Biodegradation of some agricultural residues by fungi in agitated submerged cultures

Abstract

Digestibility of agricultural residues in animal feeding is deeply dependent on the amounts and types of
their fibers. Biological treatment of agricultural residues is a new method for improvement of
digestibility. Therefore, the capacity of a few fungi in biodegradation of some agricultural residues was
studied. Losses of crude fiber (CF), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of
wheat, barley, rice, wood, and pea straw were investigated in agitated submerged culture during
biodegradation by fungi. Biodegradation of the plant residues is dependent on the plant and fungus
species. The biodegradation order of plant residues was pea>barley>wheat>rice>wood. A. terreus and T.
reesei were more able to degrade the easy degradable plant residues. Rice and wood were degraded
more by Armillaria sp., Polyporus sp. and P. chrysosporium. Crude fiber, NDF and ADF of agricultural
residues were reduced more by P. chrysosporium. Generally, the reduction of agricultural residues NDF
by fungi was more than their ADF. However, Polyporus sp. decreased ADF of wheat straw more. Thus,
for improvement of digestibility of agricultural residues, the treatment by white-rot fungi may be
recommended.