Research on decomposition and removal method of lignin for environment preservation by utilizing microorganisms

Lignin is an aromatic high molecular compound which takes 20-35% of wood compositions, and as the organic substances existing on the earth, it is second in abundance next to cellulose. When synthesized products, feeds, paper and others are produced from woods, it is indispensable to develop the technology for removing lignin that saves energy. In particular in paper and pulp industry, the formation of organic chlorine compound and dioxin has become environmental problem. The development of the effective methods of decomposing and removing lignin utilizing microorganisms and enzymes has been hastened. In this research, the structure of lignin which causes environmental pollution and its decomposition were elucidated and the creation of lignin-decomposing bacteria by γ ray irradiation and gene recombination was attempted. The separation and refining of the enzyme which is related to methoxyl removal reaction were continued. The testing methods and the results of the investigation of the course of lignin biosynthesis and the formation of mutant stocks by γ ray irradiation are reported. (K.I.)