Estudo da biodegradação de glicerina em processos de cofermentação com melaço de cana-de-açúcar

Abstract

This work proposed to study biodegradation of glycerol in co-fermentation processes with cane molasses, in order to produce compounds of commercial value using wild microorganisms. In the first experiment, whose purpose was to isolate microorganisms with glycerol degradative ability it was used as sources of these microorganisms water samples from two sewage treatment ponds, one of a dairy industry and the other of the starch manufacturer. These samples were inoculated on Petri plates containing a solid culture medium and subsequently these were incubated at 37 ° C for 72 hours. After the incubation time several microorganisms growth, but only two yeast samples were isolated, each one originated from different effluent treatment pond. To confirm they were yeast samples, visual analysis of the colony characteristics were conducted for confirming yeast samples. It was also analyzed the cells morphology of these two yeasts by Gram’s Method, showing that both were negative cocci. In the second experiment such yeast were inoculated in two different fermentation broths (1: 1 to 2: 1 glycerol: Molasses) with the purpose of verifying the influence of glycerol and molasses proportions and the fermentation time for the production of metabolites. Finally, high-performance liquid chromatography (HPLC) was applied to identify metabolites being them acetic acid, lactic acid and citric acid. However, only the concentration of acetic acid was possible to quantify . According to the obtained data, the formulation that produced the highest concentration of acetic acid was 2: 1 (glycerol: Molasses) with approximately 0.2 g / L after 48 hours of fermentation process.