Activity of ligninase peroxidase from Acinetobacter anitratus and the degradation of Pinus pinaster lignin

The ligninase activity of Acinetobacter anitratus cells and enzyme extracted from that bacterium was measured with a model substrate (benzyl alcohol) and two lignin substrates: Pinus pinaster lignin precipitated from kraft black liquor and treated black liquor. The activity of this intracellular enzyme was confirmed on benzyl alcohol, showing a sigmoid Michaelis curve for constant H₂O₂ concentration. Enzymatic activity on treated black liquor leads to the production of low molecular weight compounds and to partial polymerisation of lignin. The evolution of the molecular weight distribution of the original sample with time was followed by high pressure liquid chromatography.