Bacteria Genomes - BACILLUS HALODURANS

Bacillus halodurans is one of a group of rod-shaped, Gram-positive, aerobic or (under some conditions) anaerobic bacteria widely found in soil and water.

An alkaliphilic bacterium, strain C-125 (JCM9153), isolated in 1975, was identified as a member of the genus Bacillus and reported as a b-galactosidase and xylanase producer. It is the most thoroughly characterised strain, physiologically, biochemically, and genetically, among those in the collection of alkaliphilic Bacillus isolates. Recently, this strain was reidentified as Bacillus halodurans based on phylogenetic analysis using 16S rDNA sequence and DNA-DNA hybridisation analysis.

The B. halodurans genome contains 112 transposase genes, indicating that transposases have played an important evolutionary role in horizontal gene transfer and also in internal genetic rearrangement in the genome.

Out of 11 factors which belong to the extracytoplasmic function family, 10 are unique to B.halodurans, suggesting that they may have a role in the special mechanism for adaptation to an alkaline environment. The genome of B.halodurans is a single circular chromosome.

Bacillus halodurans produces many industrially useful alkaliphilic enzymes such as, protease (protein degrading enzyme), cellulase (cellulose degrading enzyme) and amylase (starch degrading enzyme). These enzymes are widely used as additives to laundry detergents. Bacillus halodurans also produces keratin decomposing enzyme which devolves keratinous proteins such as hair, nail and cock feathers which cause difficulty for their disposal. Bacillus halodurans also produces xylanase that bleaches pulp in the process of paper-making.

There is a specific interest in determining how the behaviour of Iss (insertion sequences) influences the improvement of enzyme productivity or the stability of enzyme production, because this may contribute to the development of some new theory on the basis of which systematic breeding of industrial strains can be pursued for further industrial application of alkaliphilic Bacillus strains possessing great potential for useful enzyme production.

References:

Nucleic Acids Research 28(21):4317-4331 (2000)
Journal of Bacteriology, 183: 4345-4356 (2001)
http://jura.ebi.ac.uk:8765/ext-genequiz/genomes/bh0011/
http://www.jamstec.go.jp/jamstec-e/PR/9908/0810b.html