title: Formation of bacterial aerobic granules: Role of propionate.
abstract: Propionate presents as one of the major volatile fatty acids in municipal wastewaters, which are not readily degraded as acetate by microorganisms. This study cultivated aerobic granules from column reactors with acetate, acetate/propionate mix (3:1 and 1:3) and propionate as carbon sources and noted that propionate-rich feed would delay granulation, but could generate granules with high structural strength. Propionate feed enriched strains fractionated into the hydrophobic phase, Sphaerotilus sp., Sphingomonadaceae and Thauera sp., in granules and altered hydrophobicity of Thauera sp. and Zoogloea sp. The enriched strains could secret high quantities of cyclic-di-diguanylate to increase production of extracellular polymeric substances (EPS). The hydrophobic cell surface and increased EPS quantity led to integrated propionate-fed granules. Feed with high propionate concentration is proposed as promising way to cultivate strong aerobic granules for practical use.
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Chunli
authors.initials: C
authors.lastname: Wan
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Si
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wen
authors.affiliation: Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan. Electronic address: djlee@ntu.edu.tw.
authors.forename: Duu-Jong
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
mesh_terms: D000085:Acetates / Q000378:metabolism; D000332:Aerobiosis; D019149:Bioreactors / Q000382:microbiology*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D059013:Microbial Consortia / Q000502:physiology*; D011422:Propionates / Q000378:metabolism*; D020628:Thauera / Q000737:chemistry / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000295:instrumentation; D062065:Wastewater / Q000737:chemistry
chemical_list: D000085:Acetates; D006152:Cyclic GMP; D011422:Propionates; D062065:Wastewater; C062025:bis(3',5')-cyclic diguanylic acid
keywords: Aerobic granules; Exopolysaccharides; Hydrophilic; Hydrophobic; Propionate