Xylan is the second most abundant naturally occurring renewable polysaccharide available on earth. It is a complex heteropolysaccharide consisting of different monosaccharides such asl-arabinose,d-galactose,d-mannoses and organic acids such as acetic acid, ferulic acid, glucuronic acid interwoven together with help of glycosidic and ester bonds. The breakdown of xylan is restricted due to its heterogeneous nature and it can be overcome by xylanases which are capable of cleaving the heterogeneous β-1,4-glycoside linkage. Xylanases are abundantly present in nature (e.g., molluscs, insects and microorganisms) and several microorganisms such as bacteria, fungi, yeast, and algae are used extensively for its production. Microbial xylanases show varying substrate specificities and biochemical properties which makes it suitable for various applications in industrial and biotechnological sectors. The suitability of xylanases for its application in food and feed, paper and pulp, textile, pharmaceuticals, and lignocellulosic biorefinery has led to an increase in demand of xylanases globally. The present review gives an insight of using microbial xylanases as an “Emerging Green Tool” along with its current status and future prospective.

A cellulase producing fungus Schizophyllum commune NAIMCC-F-03379 was isolated from decomposed leaf sample of Lantana camera. The nutritional components (wheat bran, magnesium sulphate and calcium chloride concentrations) and physical parameters (temperature and pH) were optimised by response surface methodology for enhanced cellulase production by S. commune NAIMCC-F-03379. The optimized medium contained: 1% (w/v) wheat bran, 0.3 g/L MgSO4, 0.8–1.0 g/L CaCl2, optimum temperature and pH were 25 °C and 5 respectively. Under optimum condition, 5.35-fold increase in CMCase and 6.62-fold increase in FPase activity was obtained as compared to un-optimized condition. Crude cellulase enzyme was subjected to different purification techniques and comparative evaluation of their efficiency was performed. The aqueous two-phase system using polyethylene glycol 8000/MnSO4 system showed maximum purification with 10.4-fold increase in activity, 79.5% yield and 0.5 partition coefficient. The cellulase enzyme obtained from S. commune NAIMCC-F-03379 has shown high stability i.e. more than 55% relative activity after 12 h of incubation over wide range of temperature (25–65 °C) and pH (3–10). The molecular weight of the cellulase enzyme was estimated as ~ 60 kDa by using sodium dodecyl sulphate-polyacrylamide electrophoresis (SDS-PAGE) and zymography. Km and Vmax value of cellulase on carboxy-methyl cellulose were obtained as 0.0909 mg/mL and 45.45 μmol/min mg respectively. Rice straw and wheat bran were subjected to hydrolysis using cellulase and cellulase–xylanase cocktail and analysed by thin layer chromatography and high performance liquid chromatography (HPLC). The HPLC analysis showed glucose concentration of 1.162 mg/mL after enzymatic hydrolysis of rice straw.