Methods for isolating EG III cellulase component and EG III cellulase in polyethylene glycol using inorganic salt and polyethylene glycol

A method for isolating EG III cellulase component substantially free of other cellulase proteins from an aqueous mixture containing cellulase proteins which method comprises

• i- adding an inorganic salt and polyethylene glycol having a molecular weight of from about 5,000 to 10,000 to the aqueous mixture of cellulase proteins under conditions to create a two-phase system wherein substantially all of the cellulase proteins, other than EG III, are retained in an EG III-poor aqueous phase and the EG III cellulase component is retained in an EG III-rich polyethylene glycol phase,
• ii- separating the polyethylene glycol, EG III-rich phase from the aqueous, EG-III poor phase and collecting said EG III-rich polyethylene glycol phase that is substantially free of other cellulase proteins in said aqueous mixture and
• iii- separating the EG III from the polyethylene glycol EG III-rich phase and collecting the EG III component.