title: Quorum sensing activity and control of yeast-mycelium dimorphism in Ophiostoma floccosum.
abstract: Quorum sensing (QS) activity in Ophiostoma fungi has not been described. We have examined the growth conditions on the control of dimorphism in Ophiostoma floccosum, an attractive biocontrol agent against blue-stain fungi, and its relationship with QS activity. In a defined culture medium with L-proline as the N source, a high inoculum size (10(7) c.f.u. ml(-1)) was the principal factor that promoted yeast-like growth. Inoculum size effect can be explained by the secretion of a QS molecule(s) (QSMs) responsible for inducing yeast morphology. QSM candidates were extracted from spent medium and their structure was determined by GC-MS. Three cyclic sesquiterpenes were found. The most abundant molecule, and therefore the principal candidate to be the QSM responsible for yeast growth of O. floccosum, was 1,1,4a-trimethyl-5,6-dimethylene-decalin (C15H24). Other two compounds were also detected.
authors.affiliation: Escuela de Ingeniería Forestal, Instituto Tecnológico de Costa Rica, Apartado Postal 159-7050, Cartago, 30101, Costa Rica, aberrocal@itcr.ac.cr.
authors.forename: Alexander
authors.initials: A
authors.lastname: Berrocal
authors.forename: Claudia
authors.initials: C
authors.lastname: Oviedo
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Nickerson
authors.forename: José
authors.initials: J
authors.lastname: Navarrete
mesh_terms: D003470:Culture Media / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D015966:Gene Expression Regulation, Fungal; D006133:Growth Substances / Q000032:analysis*; D025282:Mycelium / Q000254:growth & development*; D055156:Ophiostoma / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D053038:Quorum Sensing; D012717:Sesquiterpenes / Q000032:analysis*
chemical_list: D003470:Culture Media; D006133:Growth Substances; D012717:Sesquiterpenes