title: Understanding of aerobic granulation enhanced by starvation in the perspective of quorum sensing.
abstract: Three sequencing batch reactors (M1, M2, and M3) were set up to investigate the influence of different lengths of starvation time (3, 5, and 7 h) on aerobic granulation in the perspective of quorum sensing (QS). Autoinducer-2 (AI-2) level was quantified to evaluate the QS ability of aerobic granules. The results indicated that AI-2 level increased steadily during a cycle of sequencing batch reactors, suggesting that starvation was closely related to AI-2 secretion. In the long-term operation, aerobic granules cultivated using a prolonged starvation period had a better integrity and a higher level of cell adhesiveness despite a slower formation speed. With the extension of the starvation period, the total amount of extracellular polymeric substances (EPS) displayed an increasing tendency. EPS with large molecular weight (MW) also reached a higher level using a prolonged starvation period. However, a higher level of AI-2 and cell adhesiveness was observed in M2, which might be related to more stable granules. The results implied that the starvation period could trigger AI-2 secretion and promoted the production of large MW EPS, leading to cell adhesiveness enhancement and granule formation. Therefore, a combination of different starvation periods was proposed in this study in order to improve aerobic granulation.
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, No. 220 Handan Road, Yangpu District, Shanghai, 200433, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, No. 220 Handan Road, Yangpu District, Shanghai, 200433, China.
authors.forename: Supu
authors.initials: S
authors.lastname: Sun
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, No. 220 Handan Road, Yangpu District, Shanghai, 200433, China.
authors.forename: Buyun
authors.initials: B
authors.lastname: Ma
authors.affiliation: Shanghai Municipal Engineering Design General Institute, Shanghai, 200092, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, No. 220 Handan Road, Yangpu District, Shanghai, 200433, China. hitwan@163.com.
authors.forename: Chunli
authors.initials: C
authors.lastname: Wan
authors.affiliation: Department of Chemical Engineering, National Taiwan University, Taipei, 106, Taiwan. djlee@ntu.edu.tw.
authors.forename: Duu-Jong
authors.initials: DJ
authors.lastname: Lee
mesh_terms: D000332:Aerobiosis; D001419:Bacteria / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001422:Bacterial Adhesion; D018407:Bacterial Physiological Phenomena; D019149:Bioreactors / Q000382:microbiology*; D003470:Culture Media / Q000378:metabolism; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D053038:Quorum Sensing; D012722:Sewage / Q000382:microbiology
chemical_list: D003470:Culture Media; D012722:Sewage; D010100:Oxygen
keywords: Aerobic granulation; Autoinducer-2 (AI-2); Cell adhesiveness; Extracellular polymeric substances (EPS); Microbial community; Starvation