ABSTRACT The aim of this study was to evaluate the behavior of an anaerobic reactor of packed-bed and continuous flow, in relation to the biogas and methane production and the removal of organic load, from the wastewater of cassava starch extraction. For this purpose, were tested, in a reactor with a useful volume of 2.82 L and support mean of polypropylene filled with polyethylene foam, the organic loading rate (OLR) of 2.5, 5.0, 8.0 and 10.0 g L-1d-1. It was evaluated the removal of COD, the pH, the VA/TA ratio, the biogas and the methane production. It was concluded from this study that it is possible to produce biogas with methane percentages higher than 80% (maximum) and remove the organic load more than 90% under the tested conditions. In relation to stability, the reactor can be considered stable for the parameters, pH, the relationship between volatile acidity and total alkalinity and organic load removal. The best results in relation to the average volumetric biogas production (0.174 and 0.311 L g COD-1) were obtained for the higher organic loading rate (of 8 and 10 g L-1d-1, respectively) and the observed tendency is that with the increase of the organic loading rate, the specific biogas production will increase as well as the specific production of methane.

Um fator limitante nas primeiras fases do cultivo do jundiá (Rhamdia quelen Quoy e Gaimard, 1824) é a presença da ictioftiríase. Os ácidos graxos poliinsaturados (PUFAs) presentes na dieta possuem uma potente atividade imuno-moduladora, e esta atividade depende da espécie analisada e da quantidade/qualidade dos PUFAs da dieta. O objetivo do presente estudo foi avaliar a resposta fisiológica de alevinos de jundiá, alimentados com diferentes fontes de ácidos graxos, quando parasitados pelo protozoário Ichthyophthirius multifiliis (Fouquet, 1876). Alevinos de jundiá (7,6±0,8g) alimentados durante sete semanas com cinco dietas contendo diferentes fontes lipídicas: óleos de peixe, linhaça e milho foram expostos ao protozoário. No quinto dia a presença da doença foi detectada. Amostras de sangue foram coletadas e sobrevivência e graus de infestação foram estimados. As diferentes dietas afetaram a sobrevivência dos alevinos, sendo que alevinos que consumiram dietas com óleo de peixe apresentaram uma maior sobrevivência. O hematócrito e o grau de infestação não apresentaram diferença estatística significativa entre os tratamentos, entretanto a contagem diferencial dos leucócitos registrou diferença. Os resultados mostraram pela primeira vez no jundiá que, diferentes fontes lipídicas produzem respostas fisiológicas diversas, podendo representar uma alternativa ao tratamento da doença. Novos estudos deverão ser realizados no sentido de aprofundar o conhecimento aqui gerado.

A limiting factor in the early stage of the jundiá (Rhamdia quelen Quoy; Gaimard, 1824) culture is the presence of diseases such as ichthyophthiriasis or "Ich". Dietary polyunsaturated fatty acids (PUFAs) have a potent immunomodulatory activity; and this activity depend of the fish species, quantity/quality of the dietary PUFAS. The aim of this study was evaluate the physiologic response ofjundiá, rather fed diets with different sources of fatty acids when challenge to Ich disease. Fingerlings ofjundiá (7.6±0.8g) were fed during seven weeks with five diets with a different lipid source: fish, linseed and corn oils. Then, the fish were challenged with the Ichthyophthirius multifiliis (Fouquet, 1876). On the 5th day, the presence of the disease was detected. Survival rate, blood samples and infection grade were recorded. Diets affect the survival rate of fingerlings, thus fish fed with diet with fish oil showed a higher survival. Hematocrit and infestation grade no recorder differences among treatment. The differential analysis of white blood cells shows difference. The results point out, at first time injundiá, that dietary lipids caused diversity physiologic response, this may be represent an opportunity for the disease treatment. New studies must be carrying out to deep knowledge found.