• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.371-378
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• 2013

Various microorganisms live in soil, of which those colonizing rhizosphere interact with nearby plants and tend to develop unique microbial communities. In this study, we isolated diverse actinomycetes from rhizosphere of rice (Oryza sativa L.) cultivated in fertilized (APK) and non-fertilized (NF) paddy soils, and investigated the diversity and antimicrobial activity of them. Using four kinds of selective media, 152 isolates were obtained from the soil samples and identified by determining 16S rRNA gene sequence. All of the isolates showed 99.0%~100.0% similarities with type strains and were classified into six genera: Dactylosporangium, Micromonospora, Kitasatospora, Promicromonospora, Streptomyces and Streptosporangium. Most of the isolates, 143 isolates, were classified into the genus Streptomyces. Additionally, many isolates had antimicrobial activity against plant pathogens, especially Magnaporthe oryzae (rice blast pathogen) in fungi. These findings demonstrated that rice rhizosphere can be a rich source of antagonistic actinomycetes producing diverse bioactive compounds.