PROCEDIMENTO PER IL REIMPIEGO DI UN ENZIMA

The endoglucanase (E.C. 3.2.1.4) (I) and cellobiohydrolase (E.C. 3.2.1.91) (II) portions of activity of cellulose enzyme (III) which has been used as the cellulose hydrolysing enzyme in a simultaneous saccharification-fermentation reaction of cellulose to EtOH are recycled as follows: (a) the liq. fraction (contg. (III) and EtOH) is sepd. from the reaction mixt. and treated with a cellulose-contg. solid (which is useful for the simultaneous saccharification-fermentation reaction) at pH 5-8 and at ionic strength >0.05M so that (III) are adsorbed on the solid; (b) the solid fraction contg. adsorbed enzymes is sepd.; and (c) the solid enzyme-cellulose combination is used as a portion of the feed to a further simultaneous saccharification-fermentation reaction. By recovering and re-using the (III) components (i.e. (I) and (II)) adsorbable on cellulose, the components are conserved, and the yield and rate of recovery of EtOH from a subsequent saccharification-fermentation reaction are increased.