Iranian Research Organization for Science and Technology (IROST) Microbiology, Metabolites and Biotechnology 2980-8855 3 2 2020 11 01 Controlled turgidity; a simple and efficient method for transformation of Halobacterium salinarum R1. 121 128 1155 10.22104/armmt.2022.5591.1066 EN Ali Asghar Deldar Department of Biotechnology, Faculty of Chemistry and Chemical Engineering,Malek Ashtar University of Technology,Tehran, Iran Neda Mokari Bonabi Department of Biotechnology, Faculty of Chemistry and Chemical Engineering, Malek Ashter University of Technology, Tehran, Iran Azadeh Mirfeizollahi National Institute of Genetic Engineering and Biotechnology, Institute of industrial and Environmental biotechnology, Tehran, IRAN Ayman Bazzaz Department of Biotechnology, Faculty of Chemistry and Chemical Engineering, Malek Ashtar University of Technology, Tehran,Iran Journal Article 2022 04 09 <em>Halobacterium salinarum</em> as a model organism has been used for archeal genomics studies in many investigations. This well-known microorganism loves hyper saline habitat and transformation of DNA for genetic manipulation of the halophile by conventional methods eg. electroporation is impossible and current specific procedure is time consuming, sensitive and difficult. Therefore the development of easy and efficient methods for genetic manipulation especially transformation of this species are important. In this study we introduced a simple method for <em>H. salinarum</em> transformation with high efficiency. This method is based on the controlled short time swelling- deswelling of this halobacterium. Exposure of the halophile to hypo-osmotic shock was done by adding deionized water containing the desired plasmid to the cell suspension that decreased NaCl concentration to around 2.5 M. After 60 seconds the shock removed by the re-increasing salt concentration of suspension to 3.3M. During the osmotic shock plasmids from low concentrated fluid gets sucked in through the cell membrane. Transformation confirmed by PCR and colony count. In comparison with conventional PEG mediated method the frequency of 10⁵ transformants/µg of DNA revealed that osmotic shock is an efficient transformation method in <em>H. salinarum</em>. Consequently this easy and fast transformation method could be used instead of other laborious methods in this microorganism and probably to transform other halophiles https://mmb.irost.ir/article_1155_285f89b802bcb2651801455c86d78f2a.pdf