Physicochemical characterization of cellulase produced from <i>Kurthia gibsonii</i> isolated from cassava dumpsites in Ibadan, Nigeria

Abstract

This experiment reports the physicochemical characterization of cellulase produced by Kurthia gibsonii CAC1 isolated from cassava dumpsites in Ibadan, Nigeria. Lineweaver-Burk plot of cellulase activities of K.gibsonii CAC1 was examined with K max and V max of the enzyme assayed. At optimal pH of 5.0, 10% increase in enzymatic activities was observed. The enzymatic activities of K. gibsonii CAC1 were optimal at 30 o C and were still stable at 60 o C with 50% reduction in cellulase activities. Cellulase activities of K. Gibsonii CAC1 showed significant difference (p≥0.05) with the different cations used. There was no significant difference (p≤0.05) observed with increased concentrations (p≤0.05) using two-way ANOVA. Ca 2+ highly enhanced the cellulase activities of K.gibsonii CAC1 by 60% at 10mM. Highest inhibition by Hg 2+ was observed at 20mM with 50% inhibition. At increasing concentration of the inhibitors, there was no significant difference (p≤0.05) in cellulase activities; although the effect of each inhibitor on the enzymatic activity was significantly different (p≥0.05). Benzoic acid gave the highest inhibition of the cellulase activities in K. gibsonii CAC1 by 30% at 20mM, while Ethylene diamine-tetraacetic acid (EDTA) boosted the enzymatic activities by 10% at 10mM. There was a significant difference (p≥0.05) in the effect of different surfactants on the enzymatic activity but no significant difference (p≤0.05) with the concentration of the surfactants on cellulase activity. Enzymatic activities of the bacterium were enhanced by Polyoxyethylenesorbitan mono-oleate (Tween 80) with a boost of 50%. Increasing the concentration of sodium dodecyl sulphate (SDS) and Polyethylene glycol pisooctylphenylether (Trition X-100) caused a 70% increase in cellulase activities. Cellulase of K. gibsonii CAC1 had K max of 7.4 X 10-2 mg/ml and V max of 6.7 X 10-1 µg/sec.The cellulase described in this work have many properties that are similar to those obtained from other microbial sources and may be useful for various industrial applications.

Production of cellulase by Mucor ramanniacus using submerged fermentation and its applications in biodegradation of agro-industrial waste

“…Highest activity was recorded at 50°C, 30°C and 60°C for Cellulomonas sp., K. gibsonii CAC1 enzyme and Geobacillus sp. (Adu et al 2015;Potprommanee et al 2017;Bai et al 2017) respectively. Cellulase activities from Trichoderma sp.…”