During the process of alcoholic fermentation (ethanol production), it is common to happen contaminations in the fermentative way, caused by bacteria and/or wild yeasts. One of the main contaminations consequences is the yeasts flocculation phenomenon, which is reflected directly on the difficulty of sugar conversion in ethanol, tubulation blockage, ferment loss in the centrifuge and increase of expenses with inputs. These problems, besides they bring operational difficulties, they also have economical implications. The flocculation can be solved through a treatment with enzymes (proteases), which act directly on the yeast cellular wall, substituting the conventional treatment (using a constant flow of sulfuric acid). The enzymes immobilization on solid supports allows, besides their catalytic activity reuse, a better control of the reactions and they can be easily incorporate in a continuous process line. The chitin is the second more abundant polysaccharide in the nature and it is relatively cheap. The present work has as objective, through the crosslinking technique, the papain immobilization on chitin and subsequently its use as alternative at flocculation treatment.
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