Physical parameter optimization of cellulase production by Aspergillus niger on solid-state fermentation of cassava waste
Abstract
Cellulases are a group of hydrolytic enzymes and are capable of degrading
lignocellulosic materials contain carbohydrate polymers such as cellulose, hemicelulose
and starch. Cellulases have wide range of applications. In this study, cellulase
production was carried out in solid-state fermentation using cassava waste as a substrate
by using Aspergillus niger. Different fermentation conditions were examined to assess
their effect in optimizing enzyme production. The effects of various process variables
were studied for optimum production of cellulase enzyme using cassava waste including
moisture content (%), fermentation time (day) and inoculums size (ml). Fermentation of
A.niger with cassava waste substrate will produce cellulases. Cellulases enzyme will
degrade cellulose to the smaller glucose units. The production of cellulase was
determined based on glucose concentration. Full factorial composite experimental
design and central composite design (CCD) were used in the design of experiments and
analysis of results. The result indicated that the optimal condition for fermentation of 5 g
cassava waste substrate by A.niger was obtained at 100 % of moisture content, 7.95 days
of fermentation and 3.78 ml of inoculums size. The coefficient of determination
obtained was 0.9125 shows the model adequacy was very satisfactory.