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Membrane Water Treatment Volume 14, Number 1, January 2023 , pages 35-45 DOI: https://doi.org/10.12989/mwt.2023.14.1.035 |
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 open accessApplication of acyl-homoserine lactones for regulating biofilm characteristics on PAO1 and multi-strains in membrane bioreactor |
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Wonjung Song, Chehyeun Kim, Jiwon Han, Jihoon Lee, Zikang Jiang and Jihyang Kweon
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| Abstract | ||
| Biofilms significantly affect the performance of wastewater treatment processes in which biodegradability of numerous microorganisms are actively involved, and various technologies have been applied to secure microbial biofilms. Understanding changes in biofilm characteristics by regulating expression of signaling molecules is important to control and regulate biofilms in membrane bioreactor, i.e., biofouling. This study investigated effects of addition of acyl-homoserine lactones (AHL) as a controllable factor for the microbial signaling system on biofilm formation of Pseudomonas aeruginosa PAO1 and multiple strains in membrane bioreactor. The addition of three AHL, i.e., C4-, C6-, and C8-HSL, at a concentration of 200 μg/L, enhanced the formation of the PAO1 biofilm and the degree of increases in the biofilm formation of PAO1 were 70.2%, 76.6%, and 72.9%, respectively. The improvement of biofilm formation of individual strains by C4-HSL was an average of 68%, and the microbial consortia increased by approximately 52.1% in the presence of 200 μg/L C4-HSL. CLSM images showed that more bacterial cells were present on the membrane surface after the AHL application. In the COMSTAT results, biomass and thickness were increased up to 2.2 times (PAO1) and 1.6 times (multi-strains) by C4-HSL. This study clearly showed that biofilm formation was increased by the application of AHL to individual strain groups, including PAO1 and microbial consortia, and significant increases were observed when 50 or 100 μg/L AHL was administered. This suggests that AHL application can improve the biofilm formation of microorganisms, which could yield an enhancement in efficiency of biofilm control, such as in various biofilm reactors including membrane bioreactor and bioflocculent systems in water/wastewater treatment processes. | ||
| Key Words | ||
| acyl-homoserine lactones; biofilm formation; PVDF membrane; Quorum sensing | ||
| Address | ||
| Wonjung Song: The Academy of Applied Science and Technology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea Chehyeun Kim, Jiwon Han, Jihoon Lee, Zikang Jiang and Jihyang Kweon: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea | ||
