Muscodor albus strain GBA, an endophytic fungus of Ginkgo biloba from United States of America, produces volatile antimicrobials

Abstract

Muscodor albus strain GBA is a newly isolated endophytic fungus from Ginko biloba (family Ginkoaceae) collected in Newport, RI, USA. The cultural characteristics (color, growth pattern) and mycelial/hyphal characteristics resemble many isolates of Muscodor albus. The ITS rDNA sequence of the strain has at least 98% similarity with other isolates of M. albus and M. crispans. This xylariaceaous species effectively inhibits and kills certain test microbes via a mixture of volatile organic compounds (VOCs) that it produces. Some of the target test microbes were totally inhibited by M. albus strain GBA and not by other M. albus isolates, making this isolate unique in its biological activity. The VOCs of this fungus were identified by gas chromatography/mass spectrometry as esters, lipids, alcohols, acids and ketones, including proportionally large quantities of 1-butanol, 3-methyl-, acetate. A terpenoid, not observed in other strains of this fungus, vitrene was tentatively identified in the VOCs of this organism. This is the first record of M. albus in Ginko biloba and is the first report of any M. albus strain from the United States. The organism is normally found in tropical latitudes (16° north/ south) but the plant host M. albus strain GBA is located at 41° north latitude. Most importantly, however, the discovery of M. albus in the USA has enormous implications vis-a.vis governmental regulation of M. albus for use as a biological control agent in agriculture and industry, as this organism naturally occurs in the USA. A discussion on the relationship of this taxon with its host is also included.