Abstract: A process for producing deacetylase which comprises incubating a deacetylase-producing bacterium belonging to Vibrio cholerae in a IFO 15429 culture medium containing a carbon source, a nitrogen source, an inorganic salt and an inducer for producing the deacetylase and isolating the deacetylase from cells separated from said culture medium.

Abstract: A process for preparing a low-molecular weight chitosan which comprises adding chitosan to water containing a monobasic acid to prepare an intimate chitosan-water mixture and treating said mixture with cellulase.

Abstract: A cellulosic material is saccharified by cellulases and the resulting saccharified solution is acidified. Subsequently chitosan and/or partially deacetylated chitin are dissolved therein and the obtained solution is alkalified. Thus the cellulases are absorbed by the chitosan and/or partially deacetylated chitin. Further a cellulosic material is saccharified by at least one cellulase originating from a fungus belonging to the genus Aspergillus and at least either chitosan and/or partially deacetylated chitin are added to the resulting saccharified solution to thereby adsorb the cellulase by the chitosan and/or partially deacetylated chitin.

Abstract: A process for the saccharification of celluloses is provided. More particularly, a solution obtained after the degradative saccharification of cellulosic materials with cellulases is separated into a liquid portion containing saccharides and a solid matter. Cellulases are recovered from said liquid portion containing saccharides, while said solid matter is treated with an aqueous pH-buffered solution, or an aqueous solution, alcoholic aqueous solution or aqueous pH-buffered solution of polysaccharides or oligosaccharides, or aqueous or aqueous pH-buffered solution of alcohols to recover the cellulases in the solid matter. With the use of this solid matter, newly added cellulosic materials are degradatively saccharified in an aqueous solution or the above-mentioned solutions.