Extratos hidrolisados de biomassa de Chlorella sp. como bioestimulante para sementes.

Abstract

The increasing demand for food is proportional to population growth, leading us to seek new technologies aimed at enhancing techniques in food cultivation, focusing on greater resistance to biotic and abiotic stresses, resulting in higher crop productivity with reduced losses from planting to harvesting. However, most inputs used end up having a negative impact on the environment, harming and contaminating soil, water, and air, besides carrying harmful substances to human health to the consumer's table. In this context, the need to ensure food security and promote sustainable agricultural practices motivates the development of bioinputs, while also being environmentally friendly. In this regard, this study aimed to develop bio-stimulants based on the microalgae Chlorella sp. through acid hydrolysis. The evaluation of the bio-stimulant potential occurred through the analysis of lettuce and onion seed germination, carried out both in the laboratory and in a germination chamber. The characterization of the bio-stimulants was performed regarding antioxidant potential, carbohydrate profile, amino acid profile, hormone-like effect, lipid content, and presence of metals. The results showed that, compared to the control group (treated only with water), the hydrolysates prepared with sulfuric acid at concentrations of 0.25% and 0.75% and equally diluted to 15% showed the best results in the lettuce seed germination process. The germination of onion seeds did not show better results than the control (water). The hydrolysates presented compounds such as monosaccharides, lipids, amino acids, and volatile organic compounds, which may be crucial for plant development and their resistance to stresses. Therefore, it is concluded that the Chlorella sp. microalgae hydrolysate has bio-stimulant potential for lettuce seeds.