INFLUENCE OF NUTRIENT AMENDMENT ON THE BIODEGRADATION OF WHEAT-STRAW DURING SOLID-STATE FERMENTATION WITH TRAMETES-VERSICOLOR

The present study proposes a system whereby lignin biodegradation in l ignocellulosic units may be optimised with the minimum loss of cellulo se and other organic matter. Lignin, cellulose and organic matter loss es were followed at 7-day intervals during 35-day solid state fermenta tion of wheat straw with Trametes versicolor with and without amendmen t carbon (C) and nitrogen (N) sources. Substrate supplementation with a C source favoured degradation of lignin; glucose as the C source was better than beet pulp molasses. Ammonium N slowed lignin removal. Lig nin loss during 35-day fermentation in the presence of glucose was 42% as compared with 17.1% in the unamended wheat straw. The highest rati os of lignin loss to cellulose loss (9.55:1) and to organic matter los s (3.34:1) occurred in the first 14 days of fermentation when the stra w was amended with glucose. These observations indicate that for effic ient ligninolysis, it is appropriate to terminate fermentation of the glucose-amended straw at the 14-day stage at which 36.3% lignin degrad ation occurred at the cost of only 3.8% cellulose and 10.7% organic ma tter. Copyright (C) Published by 1996 Elsevier Science Limited.