Predominance of syntrophic bacteria, Methanosaeta and Methanoculleus in a two-stage up-flow anaerobic sludge blanket reactor treating coffee processing wastewater at high organic loading rate

Made available in DSpace on 2018-12-11T17:21:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-11-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The effect of the organic loading rate (OLR) on the performance and microbial composition of a two-stage UASB system treating coffee processing wastewater was assessed. The system was operated with OLR up to 18.2 g COD (L d)−1 and effluent recirculation. Methane production and effluent characteristics were monitored. The microbial composition was examined through next-generation sequencing and qPCR from the anaerobic sludge of the first reactor (R1) operated at low and high OLR. The system showed operational stability, obtaining a maximum methane production of 2.2 L CH4 (L d)−1, with a removal efficiency of COD and phenolic compounds of 84 and 73%, respectively. The performance of R1 at high OLR in steady conditions was associated with an appropriate proportion of nutrients (particularly Fe) and a marked increase of the syntrophic bacteria Syntrophus and Candidatus Cloacimonas, and acetoclastic and hydrogenotrophic methanogens, mainly Methanosaeta, Methanoculleus, Methanobacterium and Methanomassiliicoccus. Post-Graduate Program in Agricultural and Livestock Microbiology São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences, Jaboticabal Laboratory of Environmental Sanitation Department of Rural Engineering São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences, Jaboticabal Laboratory of Biochemistry and Molecular Biology Department of Technology São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences, Jaboticabal Faculty of Technology, Jaboticabal Embrapa Informática Agropecuária, Campinas Post-Graduate Program in Agricultural and Livestock Microbiology São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences, Jaboticabal Laboratory of Environmental Sanitation Department of Rural Engineering São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences, Jaboticabal Laboratory of Biochemistry and Molecular Biology Department of Technology São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences, Jaboticabal