Lignin in woody tissues after chemical pretreatment and bacterial attack

Summary Tangential latewood sections (60 m) of Scots pine sapwood were differently treated with chlorite. The subsequently incubated two strains of Bacillus polymyxa caused a weight loss up to about 25%, including a loss of lignin of about 42%.UV-microspectrophotometry of 1 m-cross-sections prepared from the cultured woody tissues demonstrated that bacteria caused neither quantitative nor qualitative changes of the remaining lignin.The lignin, which was dissociated from the pretreated woody cell wall by bacteria, could not be respired, suggesting that the lignin is a ballast to these bacteria that inhibits the dissimilation of the carbohydrates in the wood.We appreciate the financial support by Deutsche Forschungsgemeinschaft. Thanks are due to Mrs. R. Endeward for her assistance during the microspectrophotometric evaluations and to Mr. U. Engel and Dr. O. Faix for carrying out the IR-measurements