Degradation of Agricultural Wastes by Freshwater Fungi and Its Application as Bioresources

Climate change caused by global warming has become the most serious environmental problem for human beings. Therefore, human beings have developed many technologies and resource management methods to reduce global warming. Resource replacement from oil resource to biological resource is one of the most useful option to overcome global warming by reducing carbon emission. In recent years, various technologies were developed for application of biological resource such as crops or residues. However, application of agricultural wastes as biological resource is still challenging because of its strong and complex structures. At this point, fungi can be some useful tools for application of agricultural wastes as bioresources because fungi has various exocellular enzymes to degrade complex organic materials. We tried to find useful freshwater fungi which applicable for biological conversion of agricultural wastes. One hundred freshwater fungal strains including white rot fungi, unrecorded fungal species were selected for lignocellulose degrading enzyme activity test. We selected 9 other freshwater fungal strains which have organic acid producing ability for conversion test of degraded agricultural wastes to bioresources. After the experiment, 10 fungal strains were selected for degradation test of agricultural waste and 3 fungal strains were selected conversion test. By the experiment using real agricultural waste, we determined that Phanerochaete concrescens strain NNIBRFG37506 was the most suitable for degradation of agricultural wastes and Rhizopus oryzae strain NNIBRFG22567 was suitable for conversion of degraded agricultural wastes.