Print Email Facebook Twitter Glycosylated amyloid-like proteins in the structural extracellular polymers of aerobic granular sludge enriched with ammonium-oxidizing bacteria Title Glycosylated amyloid-like proteins in the structural extracellular polymers of aerobic granular sludge enriched with ammonium-oxidizing bacteria Author Lin, Y. (TU Delft BT/Environmental Biotechnology) Reino, Clara (Universitat Autònoma de Barcelona) Carrera, Julián (Universitat Autònoma de Barcelona) Pérez, Julio (TU Delft BT/Environmental Biotechnology) van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology) Date 2018 Abstract A new type of structural extracellular polymers (EPS) was extracted from aerobic granular sludge dominated by ammonium-oxidizing bacteria. It was analyzed by Raman and FTIR spectroscopy to characterize specific amino acids and protein secondary structure, and by SDS-PAGE with different stains to identify different glycoconjugates. Its intrinsic fluorescence was captured to visualize the location of the extracted EPS in the nitrifying granules, and its hydrogel-forming property was studied by rheometry. The extracted EPS is abundant with cross ß-sheet secondary structure, contains glycosylated proteins/polypeptides, and rich in tryptophan. It forms hydrogel with high mechanical strength. The extraction and discovery of glycosylated proteins and/or amyloids further shows that conventionally used extraction and characterization techniques are not adequate for the study of structural extracellular polymers in biofilms and/or granular sludge. Confirming amyloids secondary structure in such a complex sample is challengeable due to the possibility of amyloids glycosylation and self-assembly. A new definition of extracellular polymers components which includes glycosylated proteins and a better approach to studying them is required to stimulate biofilm research. Subject Aerobic granular sludgeAmmonium-oxidizing bacteriaAmyloidExtracellular polymeric substancesGlycoproteinsOA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:fd099e92-1b90-486d-8888-30b121a922a6 DOI https://doi.org/10.1002/mbo3.616 Source MicrobiologyOpen Part of collection Institutional Repository Document type journal article Rights © 2018 Y. Lin, Clara Reino, Julián Carrera, Julio Pérez, Mark C.M. van Loosdrecht Files PDF Lin_et_al_2017_MicrobiologyOpen.pdf 976.84 KB Close viewer /islandora/object/uuid:fd099e92-1b90-486d-8888-30b121a922a6/datastream/OBJ/view