Abstract
Gloeosporium sp. (OR-10) was isolated as an endophyte of Tsuga heterophylla (Western hemlock). Both ITS and 18S sequence analyses indicated that the organism best fits either Hypocrea spp. or Trichoderma spp., but neither of these organisms possess conidiophores associated with acervuli, in which case the endophytic isolate OR-10 does. Therefore, the preferred taxonomic assignment was primarily based on the morphological features of the organism as one belonging to the genus Gloeosporium sp. These taxonomic observations clearly point out that limited ITS and 18S sequence information can be misleading when solely used in making taxonomic assignments. The volatile phase of this endophyte was active against a number of plant pathogenic fungi including Phytophthora palmivora, Rhizoctonia solani, Ceratocystis ulmi, Botrytis cinerea, and Verticillium dahliae. Among several terpenes and furans, the most abundantly produced compound in the volatile phase was 6-pentyl-2H-pyran-2-one, a compound possessing antimicrobial activities. When used in conjunction with microliter amounts of any in a series of esters or isobutyric acid, an enhanced inhibitory response occurred with each test fungus that was greater than that exhibited by Gloeosporium sp. or the compounds tested individually. Compounds behaving in this manner are hereby designated “synergistans.” An expression of the “median synergistic effect,” under prescribed conditions, has been termed the mSE50. This value describes the amount of a potential synergistan that is required to yield an additional median 50 % inhibition of a target organism. In this report, the mSE50s are reported for a series of esters and isobutyric acid. The results indicated that isoamyl acetate, allyl acetate, and isobutyric acid generally possessed the lowest mSE50 values. The value and potential importance of these microbial synergistic effects to the microbial environment are also discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ahamed A, Ahring BK (2011) Production of hydrocarbon compounds by endophytic fungi Gliocladium sp. grown on cellulose. Bioresour Technol 102:9718–9722
Altschul SF, Madden TL, Schaffer AA, Zhang J, Zhang Z, Miller W, Lipman DJ (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25:3389–3402
Anselmi N (1980) Studies on Drepanopeziza salicis (Tull.) v. Höhnel, perfect state of Gloeosporium salicis West. Eur J For Pathol 10:438–447
Banerjee D, Strobel GA, Booth E, Geary B, Sears J, Spakowicz D, Busse S (2010) An endophytic Myrothecium inundatum producing volatile organic compounds. Mycosphere 3:241–247
Castillo UF, Browne L, Strobel GA, Hess WM, Ezra S, Pacheco G, Ezra D (2007) Biologically active endophytic Streptomycetes from Nothofagus spp. and other plants in Patagonia. Microb Ecol 53:12–19
Cruz D, Suárez JP, Kottke I, Piepenbring M, Oberwinkler F (2011) Defining species in Tulasnella by correlating morphology and nrDNA ITS-5.8 S sequence data of basidiomata from a tropical Andean forest. Mycol Prog 10:229–238
Ezra D, Hess WM, Strobel GA (2004) New endophytic isolates of Muscodor albus, a volatile antibiotic producing fungus. Microbiology 150:4023–4031
Hanson JR (2005) The chemistry of the bio-control agent, Trichoderma harzianum. Sci Prog 88:237–248
Kudalkar P, Strobel GA, Riyaz-Ul-Hassan S, Geary B, Sears J (2011) Muscodor sutura, a novel endophytic fungus with volatile antibiotic activities. Mycoscience 53:319–325
Mitchell AM, Strobel GA, Moore E, Robison R, Sears J (2010) Volatile antimicrobials from Muscodor crispans. Microbiology 156:270–277
Parker SR, Cutler HG, Jacyno JM, Hill RA (1997) Biological activity of 6-pentyl-2H-pyran-2-one and its analogs. J Agric Food Chem 45:2774–2776
Rodrigues FFG, Costa JGM, Coutinho HDM (2009) Synergy effects of the antibiotics gentamicin and the essential oil of Croton zehnteri. Phytomedicine 16:1052–1055
Sharples RO (1959) Observations on the perfect state of Gloeosporium perennans in England. Trans Br Mycol Soc 42:507–512
Strobel GA (2006) Harnessing endophytes for industrial microbiology. Curr Opin Microbiol 9:240–244
Strobel GA, Daisy B (2003) Bioprospecting for microbial Endophytes and their natural products. Microbiol Mol Biol Rev 67:491–502
Strobel GA, Dirksie E, Sears J, Markworth C (2001) Volatile antimicrobials from Muscodor albus, a novel endophytic fungus. Microbiology 147:2943–2950
Strobel GA, Daisy B, Castillo U, Harper J (2004) Natural products from endophytic microorganisms. J Nat Prod 67:257–268
Strobel GA, Knighton B, Kluck K, Ren Y, Livinghouse T, Griffin M, Spakowicz D, Sears J (2008) The Production of Myco-diesel hydrocarbons and their derivatives by the endophytic fungus Gliocladium roseum. Microbiology 154:3319–3328
Strobel GA, Spang S, Kluck K, Hess WM, Sears J, Livinghouse T (2008) Synergism among volatile organic compounds resulting in increased antibiosis in Oidium sp. FEMS Microbiol Lett 283:140–145
Syhre M, Scotter JM, Chambers ST (2008) Investigation into the production of 2-Pentylfuran by Aspergillus fumigatus and other respiratory pathogens in vitro and human breath samples. Med Mycol 46:209–215
Tomsheck A, Strobel GA, Booth E, Geary B, Spakowicz D, Knighton B, Floerchinger C, Sears J (2010) Hypoxylon sp. an endophyte of Persea indica producing 1, 8 –cineole and other bioactive volatile with fuel potential. Microb Ecol 60:903–914
Veras HNH, Rodrigues FFG, Colares AV, Menezes IRA, Coutinho HDM, Botelho MA, Costa JGM (2012) Synergistic antibiotic activity of volatile compounds from the essential oil of Lippia sidoides and thymol. Fitoterapia 83:508–512
Verma VC, Kharwara RN, Strobel GA (2009) Chemical and functional diversity of natural Products from plant associated endophytic fungi. Nat Prod Commun 4:1–22
Wagner H, Ulrich-Merzenich G (2009) Synergy research: approaching a new generation of phytopharmaceuticals. Phytomedicine 16:97–110
White TJ, Bruns T, Lee SJWT, Taylor JW (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. PCR Methods Appl 18:315–322
Wilkinson HH, Siegel MR, Blankenship JD, Mallory AC, Bush LP, Schardl CL (2000) Contribution of fungal loline alkaloids to protection from aphids in a grass-endophyte mutualism. MPMI 13:1027–1033
Xie J, Strobel GA, Mends MT, Hilmer J, Nigg J, Geary B (2013) Collophora aceris, a novel antimycotic producing endophyte associated with douglas maple. Microb Ecol 66:784–795
Acknowledgments
The authors wish to acknowledge the financial support of the NSF via a grant to Dr. Brent Peyton of the MSU Department of Chemical and Biological Engineering and the DoE to Dr. Gary Strobel. George Schaible recognizes the Montana State University Undergraduate Scholars Program for its support. Technical and financial support was also provided from Endophytics LLC of 920 Technology Blvd. Suite 201, Bozeman, MT.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Schaible, G.A., Strobel, G.A., Mends, M.T. et al. Characterization of an Endophytic Gloeosporium sp. and Its Novel Bioactivity with “Synergistans”. Microb Ecol 70, 41–50 (2015). https://doi.org/10.1007/s00248-014-0542-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00248-014-0542-y