Muscodor albusstrain GBA, an endophytic fungus ofGinkgo bilobafrom 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.

Antimicrobial activity of endophytic fungi from olive tree leaves

“…Endophytic fungi are one of the potential sources of novel antimicrobial compounds, due to chemical diversity of their secondary metabolites. So far, studies reported a wide range of novel antimicrobial compounds produced by endophytic fungi belonging to diverse structural classes, including alkaloids, peptides, steroids, terpenoids, phenols, phenylpropanoids, aliphatic compounds, polyketides, quinones and flavonoids (Mousa and Raizada 2013;Yu et al 2010), as well as volatile organic compounds (VOCs) such as esters, lipids, alcohols, acids, ketones, among others (Banerjee et al 2010;Kudalkar et al 2012). However, several studies have shown that the plant host, and ultimately its metabolism, influences the synthetic ability of endophytes (Strobel 2006;Ul-Hassan et al 2012), which could prevent these microorganisms from being used in a commercial production of antimicrobial compounds (Kusari et al 2014).…”

The same host but a different Muscodor: A new Muscodor albus isolate from wild pineapple (Ananas ananassoides) with potential application in agriculture

“…These traits clearly distinguished the isolate aa3 from the reddish colonies of M. crispans (Mitchell et al, 2008), M. roseus (Worapong et al, 2002), M. oryzae and M. suthepensis (Suwannarach et al, 2013), and from the odd cauliflower-like structures present in M. crispans (Mitchell et al, 2008), M. cinnamomi (Suwannarach et al, 2010), M. tigerii (Saxena et al, 2015) and M. darjeelingensis ; and also the bud like structure described for M. strobelii . However, aa3 hyphae resembled those earlier depicted for M. albus (Banerjee et al, 2014(Banerjee et al, , 2010Ezra et al, 2004;Strobel et al, 2007Strobel et al, , 2001. Analyses of VOCs composition demonstrated that the isolate aa3 produces naphthalene and azulene derivatives (e.g.…”

“…Volatiles of M. albus exert a strong biocide action against this bacterium (Atmosukarto et al, 2005;Banerjee et al, 2010;Ezra et al, 2004;Strobel et al, 2007), whereas those produced by M. crispans only show a weak activity (Mitchell et al, 2010). Therefore, all the evidence shows that the isolate aa3 is a new strain of M. albus, i.e.…”

“…Several strains of M. albus have been isolated from tropical trees and vine species around the world (Atmosukarto et al, 2005;Banerjee et al, 2014Banerjee et al, , 2010Ezra et al, 2004;Sopalun et al, 2003;Strobel et al, 2007Strobel et al, , 2001, indicating a wide distribution range of this species. In contrast, M. crispans has been merely isolated from an Ananas ananassoides (Baker) L.B.Sm (wild pineapple) plant found in the Bolivian Amazon (Mitchell et al, 2008).…”

Existence of Muscodor vitigenus, M. equiseti and M. heveae sp. nov. in leaves of the rubber tree (Hevea brasiliensis Müll.Arg.), and their biocontrol potential

“…All species are prevalent in Thailand except M. albus cz620. However, previous reports have shown that there are many isolates of M. albus in local host plants in many countries (Ezra et al 2004;Atmosukarto et al 2005;Strobel et al 2007;Banerjee et al 2010). One such isolate is M. albus MFC2, which has been isolated from Myristica fragrans in Thailand and produced bulnesene, ledol, (−)-globulol and azulene derivatives as major volatiles (Sopalun et al 2003).…”