A bleaching herbicidal activity of methoxyhygromycin (MHM) produced by an actinomycete strainStreptomycessp. 8E-12

AIMS: To screen bioherbicidal isolates and evaluate herbicidal activity of methoxyhygromycin (MHM) produced by Streptomyces sp. 8E-12. METHODS AND RESULTS: Streptomyces sp. 8E-12 with herbicidal activity was selected through seed germination bioassay. An active metabolite, MHM was isolated from culture broth by carbon absorption, butanol extraction, silica gel, Sephadex LH-20 and G-10 chromatography, and preparative HPLC. The metabolite was identified by electrospray ionization mass spectra (ESI-MS) and 1H- and 13C-NMR spectral data analyses. In vivo herbicidal activity was examined against weeds and crops grown on pots. CONCLUSIONS: Streptomyces sp. 8E-12 produced a selective herbicidal metabolite which was identified as MHM. The metabolite showed stronger in vivo activity against monocotyledonous plants than dicotyledonous plants, and caused a bleaching (albino symptom) on some weeds including Digitaria sanguinalis and Echinochloa crus-galli. SIGNIFICANCE AND IMPACT OF THE STUDY: These results showed that Streptomyces sp. 8E-12 produced a bioherbicidal metabolite, MHM and can be developed as a biocontrol agent (BCA) for weed control.