Premium
Distribution characteristics of extracellular polymeric substances and cells of aerobic granules cultivated in a continuous‐flow airlift reactor
Author(s) -
Zhou Dandan,
Dong Shuangshi,
Gao Linlin,
Liu Mengyuan,
Niu Shu
Publication year - 2013
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.3927
Subject(s) - granulation , extracellular polymeric substance , granule (geology) , airlift , bioreactor , scanning electron microscope , chemical engineering , chemistry , confocal laser scanning microscopy , polysaccharide , extracellular , biofilm , materials science , chromatography , biophysics , bacteria , biology , biochemistry , composite material , organic chemistry , engineering , genetics
BACKGROUND: Most studies on the cultivation of aerobic granules to date have been based on the sequencing batch reactor ( SBR ). A continuous flow airlift fluidized bed reactor ( CAFB ) was set up, and the operating conditions which promoted granulation in the SBR were not controlled. The distribution characteristics of extracellular polymeric substances ( EPS ) and cells of the aerobic granules were studied under these operating conditions. RESULTS: Cells, polysaccharide and protein were all distributed uniformly throughout the granules, confirmed by both confocal laser scanning microscopy and scanning electron microscopy observations. However, for the granules in the SBR , the core of the granules was usually composed of protein and dead cells, and living cells survived only in their outer layers. Such a distribution of granules in the CAFB was confirmed to be related to the advanced oxygen transfer ability and strong shear force in the CAFB . Even microbial cells in the center were supplied with sufficient food to maintain bioactivity. Thus, the CAFB performed COD removal very efficiently. CONCLUSION: Cells and EPS in the aerobic granules of a CAFB were more uniformly distributed compared with those in granules of the reported SBR reactors, owing to the particular operating conditions of the CAFB . © 2012 Society of Chemical Industry