Bioconversion of Straw into Improved Fodder: Fungal Flora Decomposing Rice Straw

The fungal flora decomposing rice straw were investigated all over the soil of Sharkia Province, east of Nile Delta, Egypt, using the nylon net bag technique. Sixty-four straw-decomposing species belonging to 30 genera were isolated by the dilution plate method in ground rice straw-Czapek's agar medium at pH 6. The plates were incubated separately at 5℃, 25℃ and 45℃, respectively. Twenty nine species belonging to 14 genera were isolated at 5℃. The most frequent genus was Penicillium (seven species), and the next frequent genera were Acremonium (three species), Fusarium (three species), Alternaria, Chaetomium, Cladosporium, Mucor, Stachybotrys (two species) and Rhizopus stolonifer. At 25℃, 47 species belonging to 24 genera were isolated. The most frequent genus was Aspergillus (nine species), and the next frequent genera were ranked by Penicillium (five species), Chaetomium (three species), Fusarium (three species). Each of Alternaria, Cladosporium, Mucor, Myrothecium and Trichoderma was represented by two species. At 45℃, 15 species belonging to seven genera were isolated. These were seven species of Aspergillus, two species of Chaetomium and two species of Emericella, while Humicola, Malbranchea, Rhizomucor and Talaromyces were represented by one species respectively. The total counts of fungi the genera, and species per gram of dry straw were significantly affected by incubation temperature and soil analysis (P < 0.05).