In vitro degradation of wheat and paddy straw substrates by thermophilic fungi isolated from Agaricus bisporus compost

Abstract

Time course decomposition of wheat straw and wheat + paddy straw (1:2) by the three most prevalent thermophilic fungi viz., Scytalidium thermophilum, Humicola grisea and H. insolens was studied in seven combinations under in vitro conditions in flasks at 50±1°C for 21 days at weekly intervals. The per cent variation on equal ash basis in various constituents of wheat straw and wheat + paddy straw (1:2) mixture indicated a progressive decrease from 7 to 21 days with all the cultures. A maximum reduction of 62.88-55.67, 44.50-39.61, 68.73-60.70, and 86.61-76.19% in wheat straw and 65.50-60.71, 50.68-44.20, 74.14-66.53 and 94.35-89.86% in wheat + paddy straw (1:2) mixture for neutral detergent fibre, acid detergent fibre, cellulose and hemicellulose respectively, was observed with different cultures. The lignin content was found to increase after 21 days. Reduction of the various fibre fractions was more with mixed cultures as compared to mono cultures with comparatively better utilization of the various constituents in wheat + paddy straw mixture as compared to wheat straw alone.