Screening of xylanase producing bacteria and identification of xylanase genes

Abstract

Xylanase is the enzyme for xylan depolymerization which degrade the linear polysaccharide beta-1,4-xylan into xylose, thus breaking down hemicellulose, one of the major components of plant cell walls. The enzyme have been extensively studied and could potentially be employed for the production of hydrolysate from agro-industrial wastes, nutritional improvements of lignocellulosic feeds, processing of food and increasing animal feed digestibility, biobleaching of paper pulp. Also, the enzyme degrading compound (xylose) can be use for bio-ethanol fermentation. Xylanase producing bacteria were screened with different selection plates which were sampled from from Chuuk (Micronesia) and Jeju (Republic of Korea). Activity were tested by simple DNS method with 96 well plate. The screened bacteria were identified with 16s rRNA sequences. Several primers were designed based on each identified strains for amplification of patial xylanase sequences. PCR were carried out with each differant conditions. The purified PCR products were ligated into pGEM easy T vector and transformed into E. coli DH5alpha. Plasmid DNA were extracted with Plasmid DNA extraction Kit and the sequencing was carried out by Solgent inc. (Korea). The beta-glucosidase nucleotide sequences were analyzed by nucleotide Blast (NCBI) and DNassist 2.2 programs.