Organic WastesThere are many sources of organic wastes on which fungi grow. Large quantity of ceulosic and lignocellulosic materials are present in agriculture, forestry an industry wastes. Trichoderma reesei, T.viride and T. harzianum have cellulase secreting ability which catalyze the conversion of cellulose to cellubiose, and cellubiose, in turn to glucose (Mandels and Stenberg, 1976). Before microbial invasion, cellulosic materials are treated with alkali so that, glucosidic bonds could be broken. Thus alkali treatment and hydrolysis of cellulosic material increases the biodegradability of cellulose by many fungi, for example, A.fumigatus, Chaetomium sp., Geotrichium candidwn, Penicillium sp. and Trichoderma sp.
The waste pods or carob beans contains sugars which are used as substrate for the growth of fungi e.g. A. niger, Fusarium moniliforme etc. Tate and Lyle Limited, U.K. has developed a process for utilization of carbohydrates in carob bean extracted by A. niger. A yield of 0.45 g/ g substrate of A. niger grown on carob bean extract was obtained (Litchfield, 1979).
The pellets of fungal mat are recovered from the growth medium by decantation and filtration process. For example, mycelial biomass of A. niger, which does not form pellets was separated by rotary vacuum filters. The mycelial biomass was dried in tray or belt driers.