CHARACTERIZATION AND LIGNIN DEGRADATION PROPERTIES OF THE LIGNINOLYTIC ENZYMES IN THE EXTRACELLULAR FLUIDS OF PHANEROCHAETE CHRYSOSPORIUM 1038

The effect of ligninolytic enzymes in the extracellular fluids of the cultivated cells of basidiomycetic fungi of Phanerochaete chrysosporium strain 1038 on hydrolyzed lignin samples in vitro was investigated. The growth conditions of the strain were optimized in regard to receive higher activities of ligninolytic enzymes. The influence of inorganic nitrogen, Mn2+ ions, temperature and pH of the medium on the growth and enzymes activity was also studied. It was found that extracellular fluids of the cultivated strain showed activities of lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase (Lac). The addition of 2.2 mM nitrogen and 3.5 mg/L Mn2+ to the medium kept constantly at 37 degrees C and pH = 5 increased significantly the quantity of exuded by cells soluble protein with considerable activities of LiP, MnP and Lac. The extracellular fluids, concentrated by ultrafiltration were incubated for 24 h with samples of hydrolysis lignin. Evidence for the delignification processes was provided by FTIR spectroscopy, which showed decrease of free carboxylic and increase of hydroxylated and methoxylated aliphatic groups in the treated samples. The changes were regarded as result of oxygenation processes caused by the extracellular ligninolytic enzymes.