Selection of Polymerase-Producing Thermophilic Bacteria from Ijen Crater, East Java

Abstract

Thermophilic bacteria are a group of bacteria that adapt to environmental conditions with high temperatures, ranging from 45 ° - 90 ° C. as the ring of fire, Indonesia has many volcanic areas as the source of thermophilic bacteria, once is in Ijen Crater, East Java. Thermophilic bacteria have the potential to produce heat-resistant / thermostable enzymes such as polymerase. DNA polymerase is a key enzyme in amplification process of DNA fragment. The objective of this study was to found the novels thermophilic bacteria isolated from Ijen Crater which has potential to be the source of DNA polymerase production. This study was carried out by growing the bacterial strains on suitable media, followed with thermal screening (70-90⁰C), isolating and identifying the morphological and molecular characteristics of the selected isolates. Total of 12 isolates have selected after thermal screening in 70⁰C for, which were identified as positive and negative bacteria in gram staining assay. All the selected isolates found to have same colony color in white, but various types in shape, border, elevation, and border with. There were 4 isolates that selected after incubation in 90⁰C for 30 minutes, which were isolate 1, 5, 9, and 11. The DNA genome of four selected isolates then amplified using universal primer (16S rDNA) and pol1 to detect the presence of gene encoding polymerase. The result indicated that isolate 1, 5, 9, 11 were able to be the candidate thermophilic bacteria to produce DNA polymerase.