STUDIES ON THE MICROBIAL-DEGRADATION OF A NIGERIAN PREOXIDIZED SUBBITUMINOUS COAL

The potential for coal degradation was studied in a strain of Phanerochaete chrysosporium which showed fast growth and highest coal degradation amongst several basidiomycetes tested. The organism was grown under submerged culture conditions using an alkali-solubilized precipitate of subbituminous coal as fermentation substrate. The biodegradation produced a water-soluble, acid-precipitable intermediate product that yielded a recovery rate of 32%. Non-inoculated controls yielded little acid-precipitable polymers, but supernatant solutions from inoculated cultures produced quantities of coal polymers that correlated with the biodegradability of the coal. The molecular weight of the bioproduct was estimated to be around 3.2 x 10(4). Elemental analysis gave the following composition; C, 47.04%; H, 4.99%; O, 42.69%; N, 4-65% and S, 0.75%, corresponding to the simplest molecular formula, C100 H126.4 O90.7 N8.5 S0.60. Biological treatment caused an increase in the content of metallic elements of the coal substrate.