Abstract This manuscript addresses the use of dairy manure wastewater (DMW) as a substrate for methane production in a high rate system - two serial UASB reactors - and the characterization of the effluent in the different phases of the treatment. Two experimental conditions were applied. In the first, the organic load rate (OLR) was 6.2 gCODtotal L-1 d-1 and the hydraulic retention time (HRT) was 12 days, whereas in experiment 2 they were 14.2 gCODtotal L-1 d-1 and 7.5 days, respectively. The reactors showed a high capacity of removal of COD and solids, i.e., above 71%, which led to bioenergy productivities of 0.55 and 0.73 L CH4 L-1 d-1 in experiments 1 and 2,respectively. The methane yield in UASB1 was 0.19 and 0.08 L CH4g CODrem.-1, respectively, inexperiments 1 and 2. The methane yield in UASB1 was greater than UASB2, with approximately 70% of methane content in the biogas in this reactor.The effluent characterization showed micro and macronutrients - some in high concentrations, as nitrogen, phosphorous, K, and Fe between 12.1 and 521.4 mg L-1, and others in low concentrations, as Ca, Mg, Zn and Mn between 0.6 and 13 mg L-1. Na was not removed from the UASB systems and its concentration in the effluent was raised to 23.5% in comparison with the substrate.

RESUMOA infecção por algumas espécies ou genótipos de Cryptosporidiumrepresenta um risco em potencial para a saúde pública, principalmente por causa de morbidade e mortalidade em crianças de zero a cinco anos de idade e em pacientes imunodeprimidos. Embora existam alguns relatos de infecção por Cryptosporidiumem animais de companhia, sua participação na epidemiologia da criptosporidiose humana é incerta, e a literatura sobre esse tema ainda é bastante escassa. O objetivo deste estudo foi determinar a ocorrência e realizar a classificação molecular deCryptosporidiumspp. em amostras fecais de animais exóticos criados como animais de estimação no Brasil. Um total de 386 amostras de seis espécies de animais foi colhido e armazenado em solução de dicromato de potássio 5% a 4°C. Os oocistos foram purificados por centrífugo-sedimentação em água/éter, seguindo-se a extração de DNA genômico e a realização da nestedPCR para amplificação de fragmento parcial do gene da subunidade 18S do rRNA. Positividade para Cryptosporidiumspp. foi observada em 11,40% (44/386) das amostras. O sequenciamento de fragmentos amplificados permitiu a identificação de Cryptosporidium tyzzeri em camundongos,Cryptosporidium murisem camundongos, hamster e chinchila, Cryptosporidium parvumem chinchila, Cryptosporidiumgenótipo hamsterem hamstere Cryptosporidiumsp. em porquinho-da-índia. Os resultados deste estudo mostram que há uma variedade de espécies de Cryptosporidiumpresentes em animais exóticos de companhia no Brasil. Os dados sugerem que esses animais podem participar da epidemiologia da criptosporidiose humana, particularmente por seu estreito convívio.

ABSTRACTInfection by some species or genotypes of Cryptosporidium represents a potential risk to public health, mainly because of the morbidity and mortality in children from zero to five years of age and in immunocompromised patients. Although there are some reports of Cryptosporidium infection in animals raised as pets, their participation in the epidemiology of human cryptosporidiosis is uncertain and studies on this topic are still scarce. The aim of this study was to determine the occurrence, as well as to perform the molecular classification of Cryptosporidium spp. in faecal samples of exotic animals raised as pets in Brazil. A total of 386 faecal samples from six species of animals was collected and stored in a solution 5% potassium dichromate at 4°C. The oocysts were purified by centrifugal sedimentation in water-ether, followed by genomic DNA extraction and the performance of the nested-PCR to amplify a partial fragment of 18S rRNA gene. Positivity for Cryptosporidium spp. was obtained in 11.40% (44/386) of samples. The sequencing of the amplified fragments allowed the identification of Cryptosporidium tyzzeri in mice, Cryptosporidium muris in mice, hamster and chinchilla, Cryptosporidium parvum in chinchilla, Cryptosporidium hamster genotype in hamster and Cryptosporidium sp. in guinea pig. The results of this study show that there is a variety of species of Cryptosporidium present in exotic animals raised as pets in Brazil. The data suggest that these animals may have zoonotic potential and participate in the epidemiology of human cryptosporidiosis.