Molecular and biotechnological aspects of xylanases.

Hemicellulolytic microorganisms play a significant role in nature by recycling hemicellulose, one of the main components of plant polysaccharides. Xylanases (EC 3.2.

Genetic transfer of thermophilic trait from alkalophilic thermophilic Bacillus to E.coli.

The genomic library of alkalophilic thermophilic Bacillus was constructed in E.coli. A single recombinant [pATB 507 I] out of 10,000 colonies showed growth at 50 degrees C, which produced large, opaque and mucilaginous colonies on LB.

Expression of the cloned xylanases from an alkalophilic, thermophilic Bacillus in Bacillus subtilis.

A recombinant plasmid construct, pLPX6.5, harbouring a 6.5 kb Hind III fragment of genomic DNA, from an alkalophilic, thermophilic Bacillus NCIM 59 and coding for xylanase activity, was electroporatically transformed into Bacillus subtilis MI 111.

Chromosomal gene integration and enhanced xylanase production in an alkalophilic thermophilic Bacillus sp. (NCIM 59).

Chromosomal integration and xylanase gene amplification were demonstrated for the first time in an alkalophilic thermophilic Bacillus sp. (NCIM 59). The integrants were characterized by larger zone of xylan clearance than the parent culture and hybridization with vector (pUC8) DNA.

Cloning and extracellular expression in Escherichia coli of xylanases from an alkaliphilic thermophilic Bacillus sp. NCIM 59.

A genomic DNA library of an alkaliphilic thermophilic Bacillus was constructed in Escherichia coli with pUC 8 vector and was screened using a Congo red xylan plate clearance assay. Six xylanase positive transformants having identical inserts showed immunological reactivity towards polyclonal antibodies raised against purified xylanase (M(r) 15,800) from the Bacillus. A 4.