BIOPROCESS APPLIED TO THE TREATMENT OF RESIDUAL WATERS OF COFFEE WET PROCESSING FOR THE INCORPORATION OF SELECTED YEAST STRAINS

O objetivo deste trabalho foi isolar cepas de leveduras capazes de degradar a agua de degomagem do beneficiamento umido do cafe, caracterizando os metabolitos formados. A bebida preparada a partir de graos tratados por via umida e considerada de melhor qualidade quando comparada a elaborada com graos tratados por via seca. No entanto, o alto potencial poluente da agua residual do beneficiamento representa serio problema para o ambiente. A agua de degomagem apresenta essencialmente contaminacao orgânica, com taxas de demanda bioquimica de oxigenio (DBO) e demanda quimica de oxigenio (DQO) superiores a 20.000 mgO2/L. Candida tropicalis, C. lypolitica, C. guilliermondii, C. parapsilopsis, Kloeckera apiculata e Rhodotorula rubra, isoladas de cerejas de cafe, foram inoculadas em frascos contendo agua de degomagem e esses, submetidos a agitacao constante(120 rpm) por 48 horas, a 28oC. Candida parapsilopsis apresentou percentual de reducao da taxa de DBO de 50,14% e de DQO de 29,81%, evidenciando a viabilidade do uso desses microrganismos como biodespoluentes. DESENVOLVIMENTO DE BIOPROCESSO APLICADO AO TRATAMENTO DE AGUAS RESIDUAIS DO BENEFICIAMENTO UMIDO DO CAFE PELA INCORPORACAO DE LINHAGEM SELECIONADA DE LEVEDURAS Abstract The aim of the present work was to isolate yeast strains able to degrade the degumming water originated from the wet processing of coffee, characterizing the formed metabolites. The drink prepared from the treated grains by wet processing is considered of better quality when compared with the grains treated by dry process. However, the great polluent potential of the residual water from this processing represents serious concern for the environment. The degumming water essentially presents organic contamination, with Oxygen Biochemical Demand (OBD) and Oxygen Chemical Demand (OCD) rates superior to 20.000 mgO2/L. Candida tropicalis, C. lypolitica, C. guilliermondii, C. parapsilopsis, Kloeckera apiculata e Rhodotorula rubra, isolated from coffee cheeries were inoculated in flasks containing the degumming water and then submitted to constant agitation (120 rpm) for 48 hours at 28oC. The isolated species revealed capacity to degrade the substrate, however C.parapsilopsis showed reduction percentages of OBD and OCD rates of 50.14% e 29.81%, respectivelly, showing the viability of the use of those microorganisms as biological depollutants.