Maximizing cellulase and xylanase production from Novel Bacillus pumilus strain isolated from agricultural waste compost in Egypt and optimizing their activities

Several lignocellulose-degrading bacterial isolates from agricultural residue compost were isolated from Egypt and identified based on 16S rRNA gene sequence. One of these isolates is a novel Bacillus pumilus strain CX9 (GenBank accession number: MW532148), this strain exhibited potent cellulase and xylanase activities. In this study, the optimum conditions for this strain to produce xylanase and cellulase were determined. The highest production of cellulase was obtained at the following conditions: incubation temperature 35 °C, pH 8.0, shaking speed 150 rpm, incubation time 3 days, carboxymethylcellulose (CMC) as a carbon source and ammonium nitrate as a nitrogen source. On the other hand, xylanase production was maximal at 35 °C, pH 8.0, shaking speed 150 rpm, incubation time 2 days, xylan as a carbon source and ammonium nitrate as a nitrogen source. The highest activities of cellulase and xylanase produced by Bacillus pumilus strain CX9 were obtained at 55 °C and pH 6 after 60 min of enzyme incubation time. The thermostable nature of cellulase and xylanase produced by Bacillus pumilus strain CX9 could be beneficial for the lignocellulosic wastes decomposition and might be preferable for industrial applications including biofuel production.