Several fungi from fire-prone forests of southern India can utilize furaldehydes

Abstract

Furfural and 5-hydroxymethylfurfural (HMF), released during thermo-chemical degradation of lignocellulosic biomass, inhibit microbial fermentation of sugars to biofuels. One approach to circumvent this roadblock is through microbial degradation of furaldehydes in biomass hydrolysates. Since these furaldehydes are the most common and abundant volatile organic compounds in plant litter and are released during biomass burning, we investigated endophytic and litter fungi of fire-prone forests for their ability to utilize furaldehydes. Of the 23 (11 endophytic and 12 litter) fungi we tested, 10 grew on furfural, 21 on HMF, and nine on both substrates as the sole carbon source. These fungi initially grew slower on furaldehydes than on sucrose, but their growth increased on subsequent sub-culturing on the same furaldehyde medium, suggesting an innate-adaptation competence. The ability of endophytic and litter fungi of fire-prone forests to metabolize furaldehydes is more common than previously anticipated and helps rationalize their unusual ecological fitness in specific niches. Our findings should also motivate a closer examination of all locales of biomass (including crop residue) burning for identifying furaldehyde-utilizing fungi.