RESUMO The biostimulating potential of algae extracts represents an opportunity to increase efficiency in food production. Cultivable microalgae are viable candidates due to the high production capacity. In this work, the chemical composition and effect of the microalgae extract Scenedesmus acuminatus (Lagerh.) Chodat and commercial product AMPEP (Acadian Marine Plant Extract Powder) derived from the macroalgae Ascophyllum nodosum (L.) Le Jol. on the germination of BRS Estilo bean seeds were evaluated. The treatments analyzed the methodology of exposure of seeds to extracts: soaking for 5 hours (T1) and applications every 48 hours (T2). The parameters evaluated were: germination percentage (PG), speed index (IVG) and mean germination time (TMG). The values of PG and IVG were higher in T2, representing about 50% higher yield than T1. In relation to chemical composition, Scenedesmus acuminatus extract obtained higher levels of proteins and carbohydrates. Thus, S. acuminatus is a potential producer of biostimulant extracts, while beans obtained lower germinative performance when submitted to the soaking process.