lipid moieties, were structurally elucidated by LC-MS/MS, FTIR, NMR and molecular networking analysis. Our findings indicate that hydrocarbons degradation and biosurfactant production is an intrinsic property of non-contaminated soil community. Interestingly, we observed the hyper chemotactic activity of Lysinibacillus strains towards glyceryl tributyrate, which has not been reported before. The study may deepen our understanding of microbial strains and consortium with the potential to be used for bioremediation of hydrocarbons contaminated environments.
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Affiliation(s)
- Muhammad Ibrar
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei, PR China; Key Laboratory of Molecular Biophysics, Ministry of education, Wuhan, Hubei, PR China
| | - Houjin Zhang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei, PR China; Key Laboratory of Molecular Biophysics, Ministry of education, Wuhan, Hubei, PR China.
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Effects of Different Cultivation Parameters on the Production of Surfactin Variants by a Bacillus subtilis Strain. Molecules 2018; 23:molecules23102675. [PMID: 30340314 PMCID: PMC6222309 DOI: 10.3390/molecules23102675] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/16/2018] [Accepted: 10/17/2018] [Indexed: 01/30/2023] Open
Abstract
Surfactins are lipopeptide-type biosurfactants produced mainly by Bacillus species, consisting of a peptide loop of seven amino acids and a hydrophobic fatty acid chain (C12–C16). These molecules have been proven to exhibit various biological activities; thus, their therapeutic and environmental applications are considered. Within the surfactin lipopeptide family, there is a wide spectrum of different homologues and isomers; to date, more than 30 variants have been described. Since the newest members of these lipopeptides were described recently, there is no information that is available on their characteristic features, e.g., the dependence of their production from different cultivation parameters. This study examined the effects of both the different carbon sources and various metal ions on the surfactin production of a selected B. subtilis strain. Among the applied carbon sources, fructose and xylose had the highest impacts on the ratio of the different variants, regarding both the peptide sequences and the lengths of the fatty acids. Furthermore, the application of metal ions Mn2+, Cu2+ and Ni2+ in the media completely changed the surfactin variant compositions of the fermenting broths leading to the appearance of methyl esterified surfactin forms, and resulted in the appearance of novel surfactin variants with fatty acid chains containing no more than 11 carbon atoms.
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