Isolation and selection of cellulolytic fungi from palm oil mill effluent

Cellulolytic fungi, 34 strains, were isolated from samples taken from palm oil mill residues and effluent, and high cellulase producers selected in comparison with nine known reference strains. Although 13 isolates showed good filter paper distintegration within 14 days, only eight isolates exhibited clearing zones around their colonies on carboxymethylcellulose (CMC) agar medium. Quantitative cellulase activity measurements, using CMC as carbon source, selected three of the eight isolates as potential cellulase producers. Using dried palm oil mill condensate as carbon source, only one of the isolates (F 11) showed similar results on both carbon sources. During media optimization for CMCase production, a four-fold increase from 0.058 to 0.275 U/ml was obtained using a medium, containing 0.1% (v/v) Tween 80 0.02% (w/v) NH4NO3, 0.025% (w/v) proteose-peptone and 0.1% (w/v) CMC dissolved in undiluted condensate from the sterilization of oil palm bunches, with an initial pH of 5.5.