Diversity of Microorganisms Related to Biocorrosion in Ethanol Samples

摘要

Ethanol is the most common alcohol and a renewable energy source that can be produced from biomass. Brazil and the United States are world leaders in ethanol production, using as raw material sugar cane and corn, respectively. In Brazil, ethanol is used as automotive fuel in two forms: hydrated, used in ethanol-using cars and flex fuel cars; or anhydrous alcohol, which is added to gasoline. Ethanol is capable of being metabolized by various microorganisms serving as a carbon source for them. Under favorable conditions, bacteria and fungi can form biofilms and participate actively in the process of biocorrosion. The presence of some microorganisms in the biofilms may enhance corrosion by the production of corrosive metabolites such as organic acids. Given the scarcity of studies in the area, this work aimed to study the diversity of microorganisms present in samples of ethanol in order to identify possible causes of the process of biocorrosion. For this, several samples of ethanol from different origins were received and analyzed. The main groups of cultivable microorganisms related to biocorrosion were quantified. Furthermore, analyses of non-cultivable microorganisms were performed using molecular biology techniques. The results allow a better assessment of the susceptibility of storage tanks and pipelines to microbiological corrosion in the presence of ethanol.