Muscodor albus E-6, an endophyte of Guazuma ulmifolia making volatile antibiotics: isolation, characterization and experimental establishment in the host plant.
Muscodor albus is an endophytic fungus, represented by a number of isolates from tropical tree and vine species in several of the world's rainforests, that produces volatile organic compounds (VOCs) with antibiotic activity. A new isolate, E-6, of this organism, with unusual biochemical and biological properties, has been obtained from the branches of a mature Guazuma ulmifolia (Sterculiaceae) tree growing in a dry tropical forest in SW Ecuador. This unique organism produces many VOCs not previously observed in other M. albus isolates, including butanoic acid, 2-methyl-; butanoic acid, 3-methyl-; 2-butenal, 2-methyl-; butanoic acid, 3-methylbutyl ester; 3-buten-1-ol, 3-methyl; guaiol; 1-octene, 3-ethyl-; formamide, N-(1-methylpropyl); and certain azulene and naphthalene derivatives. Some compounds usually seen in other M. albus isolates also appeared in the VOCs of isolate E-6, including caryophyllene; phenylethyl alcohol; acetic acid, 2-phenylethyl ester; bulnesene; and various propanoic acid, 2-methyl- derivatives. The biological activity of the VOCs of E-6 appears different from the original isolate of this fungus, CZ-620, since a Gram-positive bacterium was killed, and Sclerotinia sclerotiorum and Rhizoctonia solani were not. Scanning electron micrographs of the mycelium of isolate E-6 showed substantial intertwining of the hyphal strands. These strands seemed to be held together by an extracellular matrix accounting for the strong mat-like nature of the mycelium, which easily lifts off the agar surface upon transfer, unlike any other isolate of this fungus. The ITS-5.8S rDNA partial sequence data showed 99 % similarity to the original M. albus strain CZ-620. For the first time, successful establishment of M. albus into its natural host, followed by recovery of the fungus, was accomplished in seedlings of G. ulmifolia. Overall, isolates of M. albus, including E-6, have chemical, biological and structural characteristics that make them potentially useful in medicine, agricultural and industrial applications.
Strobel
Gary A
GA
Department of Plant Sciences, Montana State University, Bozeman, MT 59717, USA.
Kluck
Katreena
K
Department of Plant Sciences, Montana State University, Bozeman, MT 59717, USA.
Hess
Wilford M
WM
Department of Plant and Animal Biology, Brigham Young University, Provo, UT 84602, USA.
Sears
Joe
J
Center for Lab Services/RJ Lee Group, 2710 North 20th Ave, Pasco, WA 99301, USA.
Ezra
David
D
Department of Plant Pathology and Weed Research, The Volcani Center, ARO, PO Box 6, Bet-Dagan 50250, Israel.
Vargas
Percy N
PN
Universidad Nacional San Antonio Abad del Cusco, Peru Escuela Post Grado, Facultad de Biologia, Andes Amazon Guianas Herbario Vargas (CUZ), Peru.
D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001203:Ascomycota / Q000187:drug effects; D001412:Bacillus subtilis / Q000187:drug effects; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004484:Ecuador; D004926:Escherichia coli / Q000187:drug effects; D020459:Genes, rRNA; D025301:Hyphae / Q000648:ultrastructure; D019660:Malvaceae / Q000382:microbiology*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D012331:RNA, Fungal / Q000235:genetics; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D012232:Rhizoctonia / Q000187:drug effects; D017422:Sequence Analysis, DNA; D014197:Trees; D013098:Xylariales / Q000737:chemistry / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D012331:RNA, Fungal; D012340:RNA, Ribosomal, 5.8S