ATP Modulates the Growth of Specific Microbial Strains Ming Li • Sung-Kwon Lee • Seung Hwan Yang • Jung Hwan Ko • Jeong Sun Han • Tae-Jong Kim • Joo-Won Suh Received: 18 January 2010 / Accepted: 7 May 2010 / Published online: 30 May 2010 Ó Springer Science+Business Media, LLC 2010 Abstract The regulatory function of extracellular ATP (exATP) in bacteria is unknown, but recent studies have demonstrated exATP induced enhanced secondary metabo- lite production and morphological differentiation in Strep- tomyces coelicolor. The growth of Streptomyces coelicolor, however, was unaffected by exATP, although changes in growth are common phenotypes. To identify bacteria whose growth is altered by exATP, we measured exATP-induced population changes in fast-growing microbes and actino- mycetes in compost. Compared with the water-treated con- trol, the addition of 10 ml 100 lM ATP to 10 g of compost enhanced the actinomycetes population by 30% and decreased fast-growing microbial numbers by 20%. Eight microbes from each group were selected from the most populated colony, based on appearance. Of the eight isolated fast-growing microbes, the 16S rRNA sequences of three isolates were similar to the plant pathogens Serratia pro- teamaculans and Sphingomonas melonis, and one was close to a human pathogen, Elizabethkingia meningoseptica. The growth of all fast-growing microbes was inhibited by ATP, which was confirmed in Pseudomonas syringae DC3000, a pathogenic plant bacterium. The growth of six of eight iso- lated actinomycetes strains, all of which were identified as close to Streptomyces neyagawaensis, was enhanced by ATP treatment. This study suggests that exATP regulates bacte- rial physiology and that the exATP response system is a target for the control of bacterial ecology. Introduction In animal and plant cell systems, extracellular ATP (exATP) in tissues regulates cellular physiology [13, 14, 16, 17, 28]. The microorganism Streptomyces coelicolor increased antibiotic production and morphological differentiation after ATP treatment in growth media [22], suggesting that exATP has regulatory effects on bacteria as well. If exATP is a regulatory effector, it might alter additional aspects of bacterial physiology, such as growth rate, as has been observed in animal [27] and plant [26] cells. Li et al. [22], however, did not document any apparent growth changes by Streptomyces coelicolor A3(2) after exATP treatment. Here, we report that a compost screen identified several micro- organisms whose growth was affected by exATP and demonstrated that exATP influences bacterial growth in a strain-specific manner. Plant rhizospheres contain diverse beneficial and path- ogenic microbes. By controlling the microbial balance in the rhizospheres by enhancing the growth of beneficial bacteria and suppressing the growth of pathogenic bacteria, Electronic supplementary material The online version of this article (doi:10.1007/s00284-010-9677-3) contains supplementary material, which is available to authorized users. M. Li Á S.-K. Lee Á S. H. Yang Á J. H. Ko Á J. S. Han Á J.-W. Suh (&) Division of Bioscience and Bioinformatics, College of Natural Science, Myongji University, Cheoin-gu, Yongin, Gyeonggi-Do 449-728, South Korea e-mail: jwsuh@mju.ac.kr T.-J. Kim (&) Department of Forest Products and Biotechnology, College of Forest Science, Kookmin University, Seongbuk-gu, Seoul 136-702, South Korea e-mail: bigbell@kookmin.ac.kr Present Address: M. Li Center of Molecular Pharmaceutics, School of Chemical Engineering Dalian University of Technology, Dalian, Liaoning 116023, People’s Republic of China 123 Curr Microbiol (2011) 62:84–89 DOI 10.1007/s00284-010-9677-3