Recombinant Approaches for Microbial Xylanases: Recent Advances and Perspectives

Xylanases are crucial enzymes to hydrolyse the xylan of plant hemicellulose in order to complete the carbon cycle. Xylanases have been used widely in a variety of industries ranging from food and feed industry to pulp and paper industry. Most of the industrial processes which using xylanase requires a thermostable and alkali stable enzyme. Therefore it is desired to produce high thermostable and alkali stable xylanase with high activity. In this review a number of molecular techniques are used in this genomic era have been utilized to enhance physiological properties of xylanases for greater commercial application in the industries. A brief outline of diverse molecular techniques such as genome-walking PCR, thermal asymmetric interlaced PCR (TAIL-PCR), staggered extension process (StEP) recombination method, site-directed mutagenesis together with metagenomic approaches have been discussed which are used to improve the charactestics of xylanases and its production. Metagenomic studies along with directed evolution by mutant creation have also been reported as an effective tool in improvement of xylanase activity and its properties. This review comprehensively describes the recent reports and different combinatorial approaches towards production of efficient xylanases.