Actinomycetes are a taxonomic group of Gram-positive bacteria characterized by a high GC (guanine, cytosine) content in genomic DNA. Typical actinomycetes form branched hyphae and spores, and exhibit a variety of morphologies similar to filamentous fungi. They are mainly isolated from soil, but in recent years, many actinomycetes have been isolated from plants and marine environments. Actinomycetes also produce a wide variety of secondary metabolites, such as antibiotics, that are not involved in life support or growth and proliferation. It is said that more than 2 microbial antibiotic compounds have been discovered to date, and two-thirds of these are derived from actinomycetes.

　In a search for biologically active substances derived from actinomycetes, the research group isolated TPMA0078T, which forms orange colonies, from soil in Shinjuku, Tokyo. After comparative analysis of the genome sequence with closely related species and detailed analysis of morphology, cultural properties, and chemical taxonomic properties, the group discovered that the strain is a new species of the rare actinomycete genus Actinoplanes.

　They also confirmed that this strain produces the antibiotic kirromycin, which inhibits bacterial protein synthesis, and genome analysis revealed that it possesses biosynthetic genes capable of producing multiple antibiotics in addition to kirromycin.

　The results of this research are expected not only to deepen understanding of the diversity of actinomycetes, but also to contribute to securing biological resources, including genetic information that can be applied to the development of pharmaceutical seed compounds.

Paper information:【The Journal of Antibiotics】Actinoplanes kirromycinicus sp. nov., isolated from soil