A screening program to discover microorganisms that produce novel pesticides has yielded a new streptomycete strain that produces valinomycin, an insecticidal and acaricidal antibiotic. Bioassays of the crude culture broth produced by this strain demonstrated an LC50 to mosquito larvae of 10-3-10-4 dilution. Bioassays of the purified insecticide yielded LC50 values of 2-3 pm for mosquito larvae, 3 ppm for two-spotted spider mites, and 35 ppm for Mexican bean beetle larvae. Taxonomic studies indicated the valinomycin-producing microorganism was an atypical variant of Streptomyces griseus, which is hereby named var. flexipertum var. nov. Morphology and physiology of the new microorganism and production, isolation, and identification of the insecticidal metabolite are described.
All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences(all)