The Biological Degradation of Lignin ' IV

Studies made in the field of microbiological degradation of lignin have included investigations with sodium and calcium lignosulfonates. Kazanskii and Mikhailova (1936) were unable to grow several wood-rotting fungi on neutralized waste sulfite liquor, but found that infusorial earth mixed cultures could grow albeit slowly (in 50-60 days) if several alterations were made in the composition of the waste sulfite liquor. Ledingham and Adams (1942) investigated Polyporus versicolor, other wood-rotting fungi, and several soil fungi for their ability to metabolize calcium lignosulfonate in a glucose-mineral salts medium. They reported substantial degradation of the calcium lignosulfonate when a beta-naphthylamine precipitation method of analysis was used, but much less evidence of degradation was found where an ultraviolet method was used (Adams and Ledingham, 1942). Their conclusions were based on the disappearance of the lignosulfonate from liquid cultures in which the fungi were growing. In previous papers it was reported by Pelczar et al (1950) and Gottlieb et al (1950), that the wood-rotting (white rot) fungus Polyporus versicolor could utilize native lignin to a limited degree as a sole source of carbon. It was the purpose of this investigation to determine whether this organism could utilize sodium lignosulfonate. Using a system of analyses for both mycelial substance and culture fluid it has been shown that although the lignosulfonate disappears from solution it can be accounted for in or on the mycelia.