title: Long-term storage of aerobic granules in liquid media: viable but non-culturable status.
abstract: Long-term storage and successful reactivation after storage are essential for practical applications of aerobic granules on wastewater treatment. This study cultivated aerobic granules (SI) in sequencing batch reactors and then stored the granules at 4 °C in five liquid media (DI water (SW), acetone (SA), acetone/isoamyl acetate mix (SAA), saline water (SS), and formaldehyde (SF)) for over 1 year. The first four granules were then successfully reactivated in 24h cultivation. The specific oxygen uptake rates (SOUR) of the granules followed SI>SS>SA>SAA>SW>SF; and the corresponding granular strengths (10 min ultrasound) followed SI>SA=SS>SAA>SW>>SF. During storage the granular cells secreted excess quantities of cyclic-diguanylate (c-di-GMP) and pentaphosphate (ppGpp) as responses to the stringent challenges. We proposed that to force cells in granules (Alphaproteobacteria, Flavobacteria, Betaproteobacteria, Gammaproteobacteria, Actinobacteria, Sphingobacteria, and Clostridia) entering viable but non-culturable (VBNC) status is the key of success for extended period storage of granules.
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, 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: Qinlan
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; 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: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Yayi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Jieni
authors.initials: J
authors.lastname: Li
mesh_terms: D000332:Aerobiosis; D019149:Bioreactors / Q000382:microbiology*; D003470:Culture Media; D046508:Culture Techniques; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D003470:Culture Media; D062065:Wastewater
keywords: Aerobic granules; High throughput sequencing; Signaling molecules; Storage; Viable but non-culturable status