ABSTRACT. A total of 15 strains were isolated and screened for beta-mannanase production at temperatures of 30, 45, and 65 °C in solid state fermentation using palm kernel cake (PKC) as substrate. The operating conditions were 20 % of inoculum, 110 % moisture content, pH 7.0, and PKC particle size 0.85 mm. At different temperatures, the highest beta-mannanase producers were identified: at 30 °C, isolate TW1 with 339.96 U/g dry PKC at 120 h; at 45 °C, isolate S51 with 73.03 U/g dry PKC at 12 h; at 65 °C, isolate GJ1-2 with 7.63 U/g dry PKC at 72 h. Isolate TW1 appeared to produce the highest enzyme activity when compared relatively with the other strains, and was selected for further investigation.
KEYWORDS: Beta-mannanase, palm kernel cake, screening, solid state fermentation