[Objective] The purpose of this study is to study the acetylation of Pha E, one subunit of polyhydroxyalkanoate(PHA) synthase(Pha EC), and its function in PHA biosynthesis in Haloferax mediterranei. [Methods] PHA granules were collected by sucrose density gradient centrifugation. The acetylated sites of Pha E were identified by LC-MS/MS. The acetylated lysine(K) sites were mutated to arginine(R, mimics deacetylation) or glutamine(Q, mimics acetylation), and the mutated gene was knocked into the chromosome o...