Naphthalene, an insect repellent, is produced by Muscodor vitigenus, a novel endophytic fungus

Abstract

Muscodor vitigenus is a recently described endophytic fungus of Paullinia paullinioides, a liana growing in the understorey of the rainforests of the Peruvian Amazon. This fungus produces naphthalene under certain cultural conditions. Naphthalene produced by M. vitigenus was identified by gas chromatography/mass spectrometry. Its chromatographic and mass spectral properties were identical to authentic naphthalene. Agar plugs supporting growth of the fungus and producing known amounts of naphthalene effectively repelled the adult stage of the wheat stem sawfly, Cephus cinctus, in Y-tube bioassay tests. Authentic naphthalene, at comparable concentrations to those in tests involving the fungus itself, mimicked the insect repellency of the fungus. Although other Muscodor spp. produce volatile antimicrobials, M. vitigenus is unique in its ability to produce naphthalene almost exclusively. This report also describes the potential practical implications of M. vitigenus.

New endophytic isolates of Muscodor albus, a volatile-antibiotic-producing fungus

“…Although the VOCs appear in differing amounts and ratios, the compound in greatest abundance in all of the new isolates of M. albus is naphthalene (Table 2). This is comparable to M. vitigenus, whose only detectable VOC is naphthalene (Daisy et al, 2002b).…”

“…Interestingly, no individual compound by itself possessed major antifungal activity, but a combination of compounds was required, as was previously determined for M. albus isolate CZ-620 . It was also previously noted that naphthalene, the sole distinguishing VOC of M. vitigenus, was produced in great enough quantities to cause modifications in insect behaviour (Daisy et al, 2002b (Stinson et al, 2003a). Initially it was thought that M. albus was a unique organism confined to only one locale, but as more studies are done, it appears that it and related organisms are common inhabitants of the world's tropical rainforests.…”

“…Final identification of the VOCs was done using authentic compounds obtained commercially and synthesized Daisy et al, 2002b). At least one compound that was not available has been given a tentative identification and this is indicated in one exception, isolate TP-21, each new isolate of M. albus produced propanoic acid, 2-methyl-and the azulene derivative bulnecene.…”

Quorum sensing activity and control of yeast-mycelium dimorphism in Ophiostoma floccosum

“…Specifically in fungi, different cultures of Muscodor albus generated a mixture of volatile organic compounds the most abundant being naphthalene (Ezra et al 2004). Daisy et al (2002) also reported the production of naphthalene under certain cultural conditions by Muscodor vitigenus. Naphthalene generated by this fungus effectively repelled the adult stage of the wheat stem sawfly, Cephus cinctus.…”

Endophytes: exploitation as a tool in plant protection

“…Nodulisporic acids, novel indole diterpines, isolated from Bontia daphnoides that exhibited potent insecticidal properties against the larvae of bowl fly, worked by activating insect glutamate-gated chloride channel (Demain 2000). Daisy et al (2002) isolated another endophytic fungus, Muscodor vitigenus, from liana plant (Paullina paullinioides), which yielded naphthalene as major product. It could be used as active ingredient against common mothballs.…”