7. A substantially purified and isolated protein fraction, obtained from a composition according to claim 2 , and having at least 50% of its maximal cellulase activity at a pH between about 6.0 and about 7.0.
7. A substantially purified and isolated protein fraction, obtained from a composition according to claim 2 , and having at least 50% of its maximal cellulase activity at a pH between about 6.0 and about 7.0. 13. A substantially purified and isolated neutral and/or alkaline cellulase enzyme, isolated from a protein fraction according to claim 7 , and having a pI of between about 3 and about 5.5.