Isolation and characterization of Gram negative obligate and facultative alkalophilic Bacillus sp. from desert soil of Saudi Arabia

Abstract

Five new alkalophilic strains were isolated from soil samples collected from the western region of Saudi Arabia. They were identified by partial sequencing of 16s rRNA polymerase chain reaction (PCR) amplicons and morphological and biochemical characterization. Two of the isolates (number 2 and 3) were found to be facultative alkalophiles, while the other three (numbers 1, 4 and 5) were found to be obligate alkalophiles. Total protein profile analysis using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed no significant differences between isolates No. 2 and No. 3. On the other hand, there were major differences recognized in the banding pattern of the protein for isolate numbers 1, 4 and 5. All the isolates were 98% identical to Bacillus cohnii at the 16s rRNA gene.

Key words: Bacillus cohnii, 16SrRNA, Alkalophilic bacteria.