The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal.

RESUMO Com o objetivo de determinar a prevalência de aglutininas anti-Leptospira spp., foi realizado um inquérito sorológico em 131 suínos abatidos no matadouro público de Patos, Estado da Paraíba, Brasil. Para o diagnóstico sorológico de leptospirose, foi utilizada a técnica de soroaglutinação microscópica (SAM), utilizando-se culturas vivas de 22 sorovares patogênicos e dois sorovares saprófitos de Leptospira spp. Para a determinação do sorovar mais provável, foram considerados o título de aglutininas e a freqüência de soros reagentes. Soros que apresentaram títulos iguais para dois ou mais sorovares foram excluídos desta análise. Dos 131 suínos, 44 foram soropositivos para pelo menos um dos sorovares empregados, resultando em uma soroprevalência de 33,6% (IC 95% = 25,5% 42,4%). O sorovar mais provável foi o Pomona, com 38 (29,0%; IC 95% = 21,4% – 37,6%) soros reagentes. Também foram constatadas reações sorológicas para os seguintes sorovares: Pyrogenes (2,3%; IC 95% = 0,5% – 6,5%), Canicola (1,5%; IC 95% = 0,2% – 5,4%) e Shermani (0,8%; IC 95% = 0,02% – 4,2%). Houve diferença significativa na soroprevalência para o sorovar Pomona em relação aos demais sorovares (P < 0,0001).

ABSTRACT A serologic survey was conducted among 131 swine slaughtered in the public slaughterhouse of Patos city, Northeast region of Brazil, to determine the prevalence of anti-Leptospira spp. agglutinins. For serologic diagnosis of leptospirosis, the microscopic agglutination test (MAT) was carried out using live cultures of 22 pathogenic and two saprophytic Leptospira spp. serovars. The most frequent serovar was found crossing the results of frequency and titer of agglutinins, and sera presenting equal titers for two or more serovars were not considered for this analysis. Of the 131 swine analyzed, 44 were seropositive for at least one Leptospira spp. serovar, resulting in a seroprevalence of 33.6% (95% CI = 25.5% 42.4%). The most frequent serovar was Pomona, with 38 (29.0%; 95% CI = 21.4% 37.6%) reactant sera. Other reactant serovars and respective prevalence were: Pyrogenes (2.3%; 95% CI = 0.5% 6.5%), Canicola (1.5%; 95% CI = 0.2% 5.4%) and Shermani (0.8%; 95% CI = 0.02% 4.2%). There was statistical difference in seroprevalence to serovar Pomona compared with others reactant serovars (P < 0.0001).