Screening genetic markers for the environmental impact of sugarcane vinasse on the annelid potworm Enchytraeus crypticus

Abstract

Sugarcane vinasse, a byproduct of ethanol production, is currently being used as a fertilizer in the agricultural sector in Brazil. However, fertirrigation in excess and for long periods has caused environmental problems such as soil acidification and contamination of ground and surface water, among others. Classical ecotoxicological assays (survival and reproductive endpoints) have been important tools for analyzing the implications of the intense use of vinasse on biota and evaluating its environmental impact. Previous toxicity tests showed a reduced enchytraeid reproduction at high doses, but an increased reproduction at intermediate dilutions of vinasse. However, these tests do not provide information on the molecular mechanisms underlying these opposing effects, which is crucial to understand the ecological impact of vinasse application. Combining genetic markers, such as changes in gene expression patterns or methylation status that are indicative of physiological changes in the organism, with classical ecotoxicological tests will be a more accurate tool for assessing both the long-term ecological risk of vinasse contamination and understanding its mode of action. Therefore, the aim of this research is to evaluate the effects of sugarcane vinasse and beet vinasse on gene expression patterns of the terrestrial Oligochaeta Enchytraeus crypticus. We expect changed in gene regulation to occur in the enchytraeids, evidenced by the presence of down-regulated or up-regulated genes in vinasse-exposed animals that are indicative of phenotypic effects. These genetic and phenotypic effects will help unraveling the consequences of long-term vinasse exposures in this relevant group of soil organisms. (AU)