Hypoxylon sp., an Endophyte of Persea indica, Producing 1,8-Cineole and Other Bioactive Volatiles with Fuel Potential

Abstract

An endophytic fungus of Persea indica was identified, on the basis of its anamorphic stage, as Nodulosporium sp. by SEM. Partial sequence analysis of ITS rDNA revealed the identity of the teleomorphic stage of the fungus as Hypoxylon sp. It produces an impressive spectrum of volatile organic compounds (VOCs), most notably 1,8-cineole, 1-methyl-1,4-cyclohexadiene, and tentatively identified (+)-.alpha.-methylene-.alpha.-fenchocamphorone, among many others, most of which are unidentified. Six-day-old cultures of Hypoxylon sp. displayed maximal VOC-antimicrobial activity against Botrytis cinerea, Phytophthora cinnamomi, Cercospora beticola, and Sclerotinia sclerotiorum suggesting that the VOCs may play some role in the biology of the fungus and its survival in its host plant. Media containing starch- or sugar-related substrates best supported VOC production by the fungus. Direct on-line quantification of VOCs was measured by proton transfer mass spectrometry covering a continuous range with optimum VOC production occurred at 6 days at 145 ppmv with a rate of production of 7.65 ppmv/h. This report unequivocally demonstrates that 1,8-cineole (a monoterpene) is produced by a microorganism, which represents a novel and important source of this compound. This monoterpene is an octane derivative and has potential use as a fuel additive as do the other VOCs of this organism. Thus, fungal sourcing of this compound and other VOCs as produced by Hypoxylon sp. greatly expands their potential applications in medicine, industry, and energy production.

The Production of 1,8-Cineole, a Potential Biofuel, from an Endophytic Strain of <i>Annulohypoxylon</i> sp. FPYF3050 When Grown on Agricultural Residues

“…However, starch, glucose, and cellobiose as a source of carbohydrates, were reported to facilitate higher concentrations of 1,8-cineole of Hypoxylon sp. CI4A [9]. Therefore, the Annulohypoxylon sp.…”

Functionalized para-substituted benzenes as 1,8-cineole production modulators in an endophytic Nodulisporium species

“…Initial isolation of the fungus followed the procedures of Tomsheck et al (2010). In summary, plant samples were surface sterilized by exposure to 70 % ethanol, and placed on water agar and glycerol arginine medium.…”

“…The ITS region was amplified by PCR using the universal ITS primers ITS1 (59-TCCGTAGGTGAACCTGCGG-39) and ITS4 (59-TCCTCCGCTTA-TTGATATGC-39). The primer pair, the PCR and DNA sequencing were all carried out as described by Tomsheck et al (2010). The amplified products were sequenced and aligned with sequences in GenBank by the BLASTN program (Altschul et al, 1997).…”

“…In 2010, an endophytic Hypoxylon species was identified as the first non-plant source of 1,8-cineole, a monoterpene with fuel potential (Tomsheck et al, 2010). Since then many other isolates of Nodulisporium sp., the imperfect stage of this organism, have been isolated and shown to produce cineole (Strobel, 2014).…”

“…For cineole to be implemented as a biofuel, more efficient and higher yielding methods for its production must be developed (Gladden, 2013;Tomsheck et al, 2010). Presently, the only industrial-scale cineole collection method involves a relatively inefficient distillation of crude eucalyptus oil obtained from plant materials (Babu & Singh, 2009).…”