A simple and rapid method for the differentiation and identification of thermophilic bacteria

In total, 170 strains of thermophilic bacteria were isolated from deep-sea hydrothermal fields in the Pacific Ocean and a hot spring in Xiamen of China. To facilitate the identification of thermophilic strains, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole-cell proteins of these strains was first performed. The results showed that there exist four different protein patterns, indicating that the 170 strains might belong to four species or genera. The RAPD (random amplified polymorphic DNA) profiles of nine representative strains were consistent with those of SDS-PAGE. To further identify the species of the nine strains, their 16S rDNA sequences were analyzed. The results showed that the nine strains fell into four species of three genera, which was the same as revealed by SDS-PAGE. Therefore, SDS-PAGE of whole-cell proteins could be used as a rapid and simple method for the discrimination of thermophilic bacteria as the first step of species identification.