ABSTRACT
The Pol6 mutant of Penicillium occitanis, secreting a large quantity of cellulases, was cultivated in fermentor using a local paper pulp as an inducer substrate. A high titer of extracellular cellulase activity was reached after a fed batch process: 23 IU x ml(-1) filter paper activity, 21 IU x ml(-1) CMCases activity (endoglucanase units) and 25 mg x ml(-1) of proteins. Various tests were done to compare the action of the P. occitanis cellulases with those commercially available and with the traditional stonewashing process. This cellulase preparation was successfully applied in a biostoning process at an industrial scale. The abrasive effect of the P. occitanis cellulases was very uniform and with an efficiency comparable to that obtained by the commercial ones.
Subject(s)
Cellulase/chemistry , Penicillium/enzymology , TextilesABSTRACT
The stabilization of fungal cellulases by spray drying, the thermal stability of Penicillium occitanis cellulases and the effect of some additives were studied. We observed that CMCase activity presents a good stability at 50 degrees C, even after 60 h of incubation. On the other hand, beta-glucosidase activity was more sensitive (loss of 50%) and reacts on total cellulases activities (Filter paper activities). The addition of hydrophilic agents such as ethylene glycol, polyethylene glycol (PEG6000) enhanced enzyme activity. The effect of PEG and Maltodextrin, another water activity decreasing agent, were then tested during the spray drying of Pol6 cellulases. The presence of 1% PEG allowed the best recovery but had a negative effect on enzyme stability while 1% Maltodextrin showed a negative effect on enzyme recovery but a very positive effect on enzyme stabilization.
