The study was conducted for the production of cellulase enzyme through liquid state bioconversion of palm oil mill effluent (POME) by filamentous fungi and characterization of the produced enzyme. Several experiments such as selection of filamentous fungi, optimization of media and process parameters, development of the separation/purification conditions for ultra-filtration, characterization and evaluation of purified cellulase enzyme through hydrolysis of oil palm empty fruit bunches (EFB) were carried out to achieve the entire objectives of the study. The results on isolation indicated...