Chapter 10 - Utilization of endophytic fungi for their volatile organic compounds as mycodiesel

Abstract

Presently, there is an immediate demand for alternative sources of fuel as the world’s reservoirs of fossils fuels are emptying. Lately, it has been found that fungi like Gliocladium sp., Ascocoryne sarcodies, Hypoxylon sp, and Phoma produce mixtures of gaseous carbon-based compounds that have fuel potential. These fungal derivatives have been dubbed mycodiesel. These products are also categorized as volatile organic compounds (VOCs). Researchers have identified and recorded nearly 250 fungal VOCs, many of which are known for their distinct odors and are biosynthesized during metabolism. Many endophytic fungi have been investigated for their biofuel production. Under microaerophilic growth environments, Nodulisporium sp. synthesized a number of VOCs, mainly alkyl alcohols like 1-propanol-2-methyl, 1-hexanol, 1-butanol-3-methyl, 1-pentanol, 1-heptanol, 1-nonanol, 1-octanol, and phenyl ethyl alcohol. The organism also generated a few terpenoids, secondary alcohols, alkyl esters, alkyl ketones, some benzene derivatives, and few neutral compounds like hydrocarbons. The majority of these products have potential to be used as fuel. These VOCs were captured by Carbotrap technology. These volatiles were then analyzed by fiber-GC/MS equipped with a headspace solid-phase micro extractor. An example of such investigation is the isolation of Myrothecium inunduatum from its host herb, Acalypha indica, which is a euphorbeacen herb from North-East India. In microaerophilic conditions, it produced methylcyclohexadiene, 1-methyl- and 1-ethyl propyl cyclohexane, and many other compounds having lots of fuel value. Nuclear magnetic resonance (NMR) spectroscopy was used to quantify VOC generation. This chapter presents a compilation of such VOCs along with a discussion on the endophytic fungi from which these are isolated. It also reviews the methods of their extraction and techniques of their identification.