Production, function and neutralization of oxalic acid produced by the dry rot fungus and other brown rot fungi
The formation of oxalic acid by the wood-destroying fungi causing brown rot, is found to be the key which by hydrolysing the hemicellulose brings the cellulose in the tracheid wall in contact with the cellulase enzymes and yeld watersoluble sugars leaving only a lignin skeleton. To control the pH in the substrate the excess oxalic acid is precipitated to water insoluble calcium oxalate by the dry rot fungus in contact with a calcium source. As source glass can be used, however, mortar, concrete or clay soil is better. Heavy metals that form complex compounds with oxalic acid can substitute calcium certain to a degree. The wet rot fungus Coniophora putenea is not dependent on calcium like the dry rot fungus. By producing acetic as well as oxalic acid it might form a buffer solution which controls the pH in the substrate.
Keywords: SERPULA LACRYMANS; CONIOPHORA PUTEANA; RIGIDOPORUS VITREUS; pH; BROWN ROT; WHITE ROT; OXALIC ACID; ACETIC ACID; CALCIUM; HEAVY METALS; ENZYMES; FUNGI