Plant Waste Hydrolysis by Extracellular Enzymes of Aspergillus niger and Penicillium chrysogenum: Effect of Ammonia Pretreatment

Abstract

Aspergillus niger (ANL301) and Penicillium chrysogenum (PCL 501) cultured in basal media with cellulose as sole
carbon source yielded extracellular enzymes which partially hydrolyzed sawdust and sugarcane pulp into simple
sugars. Pre-treatment of sawdust by ammonium hydroxide steeping increased the yield of simple sugars. The reducing
sugars released from the pretreated sawdust by the crude enzymes of A. niger (ANL301) and P. chrysogenum
(PCL 501) were 3.58% and 7.02% of the total hydrolysable sugars respectively. This is in contrast to the 0.92% and
1.02% of the total hydrolysable sugars released respectively by the enzymes of A. niger (ANL301) and P. chrysogenum
(PCL 501) from the non-pretreated sawdust. Enzymatic hydrolysis of sugarcane pulp by the crude enzymes
was not significantly affected by ammonia pre-treatment. Reducing sugars released from non-pretreated sugarcane
pulp by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were respectively 4.17% and
5.08% of the total hydrolysable sugars.