ABSTRACT

A great number of ubiquitous Bacillus species have been often isolated from various terrestrial and deep-sea environments, even from the Mariana Trench at the depth of 10897 m. Some of those Bacillus species possess various capabilities to adapt to extreme environments such as high and low temperature, high and low pH, and high salinity (Priest 1993, Takami 1999a). In fact, numerous microorganisms have been isolated from deepsea sediments collected at depths ranging from 1050 to 10897 m located at near the south part of Japan (Takami et al. 1997, 1999a). Among these deep-sea isolates, many extremophilic bacteria such as alkaliphiles, halophiles and thermophiles were found, which would be expected to thrive in an extreme environment different from the in situ conditions of high hydrostatic pressure and low temperature in the deep-sea sampling sites (Takami et al. 1999a). The whole genomic sequences from alkaliphilic B. halodurans (Takami et al. 2000) and neutrophilic B. subtilis (Kunst et al. 1997) have been determined. Very recently, the complete nucleotide sequence of the genome of extremely halotolerant and alkaliphilic Oceanobacillus iheyensis isolated from the deep-sea sediment collected at 1050 m depth has been determined (Takami et al. 2003). These sequences from two alkaliphilic Bacillus related species highlighted common genes involved in the alkaliphilic phenotype.