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 41mN/m with a critical micelle concentration value of 2.6mg/mL. The chemical characterization of Pdb-Z was performed using 1H 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 106Da. 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. © 2014 Elsevier B.V..
Chemical characterization and surface properties of a new bioemulsifier produced by Pedobacter sp. strain MCC-Z
Beltrani, T.;Chiavarini, S.
2015-01-01
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 41mN/m with a critical micelle concentration value of 2.6mg/mL. The chemical characterization of Pdb-Z was performed using 1H 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 106Da. 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. © 2014 Elsevier B.V..I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
