Understanding of aerobic granulation enhanced by starvation in the perspective of quorum sensing
Journal
Applied Microbiology and Biotechnology
Journal Volume
100
Journal Issue
8
Pages
3747-3755
Date Issued
2016
Author(s)
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. ? 2015, Springer-Verlag Berlin Heidelberg.
Subjects
Aerobic granulation
Autoinducer-2 (AI-2)
Cell adhesiveness
Extracellular polymeric substances (EPS)
Microbial community
Starvation
Type
journal article