Polyhydroxyalkanoate (PHA) is stored as an important carbon and energy source in bacterial cells. For biomedical applications, gram-positive bacteria can be better sources of PHAs, since they lack outer membrane lipopolysaccharide. Although gram-positive Streptomyces coelicolor A3(2) has been indicated as a high potential PHA producer, phaC gene that encodes the key enzyme PHA synthase in the metabolic pathway is not determined in its genome. BLAST search results of the GenBank database argued that SCO7613 could specify a putative polyhydroxyalkanoate synthase (PhaC) responsible for PHA biosynthesis. | Turkish Journal of Biology Turk J Biol 2021 45 275-286 http biology TÜBİTAK Research Article doi biy-2011-16 Polyhydroxyalkanoate accumulation in Streptomyces coelicolor affected by SCO7613 gene region 1 1 3 2 1 Zeynep DEMİR ÖKSÜZ Tuğrul DORUK Nevin YAĞCI Sedef TUNCA GEDİK 1 Molecular Biology and Genetic Department Faculty of Science Gebze Technical University Kocaeli Turkey 2 Department of Environmental Engineering Faculty of Civil Engineering İstanbul Technical University İstanbul Turkey 3 Molecular Biology and Genetic Department Faculty of Arts and Science Ondokuz Mayıs University Samsun Turkey Received Accepted Published Online Final Version Abstract Polyhydroxyalkanoate PHA is stored as an important carbon and energy source in bacterial cells. For biomedical applicati- ons gram-positive bacteria can be better sources of PHAs since they lack outer membrane lipopolysaccharide. Although gram-positive Streptomyces coelicolor A3 2 has been indicated as a high potential PHA producer phaC gene that encodes the key enzyme PHA syntha- se in the metabolic pathway is not determined in its genome. BLAST search results of the GenBank database argued that SCO7613 could specify a putative polyhydroxyalkanoate synthase PhaC responsible for PHA biosynthesis. Deduced amino acid sequence of SCO7613 showed the presence of conserved lipase box like sequence 555GASAG559 in which serine residue was present as the active nucleophile. Present study describes deletion of putative S. coelicolor phaC gene via PCR dependent method. We showed that SCO7613 is not an essential gene in S. coelicolor and its deletion affected PHA accumulation negatively although it is not ceased. Transcomplementation abolished the mutant phenotype demonstrating that the decrease in PHA resulted from the deletion of SCO7613. Key words Streptomyces coelicolor SCO7613 polyhydroxyalkanoate synthase phaC glycerol 1. Introduction of bacteria could be
