S J Jo1, S-Y Jeong2, H Kwon1, S H Lee3, H-S Oh4, T Yi5, P-K Park6, C-H Lee1, T G Kim2. 1. School of Chemical and Biological Engineering, Seoul National University, Seoul, Republic of Korea. 2. Department of Microbiology, Pusan National University, Pusan, Republic of Korea. 3. Department of Earth Sciences, University of Minnesota, Twin Cities, Minneapolis, MN, USA. 4. Department of Environmental Engineering, Seoul National University of Science and Technology, Seoul, Republic of Korea. 5. National Institute of Ecology, Seocheon, Republic of Korea. 6. Department of Environmental Engineering, Yonsei University, Wonju, Republic of Korea.
Abstract
AIMS: Quorum quenching (QQ) is an attractive strategy for mitigating biofouling in membrane bioreactors (MBRs). However, the effects of QQ on the activated sludge (AS) process have not been adequately evaluated. This study investigated the long-term effects of QQ on a laboratory-scale anoxic-oxic MBR, focusing on AS performance and microbial community. METHODS AND RESULTS: Anoxic-oxic MBRs with and without QQ were operated for 91 days. QQ did not affect COD and TN removal efficiencies over the experimental period, during which its activity remained >90%. QQ reduced floc size by approximately 8% but had no effect on biomass concentration. AS microbial communities were regularly analysed using massively parallel sequencing. AS bacterial communities were temporally dynamic irrespective of QQ presence, for example, a temporal increase in bacterial diversity and a temporal decay of community similarity. QQ counteracted the temporal change in diversity and the temporal distance-community decay. Community comparison revealed that QQ changed the successional trajectory of the AS community at a late period, because it decelerated temporal changes of specific members, such as Thiothrix and Sphingomonadaceae*. Correlation networks revealed that QQ increased network clustering, complexity and density. The combined results suggest that the tighter microbial association by QQ increased the community resistance. CONCLUSIONS: QQ can enhance the diversity and stability of the AS community in MBR by counteracting the innate temporal change in community structure. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings are useful for the further advancement of QQ-based strategies in engineered microbial environments.
AIMS: Quorum quenching (QQ) is an attractive strategy for mitigating biofouling in membrane bioreactors (MBRs). However, the effects of QQ on the activated sludge (AS) process have not been adequately evaluated. This study investigated the long-term effects of QQ on a laboratory-scale anoxic-oxic MBR, focusing on AS performance and microbial community. METHODS AND RESULTS: Anoxic-oxic MBRs with and without QQ were operated for 91 days. QQ did not affect COD and TN removal efficiencies over the experimental period, during which its activity remained >90%. QQ reduced floc size by approximately 8% but had no effect on biomass concentration. AS microbial communities were regularly analysed using massively parallel sequencing. AS bacterial communities were temporally dynamic irrespective of QQ presence, for example, a temporal increase in bacterial diversity and a temporal decay of community similarity. QQ counteracted the temporal change in diversity and the temporal distance-community decay. Community comparison revealed that QQ changed the successional trajectory of the AS community at a late period, because it decelerated temporal changes of specific members, such as Thiothrix and Sphingomonadaceae*. Correlation networks revealed that QQ increased network clustering, complexity and density. The combined results suggest that the tighter microbial association by QQ increased the community resistance. CONCLUSIONS: QQ can enhance the diversity and stability of the AS community in MBR by counteracting the innate temporal change in community structure. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings are useful for the further advancement of QQ-based strategies in engineered microbial environments.
Authors: Nikolai V Ravin; Simona Rossetti; Alexey V Beletsky; Vitaly V Kadnikov; Tatyana S Rudenko; Dmitry D Smolyakov; Marina I Moskvitina; Maria V Gureeva; Andrey V Mardanov; Margarita Yu Grabovich Journal: Microorganisms Date: 2022-06-27
Authors: Nikolai V Ravin; Tatyana S Rudenko; Dmitry D Smolyakov; Alexey V Beletsky; Maria V Gureeva; Olga S Samylina; Margarita Yu Grabovich Journal: Int J Mol Sci Date: 2022-08-23 Impact factor: 6.208