Chemical and biochemical degradation of waste cellulosic materials

Some of the agricultural wastes such as, pith bagasse, rice husk and corn maize are subjected to both chemical and biochemical degradation. Different acid concentrations as well as cellulase-producing microorganisms are tested. Comparative studies between the chemical hydrolysis and enzymatic degradation, for the selected cellulosic materials, are discussed. Cellulase(s) enzyme activity, 50.25 mug/mL is obtained (pH 5.5 using 2g/L carbon source) in shaking culture. Results indicate that the optimum conc. of HCl, which gives the highest yield of reducing sugars from the used cellulose materials is 5 per cent. Byproducts formed by acid degradation and enzymatic hydrolysis reveal that the residue of chemical. hydrolysis is the most appropriate substrate for enzyme degradation rather than the raw materials. Screening of cellulase producing-organisms in the soil, show that actinomycetes and fungi are predominant. The most efficient fungal isolate is identified as Aspergillus ochraceous. Occurrence of free reducing sugars in the growth medium as well as prolonged incubation times, both drastically affect cellulase(s) yield. Reduction in sugar content and cellulose remaining are inversely proportional.