Cellulase production by Penicillium funiculosum and its application in the
hydrolysis of sugar cane bagasse for second generation ethanol
production by fed batch operation
This study aimed to produce a cellulase blend and to evaluate its application in a simultaneous saccharification
and fermentation (SSF) process for second generation ethanol production from sugar cane bagasse.
The sugar cane bagasse was subjected to pretreatments (diluted acid and alkaline), as for disorganizing
the ligocellulosic complex, and making the cellulose component more amenable to enzymatic hydrolysis.
The residual solid fraction was named sugar cane bagasse partially delignified cellulignin (PDC), and
was used for enzyme production and ethanol fermentation. The enzyme production was performed in a
bioreactor with two inoculum concentrations (5 and 10% v/v). The fermentation inoculated with higher
inoculum size reduced the time for maximum enzyme production (from 72 to 48). The enzyme extract
was concentrated using tangential ultrafiltration in hollow fiber membranes, and the produced cellulase
blend was evaluated for its stability at 37 ◦C, operation temperature of the simultaneous SSF process, and
at 50 ◦C, optimum temperature of cellulase blend activity. The cellulolytic preparation was stable for at
least 300 h at both 37 ◦C and 50 ◦C. The ethanol production was carried out by PDC fed-batch SSF process,
using the onsite cellulase blend. The feeding strategy circumvented the classic problems of diffusion
limitations by diminishing the presence of a high solid:liquid ratio at any time, resulting in high ethanol
concentration at the end of the process (100 g/L), which corresponded to a fermentation efficiency of 78%
of the maximum obtainable theoretically. The experimental results led to the ratio of 380 L of ethanol
per ton of sugar cane bagasse PDC.