Identifications of Surfactin-Type Biosurfactants Produced by <i>Bacillus</i> Species Isolated from Rhizosphere of Vegetables
Attila Bartal,
Thu Huynh,
Anita Kecskeméti,
Mónika Vörös,
Orsolya Kedves,
Henrietta Allaga,
Mónika Varga,
László Kredics,
Csaba Vágvölgyi,
András Szekeres
Affiliations
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
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
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.
