title: Chemical characterization and surface properties of a new bioemulsifier produced by Pedobacter sp. strain MCC-Z.
abstract: A novel biopolymer was described in the form of an extracellular polysaccharide (EPS) by Pedobacter sp. strain MCC-Z, a member of a bacterial genus not previously described as an emulsifier producer. The new biomolecule was extracted, purified and characterized, and its surface and emulsifying properties were evaluated. The purified bioemulsifier, named Pdb-Z, showed high emulsifying activity (E24% = 64%) and reduced the surface tension of water up to 41 mN/m with a critical micelle concentration value of 2.6 mg/mL. The chemical characterization of Pdb-Z was performed using (1)H NMR, FT-IR, HPLC/MS/MS and GC/MS. Pdb-Z was found to contain 67% of carbohydrates, consisting mainly of galactose and minor quantities of talose, 30% of lipids, being pentadecanoic acid the major lipidic constituent, and 3% of proteins. The bioemulsifier was a glycolipids-protein complex with an estimated molecular mass of 10(6)Da. Furthermore, Pdb-Z emulsified pure aliphatic and aromatic hydrocarbons as well as diesel more efficiently than commercial synthetic surfactants, used for comparison. Our results suggest Pdb-Z has interesting properties for applications in remediation of hydrocarbon-contaminated environments and bioremediation processes.
authors.affiliation: Technical Unit for Environmental Characterization, Prevention, and Recovery ENEA, Via Anguillarese, 301, 00123 Rome, Italy. Electronic address: tiziana.beltrani@enea.it.
authors.forename: T
authors.initials: T
authors.lastname: Beltrani
authors.affiliation: Technical Unit for Environmental Characterization, Prevention, and Recovery ENEA, Via Anguillarese, 301, 00123 Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Chiavarini
authors.affiliation: Department of Science and Chemical Technology, Tor Vergata University, Via della Ricerca Scientifica, 1 I-00133 Rome, Italy.
authors.forename: D O
authors.initials: DO
authors.lastname: Cicero
authors.affiliation: Faculty of Mathematical, Physical and Natural Sciences, Sciences for the Conservation of Cultural Heritage, Firenze University, Viale Morgagni, 40/44, 50134 Firenze, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Grimaldi
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, 09042 Monserrato, Cagliari, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ruggeri
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, 09042 Monserrato, Cagliari, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Tamburini
authors.affiliation: Technical Unit for Environmental Characterization, Prevention, and Recovery ENEA, Via Anguillarese, 301, 00123 Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cremisini
mesh_terms: D004058:Diffusion; D045703:Emulsifying Agents / Q000737:chemistry* / Q000302:isolation & purification; D005227:Fatty Acids / Q000032:analysis; D057446:Hydrodynamics; D057927:Hydrophobic and Hydrophilic Interactions; D009005:Monosaccharides / Q000032:analysis; D060485:Pedobacter / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013500:Surface Tension
chemical_list: D045703:Emulsifying Agents; D005227:Fatty Acids; D009005:Monosaccharides
keywords: Bioemulsifier; Emulsifying activity; Hydrodynamic radius