RESUMO
Colonization and oxidative metabolism of South African low-rank discard coal by the fungal strain ECCN 84 previously isolated from a coal environment and identified as Neosartorya fischeri was investigated. Results show that waste coal supported fungal growth. Colonization of waste coal particles by N. fischeri ECCN 84 was associated with the formation of compact spherical pellets or sclerotia-like structures. Dissection of the pellets from liquid cultures revealed a nucleus of "engulfed" coal which when analyzed by energy dispersive X-ray spectroscopy showed a time-dependent decline in weight percentage of elemental carbon and an increase in elemental oxygen. Proliferation of peroxisomes in hyphae attached to coal particles and increased extracellular laccase activity occurred after addition of waste coal to cultures of N. fischeri ECCN 84. These results support a role for oxidative enzyme action in the biodegradation of coal and suggest that extracellular laccase is a key component in this process.
