Two Novel Strains ( and Species) with Promising Potential for the Biocontrol of , the Causal Agent of Septoria Tritici Blotch of Wheat.

Two novel Algerian field-collected isolates were selected for their antifungal activity against (teleomorph ). The novel strains, termed Alg.24B1 and Alg.24B2, were identified as and since their respective nucleotide sequences of the 16S rRNA gene were 100% and 99.93% identical to those of and , respectively. The antifungal activities of Alg.24B1 and Alg.24B2 were evaluated by the well diffusion method and compared to those of other species. The maximum activity was obtained after two days of confrontation of the bacterial strain supernatants with the fungus for Alg.24B1 and three days for Alg.24B2. Furthermore, the metabolites responsible for the antifungal activity of both strains were detected by the investigation of either gene presence (PCR) or molecule production (activity detection of lytic enzymes and HPLC detection of lipopeptides). Overall, this study showed that in addition to their ability to produce lytic enzymes (protease and -glucanase), both strains coproduce three types of lipopeptides surfactin, iturin, and fengycin. Thus, the biofungicide activity of both strains may be a result of a combination of different mechanisms. Therefore, they had a great potential to be used as biocontrol agents to effectively manage septoria tritici blotch of wheat (STB).