| Summary: | Global warming resulted from CO2 level increase in the atmosphere has
caused elevation of earth temperature and uncertain climate changes. CO2 is
mainly emited from industrial activities and vehicles combustion. To prevent the
rise of CO2 in the atmosphere can be done by using biomass fuel such as
bioethanol. Using bioethanol can make the carbon cycle close, so the total of CO2
in the atmosphere will remain the same (amount of CO2 on the atmosphere can
warm the earth temperature).
The raw materials of bioethanol can be derived from oil palm empty fruit
bunch. In the whole process of bioethanol production, hydrolysis of cellulose to
glucose is the most important stage. Cellulose hydrolysis can be carried out
chemically or enzymatically. Enzymatic hydrolysis utilizes cellulase-producing
fungus and in this research, Aspergillus niger was chosen. The glucose produced is
consumed by A niger as carbon source and this is undesirable, therefore it should
be minimized as low as possible. Knowing the rate of glucose consumption is
important to have the optimum design of enzymatic hydrolysis of cellulose.
This study aimed to determine the rate of glucose consumption by A. niger on
cellulose hydrolysis process. The rate of glucose consumption is influenced by the
growth rate of A. niger, and, in turn, the fungus growth rate is influenced by the
concentration of glucose and citric acid (a metabolic product of energy from A.
niger). Kinetics of glucose consumption by A. niger was studied in batch system
with variation of initial glucose concentration of 30, 50, 70 g/l. The greater initial
concentration of glucose would result higher consumption rate of glucose and citric
acid production, but the A. niger growth rate was relatively same. The growth rate
of A. niger, the rate of glucose consumption, and the rate of formation of citric acid
were 0.0497 g/l.h, 0.0443 g/l.h, 0.0486 g/l.h
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