An economic process for the enzymatic hydrolysis of cellulose would allow utilization
of cellulosic biomass for the production of easily fermentable low-cost sugars. New
and more efficient fermentation processes are emerging to convert this biologic currency
to a variety of commodity products with a special emphasis on fuel ethanol production.
Since the cost of cellulase production currently accounts for a large fraction of
the estimated total production costs of bioethanol, a significantly less expensive
process for cellulase enzyme
production is needed. It will most likely be desirable to obtain cellulase production
on different carbon sources-including both polymeric carbohydrates and monosaccharides.
The relation between enzyme production and growth profile of the microorganism is
key for designing such processes. We conducted a careful characterization of growth
and cellulase production by the soft-rot fungus Trichoderma reesei. Glucose-grown
cultures of T. reesei Rut-C30 were subjected to pulse additions of Solka-floc (delignified
pine pulp), and the response was monitored in terms of CO2 evolution and increased
There was an immediate and unexpectedly strong CO2 evolution at the point of Solka-floc
addition. The time profiles of induction of cellulase activity, cellulose degradation,
and CO2 evolution are analyzed and discussed herein.