Polyphosphate, which is synthesized by the enzyme polyP kinase (PPK), is an important energy and phosphate storage polymer that plays a crucial role in the regulation of adaptive responses of cells to physical and chemical stresses. | Turk J Biol 36 (2012) 373-380 © TÜBİTAK doi: Deletion of polyphosphate kinase gene (ppk) has a stimulatory effect on actinorhodin production by Streptomyces coelicolor A3(2) İrem YALIM CAMCI, Tuğrul DORUK, Ümmehan AVİCAN, Sedef TUNCA GEDİK Gebze Institute of Technology, Faculty of Sciences, Department of Molecular Biology and Genetics, 41400 Gebze, Kocaeli - TURKEY Received: ● Accepted: Abstract: Polyphosphate, which is synthesized by the enzyme polyP kinase (PPK), is an important energy and phosphate storage polymer that plays a crucial role in the regulation of adaptive responses of cells to physical and chemical stresses. In this work, the polyphosphate kinase gene (ppk) of Streptomyces coelicolor was deleted, and the effect of this mutation on actinorhodin and undecylprodigiosin biosynthesis was investigated. Deletion of the ppk gene had a stimulatory effect on actinorhodin production; the mutant strain produced about 5 times more antibiotic compared to the wild type strain at 120 h of growth. There was no difference in undecylprodigiosin production between the mutant and wild-type strains. In the presence of a selective antibiotic, the mutant strain could grow only on rich medium and could not sporulate effectively. Moreover, while the wild type strain was resistant, the mutant strain was sensitive to H2O2 in the conditions tested. Mutant characters were complemented by the ppk gene, which is cloned on a high copy number plasmid. Key words: Streptomyces, polyP, polyphosphate kinase, ppk, antibiotic production Introduction Polyphosphate (polyP) is found in the cells of every archeon, bacterium, fungus, plant, insect, and mammal. It is a linear polymer of phosphate molecules joined together by high-energy anhydride bonds (1). This polymer is synthesized by polyP kinase (PPK) using the terminal phosphate of ATP as the substrate (2) and degraded to inorganic phosphate by endopolyphosphatase (PPN) .
