title: Characterization of rhamnolipids produced by non-pathogenic Acinetobacter and Enterobacter bacteria.
abstract: Rhamnolipid production by two non-pathogenic bacterial strains Acinetobacter calcoaceticus and Enterobacter asburiae, and established rhamnolipid producer Pseudomonas aeruginosa was investigated. Rhamnolipids were separated from supernatant and further purified by thin-layer chromatography. Mass spectrometry with negative electrospray ionization revealed rhamnolipid homologues varying in chain length and unsaturation. Tandem mass spectrometry identified mono-rhamnolipid and di-rhamnolipid homologues containing one or two 3-hydroxy fatty acids. Several media differing in carbon (sunflower oil, glycerol and sodium citrate), nitrogen (ammonium ions, nitrate) and phosphorus (total content) source, respectively, were tested to obtain enhanced rhamnolipid production. The best production (0.56g/l) was obtained when nitrate was used as a nitrogen source. Both strains produced rhamnolipids that exhibited excellent emulsification activity with aromatic and aliphatic hydrocarbons and several plant oils. Unlike P. aeruginosa the two strains, i.e. Acinetobacter and Enterobacter, are not pathogenic to humans.
authors: Institute of Chemical Technology Prague, Department of Biotechnology, Technická 5, 166 28 Prague 6, Czech Republic.
authors: Miriam
authors: M
authors: Hošková
authors: Olga
authors: O
authors: Schreiberová
authors: Richard
authors: R
authors: Ježdík
authors: Josef
authors: J
authors: Chudoba
authors: Jan
authors: J
authors: Masák
authors: Karel
authors: K
authors: Sigler
authors: Tomáš
authors: T
authors: Rezanka
mesh_terms: D016954:Acinetobacter calcoaceticus / Q000378:metabolism*; D004754:Enterobacter / Q000378:metabolism*; D006017:Glycolipids / Q000096:biosynthesis* / Q000302:isolation & purification; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D006017:Glycolipids; C418382:rhamnolipid