title: Performance and molecular evaluation of an anaerobic system with suspended biomass for treating wastewater with high fat content after enzymatic hydrolysis.
abstract: The effect of a lipase-rich fungal enzymatic preparation, produced by a Penicillium sp. during solid-state fermentation, was evaluated in an anaerobic digester treating dairy wastewater with 1200 mg of oil and grease/L. The oil and grease hydrolysis step was carried out with 0.1% (w/v) of solid enzymatic preparation at 30 degrees C for 24 h, and resulted in a final free acid concentration eight times higher than the initial value. The digester operated in sequential batches of 48 h at 30 degrees C for 245 days, and had high chemical oxygen demand (COD) removal efficiencies (around 90%) when fed with pre-hydrolyzed wastewater. However, when the pre-hydrolysis step was removed, the anaerobic digester performed poorly (with an average COD removal of 32%), as the oil and grease accumulated in the biomass and effluent oil and grease concentration increased throughout the operational period. PCR-DGGE analysis of the Bacteria and Archaea domains revealed remarkable differences in the microbial profiles in trials conducted with and without the pre-hydrolysis step, indicating that differences observed in overall parameters were intrinsically related to the microbial diversity of the anaerobic sludge.
authors: Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, Centro de Tecnologia, Bl. A, Sl. 539, Ilha do Fundão, 21949-900, Rio de Janeiro, Brazil.
authors: Daniela R
authors: DR
authors: Rosa
authors: Iolanda C S
authors: IC
authors: Duarte
authors: N Katia
authors: NK
authors: Saavedra
authors: Maria B
authors: MB
authors: Varesche
authors: Marcelo
authors: M
authors: Zaiat
authors: Magali C
authors: MC
authors: Cammarota
authors: Denise M G
authors: DM
authors: Freire
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000235:genetics; D001419:Bacteria / Q000235:genetics; D018533:Biomass; D006868:Hydrolysis; D008049:Lipase / Q000378:metabolism*; D008055:Lipids / Q000032:analysis*; D010100:Oxygen / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D014865:Waste Disposal, Fluid; D018508:Water Purification
chemical_list: D008055:Lipids; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D008049:Lipase; D010100:Oxygen