COMPOSITIONAL CHANGES IN COMPOST DURING COMPOSTING AND GROWTH OF AGARICUS-BISPORUS

Samples from conventional compost taken at various stages of compostin g and mushroom (Agaricus bisporus) growth were analyzed for changes in 80% ethanol and water extracts, monosaccharides in acid hydrolysates of polysaccharides, lignin concentration, and lignin structural featur es. Variable amounts of extraneous inorganic solids in the form of fin e sandy particles were removed by sedimentation of the samples in a ca rbon tetrachloride-dibromomethane mixture. During composting, about tw o-thirds of the initial wall polysaccharides were consumed by compost microorganisms, and only 17% of the total polysaccharides were used du ring mushroom production. The relative lignin content of composts as m easured by the acetyl bromide procedure increased, both during compost ing and mushroom growth, and the chemical structure of lignin was alte red by condensation and oxidation reactions.