Abstract
The biosynthetic mechanism of characteristic isoprenoidal lipid-core in halophilic archaea was investigated. The fate of deuterium from the stereospecifically deuterium-labeled leucine revealed the stereospecific conversion of prochiral hydrogen in leucine to isoprenoidal lipid with high efficiency. It suggest the involvement of isovaleryl-CoA dehydrogenase and leucine-mevalonate pathway through the biosynthesis of isoprenoid in halophilic archaea.