Early biofouling detection using fluorescence-based extracellular enzyme activity

Babar Khalid Khan, Luca Fortunato, TorOve Leiknes

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Membrane-based filtration technologies have seen rapid inclusion in a variety of industrial processes, especially production of drinking water by desalination. Biological fouling of membranes is a challenge that leads to increased costs from efficiency reductions, membrane damage and ultimately, membrane replacement over time. Such costs can be mitigated by monitoring and optimizing cleaning processes for better prognosis. Monitoring bacterial accumulation in situ can therefore advance understanding of cleaning efficiency. A fluorescence-based sensor for early biofouling detection capable of measuring extracellular enzyme activity was developed and tested in a lab-scale seawater reverse osmosis (SWRO) biofouling model for use in monitoring bacterial accumulation proximal to the surface of a membrane. We tracked bacterial biomass accumulation rapidly and non-invasively using exogenously applied fluorogen-substrates and corroborated with optical coherence tomography imaging of the membrane surface in real-time. The selected fluorogen and fluorogen-substrate were characterized and down selected by high throughput screening in vitro for compatibility in seawater and profiled over relevant Red Sea desalination parameters (pH and temperature). This approach demonstrates the practicality of prototyping an early-detection biofouling sensor in membrane based processes, such as seawater desalination, using extracellular enzyme activity as a measure of bacterial abundance.
Original languageEnglish (US)
Pages (from-to)43-51
Number of pages9
JournalEnzyme and Microbial Technology
StatePublished - Oct 5 2018

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This study was supported by funding from King Abdullah University of Science and Technology (KAUST). TL and BK designed the study. BK performed experiments and analysis, interpreted the data and prepared the manuscript. LF performed all OCT acquisitions and visualizations. Fig. 1, Fig. 2 were produced by Xavier Pita, Fig. 3 was produced by Ivan Gromicho, both scientific illustrator at KAUST. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


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