Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learned
Structural extracellular polymeric substances (EPS) contribute to the bioflocculation performance of activated sludge systems. This research investigates the potential of bioaugmentation of a structural EPS producer, Azoarcus communis, as a bioflocculation improvement or remediation approach. An ant...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IWA Publishing
2023-07-01
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| Series: | Water Practice and Technology |
| Subjects: | |
| Online Access: | http://wpt.iwaponline.com/content/18/7/1663 |
| _version_ | 1797745539304914944 |
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| author | An-Sofie Christiaens Robin Daenen Ilse Smets |
| author_facet | An-Sofie Christiaens Robin Daenen Ilse Smets |
| author_sort | An-Sofie Christiaens |
| collection | DOAJ |
| description | Structural extracellular polymeric substances (EPS) contribute to the bioflocculation performance of activated sludge systems. This research investigates the potential of bioaugmentation of a structural EPS producer, Azoarcus communis, as a bioflocculation improvement or remediation approach. An antibiotic-resistant and fluorescent protein-producing mutant was constructed to monitor the survival, persistence, and location of the augmented strain in the membrane bioreactor. Preliminary batch tests against a kaolin clay model system and deflocculated sludge revealed the flocculation potential of this strain. Morphological image analysis and fluorescence microscopy suggest that most of the bacteria augmented in suspension were initially attached to the sludge flocs with, however, only a limited fraction getting incorporated within the activated sludge floc biomass. This limited bioaugmentation prevented assessing its impact on bioflocculation and might be explained by metazoan and protozoan grazing, together with competition with indigenous organisms and sub-optimal growth conditions in the reactor for the engineered strain.
HIGHLIGHTS
The structural EPS producer Azoarcus is bioaugmented to enhance sludge bioflocculation.;
Augmentation with an antibiotic-resistant and fluorescent mutant strain ensures proper enumeration and localization.;
Azoarcus initially attached to sludge flocs but long-term persistence was limited.;
An MBR setup avoids initial washout but grazing by metazoa and protozoa remains a problem.; |
| first_indexed | 2024-03-12T15:24:44Z |
| format | Article |
| id | doaj.art-6d772c5b5e0641048c7d3655ee8dab1c |
| institution | Directory Open Access Journal |
| issn | 1751-231X |
| language | English |
| last_indexed | 2024-03-12T15:24:44Z |
| publishDate | 2023-07-01 |
| publisher | IWA Publishing |
| record_format | Article |
| series | Water Practice and Technology |
| spelling | doaj.art-6d772c5b5e0641048c7d3655ee8dab1c2023-08-10T14:05:30ZengIWA PublishingWater Practice and Technology1751-231X2023-07-011871663168010.2166/wpt.2023.103103Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learnedAn-Sofie Christiaens0Robin Daenen1Ilse Smets2 Chemical and Biochemical Reactor Engineering and Safety (CREaS), Chemical Engineering Department, KU Leuven, Celestijnenlaan 200f box 2424, 3001 Heverlee, Belgium Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium Chemical and Biochemical Reactor Engineering and Safety (CREaS), Chemical Engineering Department, KU Leuven, Celestijnenlaan 200f box 2424, 3001 Heverlee, Belgium Structural extracellular polymeric substances (EPS) contribute to the bioflocculation performance of activated sludge systems. This research investigates the potential of bioaugmentation of a structural EPS producer, Azoarcus communis, as a bioflocculation improvement or remediation approach. An antibiotic-resistant and fluorescent protein-producing mutant was constructed to monitor the survival, persistence, and location of the augmented strain in the membrane bioreactor. Preliminary batch tests against a kaolin clay model system and deflocculated sludge revealed the flocculation potential of this strain. Morphological image analysis and fluorescence microscopy suggest that most of the bacteria augmented in suspension were initially attached to the sludge flocs with, however, only a limited fraction getting incorporated within the activated sludge floc biomass. This limited bioaugmentation prevented assessing its impact on bioflocculation and might be explained by metazoan and protozoan grazing, together with competition with indigenous organisms and sub-optimal growth conditions in the reactor for the engineered strain. HIGHLIGHTS The structural EPS producer Azoarcus is bioaugmented to enhance sludge bioflocculation.; Augmentation with an antibiotic-resistant and fluorescent mutant strain ensures proper enumeration and localization.; Azoarcus initially attached to sludge flocs but long-term persistence was limited.; An MBR setup avoids initial washout but grazing by metazoa and protozoa remains a problem.;http://wpt.iwaponline.com/content/18/7/1663amyloid adhesinsbiological wastewater treatmentflocculation activityfluorescent protein |
| spellingShingle | An-Sofie Christiaens Robin Daenen Ilse Smets Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learned Water Practice and Technology amyloid adhesins biological wastewater treatment flocculation activity fluorescent protein |
| title | Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learned |
| title_full | Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learned |
| title_fullStr | Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learned |
| title_full_unstemmed | Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learned |
| title_short | Bioaugmentation of a structural extracellular polymeric substances (EPS) producer to improve activated sludge bioflocculation: lessons learned |
| title_sort | bioaugmentation of a structural extracellular polymeric substances eps producer to improve activated sludge bioflocculation lessons learned |
| topic | amyloid adhesins biological wastewater treatment flocculation activity fluorescent protein |
| url | http://wpt.iwaponline.com/content/18/7/1663 |
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