Isolation of a Syntrophic Actinomycete Strain whose Growth Depend on Co-Culture with a Lysinibacillus Strain

Aims: A syntrophically growing actinomycete strain, designated Act-7, was isolated from Gunung Halimum mountain soil, West Java, Indonesia, and taxonomically characterized. Methodology and results: The strain Act-7 was isolated by the standard dilution technique using ISP 2 agar. It was identified and characterized based on the phenotypic, chemotaxonomic and genotypic methods. The phylogenetic analysis using 16S rRNA gene sequences suggested strain Act-7 belong to the genus Microtetraspora. The actinomycete strain required a diffusible compound for its growth from a spore-forming bacterial strain, designated D-2, which was identified as a member of the genus Lysinibacillus. Conclusion, significance and impact study: Isolation of syntrophic rare actinomycete is a good example for the discovery of uncultured or not-yet-cultured microorganisms by syntrophic growth response.