Molecular Detection of Lipase A Gene in Bacillus Subtilis Strains Isolated from Soil

Many researchers have focused their attention on finding new sources of lipase because of the widespread use of this enzyme in the industry. Soil is a rich source for lipase and therefore the present study was undertaken to screen the Iranian soil for the Bacillus subtilis lipase gene. The soil was collected from different areas of Isfahan, Iran and bacterial colonies were obtained from these samples. These colonies were examined by their physical appearance, biochemical tests and PCR amplification of a portion of their genomic DNA. The obtained results indicate that although from their physical appearance, many colonies were initially selected as being Bacillus subtilis, only four were identified so using biochemical tests. PCR amplification of the genome of these colonies indicated that lipase A was present in all four samples. However the intensity of the bands were different correlating to the differences obtained from the biochemical tests. Upon further investigation it became evident that PCR conditions were not optimum suggesting that altering these conditions can be used as a tool for detecting the differences between these genes. Also the SSCP experiments demonstrated a polymorphism of this gene among these samples. In conclusion, we have characterized an easy and reliable method for the detection of lipase gene from Bacillus subtilis strains. With this method some strains from the Iranian soil were detected and by further screening of the soil, industrially more favorable lipases can be identified.