[en] Streptomyces scabiei is the causative agent of the common scab (CS) disease on tuber and root crops (potatoes, radishes, beets,¿). However, the colonization by S. scabiei is never lethal for the host and is mainly affecting the visual appearance of the tubers. Among all the microorganisms causing problems in potato agro-system, tremendous economic losses are caused by the oomycete Phytophthora infestans responsible for the late blight disease. Bearing in mind the rich arsenal of bioactive specialized metabolites of Streptomyces, and the common host preference of these two microorganisms, the first aim of this work was to search for conditions that allow S. scabiei to display antagonizing activities against P. infestans, thereby possibly highlighting a plant-protecting role of S. scabiei. Once proper antagonizing conditions identified, we aim at i) identifying the nutrients responsible for the observed activity, ii) the type of metabolites, and iii) the identity of the bioactive compounds responsible for the anti-oomycete activity.
