Streptomyces hilarionis sp. nov. and Streptomyces hayashii sp. nov., two new strains associated with potato scab in Brazil

Abstract

Two new actinobacteria, designated strains IBSBF 2807^T and IBSBF 2953^T, isolated from scab lesions on potato tubers grown in the southern Brazilian states of Rio Grande do Sul and Santa Catarina, respectively, were characterized and identified through a polyphasic approach. Phylogenetic analyses of 16S rRNA sequences revealed that these two strains belong to the genus Streptomyces. Multilocus sequence analysis using five concatenated genes, atpD, gyrB, recA, rpoB and trpB, allocated strains IBSBF 2807^T and IBSBF 2953^T in distinct branches of Streptomyces phytopathogenic strains. PCR-RFLP analysis of the atpD gene also confirmed that these strains differ from the type strains of Streptomyces associated with potato scab. The morphological, physiological and biochemical characterization, along with the overall genome-related index properties, indicated that these two strains could be distinguished from their closest phylogenetic relatives and each other. According to the data, IBSBF 2807^T and IBSBF 2953^T represent two new Streptomyces species related to potato scab. The proposed names for these strains are Streptomyces hilarionis sp. nov. (IBSBF 2807^T=CBMAI 2674^T=ICMP 24297^T=MUM 22.66^T) and Streptomyces hayashii sp. nov (IBSBF 2953^T=CBMAI 2675^T=ICMP 24301^T=MUM 22.68^T).

Keywords: Streptomyces sp. nov.; phytopathology; polyphasic taxonomy.; potato scab.