International Journal of Technology 11(5) 921-930 (2020) Received June 2020 / Revised October 2020 / Accepted October 2020 International Journal of Technology http://ijtech.eng.ui.ac.id Cloning of DNA Polymerase I Geobacillus thermoleovorans SGAir0734 from a Batu Kuwung Hot Spring in Escherichia coli Kenny Lischer 1* , Kevin Priyono Tansil 1 , Mikael Januardi Ginting 1 , Muhamad Sahlan 1 , Anondho Wijanarko 1** , Masafumi Yohda 2 1 Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia 2 Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-city, Tokyo 184-8588, Japan Abstract. Access to biological engineering has become a critical point of modern science development through polymerase chain reaction (PCR). One of the main components in this process is DNA polymerase, which copies the main template DNA. However, there is a lack of studies on the production of DNA polymerase from indigenous thermophilic bacteria in Indonesia. To examine this process, DNA polymerase I gene (DNA pol I) from Geobacillus thermoleovorans (isolated from Batu Kuwung, Banten, Indonesia) was transformed into Escherichia coli. The gene was cloned by the cut and ligation method using NcoI and BamHI restriction enzymes, which were ligated with a pET23d vector. The recombinant gene was overexpressed in E. coli  and identified by using SDS-PAGE of 10% acrylamide gel, showing that the protein molecular weight was approximately  . This study successfully amplified the gene of interest, indicated by a high local similarity between the sequencing results and theoretical gene and positive intercellular protein expression. The results confirm that the study successfully cloned and synthesized recombinant DNA pol I of Geobacillus thermoleovorans from Batu Kuwung, Serang, Banten. Keywords: DNA pol I; DNA polymerase; Escherichia coli; Geobacillus thermoleovorans SGAir0734; Thermophilic bacteria 1. Introduction Polymerase chain reaction (PCR) is a widely known method to amplify a DNA strain and its complement. The PCR products are critical for biological engineering developments and breakthroughs. Many things can be achieved through PCR, including gene amplification and detection, disease detection, and the creation of genetically modified organisms (GMO) (Beyer et al., 2002). One of the components required for PCR reaction is DNA polymerase, also known as the main enzyme (Valones et al., 2009). Without DNA polymerase, the extension process as the main stage of PCR will not occur (Maddocks and Jenkins, 2017). In Indonesia, despite having access to PCR technology, almost all DNA polymerase is still imported. DNA polymerase in both current global and local markets mostly derives from thermophilic bacteria due to its higher resistance to denaturation and aggregation at high * Corresponding author’s email: lischer.kenny@ui.ac.id, Tel.: +62-87888017811; Fax: +60-04 979 8636 ** Corresponding author’s email: anondho@che.ui.ac.id, Tel.: +60-04 979 8626; Fax: +60-04 979 8636 doi: 10.14716/ijtech.v11i5.4311