Enhanced production of bacterial xylanase and its utility in saccharification of sugarcane bagasse

An investigation was carried out using sugarcane bagasse as the agricultural residue to study the optimization of xylanase production by solid-state fermentation. Maximum xylanase production (20.35 U/g substrate) was achieved by Bacillus substilis subsp. subtilis JJBS250 using 'one variable at a time approach' at pH 7.0, 40 °C after 48 h. After statistical optimization by response surface methodology (RSM) there was 4.82-fold improvement in xylanase production (98.16 U/g substrate). Further optimization of untreated and sodium carbonate pretreated sugarcane bagasse enzymatic hydrolysis was carried out using both bacterial (Bacillus substilis subsp. subtilis JJBS250) and fungal (Myceliophthora thermophila BJTLRMDU3) xylanases that showed high amount of reducing sugar liberation from untreated sugarcane bagasse (124.24 mg/g substrate) as compared to pretreated (76.23 mg/g substrate) biomass. Furthermore, biophysical characterization of untreated and sodium carbonate pretreated sugarcane bagasse using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), revealed the structural changes in the pretreated biomass.