Optimization of Cellulase and Xylanase Production by Micrococcus Species under Submerged Fermentation

This paper reports on the optimization of culture conditions for cellulase and xylanase production by bacterial isolate from lignocellulosic biomass. The bacterial isolate was screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC) and birch wood xylan as substrates, respectively. One bacterial isolate showing the highest halo zone diameter (isolate PLY1) was selected for detailed studies. The analysis of the 16S ribosomal ribonucleic acid (rRNA) gene nucleotide sequence of PLY1 revealed it to have 98% similarity to Micrococcus luteus strain Fse9 and the sequence was deposited in the GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371. Cellulase production was achieved in the presence of CMC (1% w / v ) under an incubation temperature of 25 °C (198 U/mL), pH 5 (173 U/mL), agitation speed 50 rpm (173 U/mL) and incubation period of 96 h (102 U/mL). Xylanase was produced maximally when birch wood xylan (1% w / v ) was used as the substrate at 25 °C (1007 U/mL), pH 10 (2487 U/mL), 200 rpm (1814 U/mL), and under an incubation period of 84 h (1296 U/mL). Our findings showed that Micrococcus sp. SAMRC-UFH3 appears to be a potentially important candidate for lignocellulosic waste degradation and other relevant industrial applications.