The biological detoxification of hazardous waste is largely an underdeveloped technology. Bacterial species are known to possess a variety of detoxification skills, apparently associated with the need to survive. Single bacterial species may not have the ability to convert a toxicant to carbon dioxide and water. With the use of bacterial communities, there is the feature that each species of the consortium plays a role in the overall degradation of the waste with the inadequacies of one covered by the abilities of another. The stability of such consortia is of some concern since there may be environmental effects that permit the selection of certain members over others resulting in the loss or slowing of the degradation process. The use of fungi to degrade waste materials has not been investigated to any extent until recently. From the perspective of sewage treatment, filamentous fungi were to be avoided due to processing problems and in some cases fungi found in sewage can be pathogenic.