Biological characteristics and ability of Streptomyces rochei BT02 to inhibit the Ralstonia solanacearum causing bacterial wilt disease

In the agricultural field, actinomycetes are outstanding biological control agents to inhibit the growth of pathogenic microorganisms. Based on the manual of bacterial classification of the International Streptomyces Project (ISP) and the 16S-rRNA gene sequence, the actinomycete BT02 strain was named Streptomyces rochei BT02. This strain contains two polyketide synthase type I (pks-I) and polyketide synthase type II (pks-II) genes related to antibiotic synthesis. The result showed that the actinomycetes S. rochei BT02 grow well at 31οC, 1% salt, pH 7.0, and assimilate different carbon and nitrogen sources. The S. rochei BT02 showed antibacterial activity against three tested strains of Ralstonia solanacearum (Minimum inhibitory concentration =15 mg/ml). In greenhouse conditions, this strain reduced 43.5% the wilt disease index. That demonstrated that S. rochei BT02 could be a promising source for the production of bioproducts.