Volatile antimicrobials from Muscodor albus, a novel endophytic fungus

Department of Plant Sciences 1 , and Department of Chemistry and Biochemistry 2 , Montana State University, Bozeman, MT 59717, USA Author for correspondence: Gary A. Strobel. Tel: +1 406 994 5148. Fax: +1 406 994 7600. e-mail: uplgs{at}montana.edu Muscodor albus is a recently described endophytic fungus obtained from small limbs of Cinnamomum zeylanicum (cinnamon tree). This xylariaceaous fungus effectively inhibits and kills certain other fungi, and bacteria, by virtue of a mixture of volatile compounds that it produces. The majority of these compounds were identified by gas chromatography/mass spectrometry and then made into an artificial mixture that mimicked the antibiotic effects of the mixture of volatile compounds given off by the fungus. Each of the five classes of volatile compounds produced by the fungus (alcohols, esters, ketones, acids and lipids) had some inhibitory effect against the test fungi and bacteria, but none was lethal. However, collectively they acted synergistically to kill a broad range of plant- and human-pathogenic fungi and bacteria. The most effective class of inhibitory compounds was the esters, of which 1-butanol, 3-methyl-, acetate was the most active biologically. This report describes the ecological implications and potential practical benefits of the ‘mycofumigation’ effects of M. albus . Keywords: endophyte, organic volatiles, pathogens, esters, aldehydes