title: Biosynthetic genes and activity spectrum of antifungal polyynes from Collimonas fungivorans Ter331.
abstract: The antifungal activity of bacteria from the genus Collimonas has been well documented, but the chemistry and gene functions that underlie this phenotype are still poorly understood. Screening of a random plasposon insertion library of Collimonas fungivorans Ter331 for loss-of-function mutants revealed the importance of gene cluster K, which is annotated to code for the biosynthesis of a secondary metabolite and which features genes for fatty acid desaturases and polyketide synthases. Mutants in gene cluster K had lost the ability to inhibit hyphal growth of the fungus Aspergillus niger and were no longer able to produce and secrete several metabolites that after extraction and partial purification from wildtype strain Ter331 were shown to share a putative ene-triyne moiety. Some but not all of these metabolites were able to inhibit growth of A. niger, indicating functional variation within this group of Collimonas-produced polyyne-like 'collimomycins'. Polymerase chain reaction analysis of isolates representing different Collimonas species indicated that the possession of cluster K genes correlated positively with antifungal ability, further strengthening the notion that this cluster is involved in collimomycin production. We discuss our findings in the context of other bacterially produced polyynes and the potential use of collimomycins for the control of harmful fungi.
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; BioDetection Systems b.v., Amsterdam, The Netherlands.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Fritsche
authors.forename: Marlies
authors.initials: M
authors.lastname: van den Berg
authors.forename: Wietse
authors.initials: W
authors.lastname: de Boer
authors.forename: Teris A
authors.initials: TA
authors.lastname: van Beek
authors.forename: Jos M
authors.initials: JM
authors.lastname: Raaijmakers
authors.forename: Johannes A
authors.initials: JA
authors.lastname: van Veen
authors.forename: Johan H J
authors.initials: JH
authors.lastname: Leveau
mesh_terms: D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001234:Aspergillus niger / Q000187:drug effects; D044943:Fatty Acid Desaturases / Q000235:genetics; D005798:Genes, Bacterial; D056265:Microbial Interactions; D042802:Oxalobacteraceae / Q000235:genetics* / Q000378:metabolism; D048630:Polyketide Synthases / Q000235:genetics; D053279:Polyynes / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D053279:Polyynes; D048630:Polyketide Synthases; D044943:Fatty Acid Desaturases