Abstract:

This paper reports the optimization of the fermentation conditions for cellulase production by Penicillium
spinulosum 16-7 by Plackett-Burman design and response surface methodology using the statistical software Minitab.
By using Plackett-Burman design, carbon source (a combination of rice straw and wheat bran at a mass ratio of 7:3)
concentration, culture temperature and time were identified as main factors that influence cellulase production. The
selected variables were further investigated by steepest ascent analysis and optimized by response surface analysis.
The highest cellulase activity was obtained after culture at 27.11 ℃ for 146.27 h at a carbon source concentration of
3.45 g/100 mL, leading to a predicted filter paper activity of 132.53 U/mL. Under the modified fermentation conditions of
3.45 g/100 mL carbon source concentration, 27 ℃ and 146 h, carboxymethyl cellulase activity was 387.58 U/mL and the
filter paper activity was 128.86 U/mL, 49.07% higher than that obtained before optimization.

Key words: cellulase enzyme, fermentation, Plackett-Bumann design, response surface analysis, Penicillium spinulosum