title: The utilization of gum tragacanth to improve the growth of Rhodotorula aurantiaca and the production of gamma-decalactone in large scale.
abstract: The production of gamma-decalactone and 4-hydroxydecanoic acid by the psychrophilic yeast R. aurantiaca was studied. The effect of both compounds on the growth of R. aurantiaca was also investigated and our results show that gamma-decalactone must be one of the limiting factors for its production. The addition of gum tragacanth to the medium at concentrations of 3 and 4 g/l seems to be an adequate strategy to enhance gamma-decalactone production and to reduce its toxicity towards the cell. The production of gamma-decalactone and 4-hydroxydecanoic acid was significantly higher in 20-l bioreactor than in 100-l bioreactor. By using 20 g/l of castor oil, 6.5 and 4.5 g/l of gamma-decalactone were extracted after acidification at pH 2.0 and distillation at 100 degrees C for 45 min in 20- and 100-l bioreactors, respectively. We propose a process at industrial scale using a psychrophilic yeast to produce naturally gamma-decalactone from castor oil which acts also as a detoxifying agent; moreover the process was improved by adding a natural gum.
authors.affiliation: Faculté Universitaire des Sciences Agronomiques de Gembloux, Centre Wallon de Biologie Industrielle, Unité de Bio-industries, Passage des Déportés, 2, 5030 Gembloux, Belgium. alchihab.m@fsagx.ac.be
authors.forename: Mohamed
authors.initials: M
authors.lastname: Alchihab
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Destain
authors.forename: Mario
authors.initials: M
authors.lastname: Aguedo
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Wathelet
authors.forename: Philippe
authors.initials: P
authors.lastname: Thonart
mesh_terms: D019149:Bioreactors; D003651:Decanoates / Q000378:metabolism* / Q000633:toxicity; D006170:Gum Arabic / Q000494:pharmacology; D007783:Lactones / Q000378:metabolism* / Q000633:toxicity; D011135:Polysaccharides, Bacterial / Q000494:pharmacology; D012248:Rhodotorula / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D013501:Surface-Active Agents / Q000494:pharmacology*; D014144:Tragacanth / Q000494:pharmacology*
chemical_list: C548701:4-hydroxydecanoic acid; D003651:Decanoates; D007783:Lactones; D011135:Polysaccharides, Bacterial; D013501:Surface-Active Agents; C109757:decan-4-olide; D006170:Gum Arabic; D014144:Tragacanth; C002563:xanthan gum