Research Article Cellulase and Xylanase Production by Penicillium echinulatum in Submerged Media Containing Cellulose Amended with Sorbitol

Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The present work investigated the use of sorbitol as a soluble carbon source, in association with cellulose, to produce cellulases and xylanases in submerged cultures of Penicillium echinulatum 9A02S1. Because cellulose is an insoluble carbon source, in cellulase production, there are some problemswith rheology and oxygen transfer.The submerged fermentations containingmedia composed of 0, 0.25, 0.5, 0.75, and 1 % (w/v) sorbitol and cellulose that were added at different times during the cultivation; 0.2 % (w/v) soy bran; 0.1 % (w/v) wheat bran; and a solution of salts. The highest filter paper activity (FPA) (1.95 ± 0.04 IU⋅mL−1) was obtained on the seventh day in the medium containing 0.5 % (w/v) sorbitol and 0.5 % (w/v) cellulose added 24 h after the start of cultivation. However, the CMCases showed an activity peak on the sixth day (9.99 ± 0.75 IU⋅mL−1) in the medium containing 0.75 % (w/v) sorbitol and 0.75 % (w/v) cellulose added after 12 h of cultivation. The xylanases showed the highest activity in the medium with 0.75 % (w/v) sorbitol and 0.25 % (w/v) cellulose added 36 h after the start of cultivation. This strategy enables the reduction of the cellulose concentration, which in high concentrations can cause rheological and oxygen transfer problems. 1