AHL-mediated quorum sensing regulates the variations of microbial community and sludge properties of aerobic granular sludge under low organic loading. (September 2019)

• Record Type: Journal Article
• Authors: Chen, Han; Li, Ang; Cui, Chongwei; Ma, Fang; Cui, Di; Zhao, Heping; Wang, Qilin; Ni, Bingjie; Yang, Jixian
• Is Part Of: Environment international. Volume 130(2019)
• Publication Date: 2019-09
• Subjects: AHL N-acyl-homoserine lactones -- S-AHL AHL in the sludge phase -- W-AHL AHL in the water phase -- C4-HSL N-butyryl homoserine lactone -- C6-HSL N-hexanoyl homoserine lactone -- C8-HSL N-octanoyl homoserine lactone -- C10-HSL N-decanoyl homoserine lactone -- C12-HSL N-dodecanoyl homoserine lactone -- C14-HSL N-tetradecanoyl homoserine lactone -- 3OC6-HSL N-(β-ketocaproyl) homoserine lactone -- 3OC8-HSL N-(3-oxooctanoyl) homoserine lactone -- 3OC10-HSL N-(3-oxodecanoyl) homoserine lactone -- 3OC12-HSL N-(3-oxododecanoyl) homoserine lactone -- 3OC14-HSL N-(3-oxotetradecanoyl) homoserine lactone; Aerobic granular sludge -- Extracellular polymeric substances -- Quorum sensing -- Microbial community -- Low organic loading rate; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2019.104946
• Languages: English
• ISSNs: 0160-4120

Abstract

Abstract: Aerobic granular sludge (AGS) is promising in wastewater treatment. However, the formation and existence of AGS under low organic loading rate (OLR) is still not fully understood due to a knowledge gap in the variations and correlations of N -acyl-homoserine lactones (AHLs), the microbial community, extracellular polymeric substances (EPS) and other physiochemical granule properties. This study comprehensively investigated the AHL-mediated quorum sensing (QS) and microbial community characters in the AGS fed with ammonium-rich wastewater under a low OLR of 0.15 kg COD (m 3 d) −1 . The results showed that the AGS appeared within 90 days, and the size of mature granules was over 700 μm with strong settleability and ammonium removal performance. More tightly-bound extracellular polysaccharide and tightly-bound extracelluar protein were produced in the larger AGS. C10-HSL and C12-HSL gradually became dominant in sludge, and short-chain AHLs dominated in water. EPS producers and autotrophic nitrifiers were successfully retained in the AGS under low OLR. AHL-mediated QS utilized C10-HSL, C12-HSL and 3OC6-HSL as the critical AHLs to regulate the TB-EPS in aerobic granulation, and autotrophic nitrifiers may perform interspecific communication with C10-HSL. The correlations of bacterial genera with AGS properties and AHLs were complex due to the dynamic fluctuations of microbial composition and other variable factors in the mixed-culture system. These findings confirmed the participation of AHL-mediated QS in the regulation of microbial community characters and AGS properties under low OLR, which may provide guidance for the operation of AGS systems under low OLR from a microbiological viewpoint. Graphical abstract: Unlabelled Image Highlights: Successful aerobic granulation is achieved at a low OLR of 0.15 kg COD (m 3 d) −1 . EPS producers and autotrophic nitrifiers successfully survive under low OLR. AHL-mediated QS regulates the EPS production with 3OC6-HSL, C10-HSL and C12-HSL. Autotrophic nitrifiers may perform interspecific communication with C10-HSL.