title: A miniature porous aluminum oxide-based flow-cell for online water quality monitoring using bacterial sensor cells.
abstract: The use of live bacterial reporters as sensing entities in whole-cell biosensors allows the investigation of the biological effects of a tested sample, as well as the bioavailability of its components. Here we present a proof of concept for a new design for online continuous water monitoring flow-cell biosensor, incorporating recombinant reporter bacteria, engineered to generate an optical signal (fluorescent or bioluminescent) in the presence of the target compound(s). At the heart of the flow-cell is a disposable chip made of porous aluminum oxide (PAO), which retains the sensor microorganisms on its rigid planar surface, while its high porosity allows an undisturbed access both to the sample and to essential nutrients. The ability of the bacterial reporters to detect model toxic chemicals was first demonstrated using a "naked" PAO chip placed on solid agar, and later in a chip encased in a specially designed flow-through configuration which enables continuous on-line monitoring. The applicability of the PAO chip to simultaneous online detection of diverse groups of chemicals was demonstrated by the incorporation of a 6-member sensor array into the flow-through chip. The selective response of the array was also confirmed in spiked municipal wastewater effluents. Sensing activity was retained by the bacteria after 12-weeks storage of freeze-dried biochips, demonstrating the biochip potential as a simple minimal maintenance "plug-in" cartridge. This low-cost and easy to handle PAO-based flow-cell biosensor may serve as a basis for a future platform for water quality monitoring.
authors.affiliation: Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Sharon
authors.initials: S
authors.lastname: Yagur-Kroll
authors.affiliation: LioniX, Enschede, Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Schreuder
authors.affiliation: MicroDish BV, Utrecht, Netherlands.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Ingham
authors.affiliation: LioniX, Enschede, Netherlands.
authors.forename: René
authors.initials: R
authors.lastname: Heideman
authors.affiliation: Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Rachel
authors.initials: R
authors.lastname: Rosen
authors.affiliation: Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. Electronic address: shimshon.belkin@mail.huji.ac.il.
authors.forename: Shimshon
authors.initials: S
authors.lastname: Belkin
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D018407:Bacterial Physiological Phenomena / Q000187:drug effects*; D001681:Biological Assay / Q000295:instrumentation*; D019149:Bioreactors / Q000382:microbiology; D015374:Biosensing Techniques / Q000295:instrumentation; D004209:Disposable Equipment; D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation*; D008163:Luminescent Measurements / Q000295:instrumentation; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008904:Miniaturization; D016062:Porosity; D014159:Transducers; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000494:pharmacology; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D000537:Aluminum Oxide
keywords: Bioluminescence; Fluorescence; On-line monitoring; Porous aluminum oxide; Toxicity; Whole-cell bioreporters