Inorganic Cadmium Detection Using a Fluorescent Whole-Cell Bacterial Bioreporter

Elcin, Evrim
Öktem, Hüseyin Avni
Cadmium pollution has become a serious environmental issue due to its toxicity and frequent entrance into environment components such as soil, water, and air via many anthropogenic sources. Over the last two decades, whole-cell bacterial bioreporters have been acknowledged as bio-sentinels for the determination of toxic heavy metals. Herein a sensitive and quite specific bacterial bioreporter was developed to cope with the need for the rapid and simple determination of cadmium. The construction and characterization of a fluorescence-based whole-cell cadmium bioreporter strain, Escherichia coli MG1655 (pBR-PzntA), was described which is based on the expression of green fluorescent protein under the control of the zntA gene promoter of heavy metal resistance determinant. The developed bioreporter was able determine cadmium at 5 mu g/L after 3.5 hours of induction in a defined medium while the cadmium detection limit was improved to 2 mu g/L after 1.5 hours by the use of an inorganic phosphate-limiting defined medium. Drastic changes in cadmium sensitivity were obtained between bioreporter cells induced at different growth phases. The maximum fluorescence performance was obtained for early exponential growth phase cells. This cadmium bioreporter was found to be more sensitive and specific to cadmium ions than to a wide range of heavy metals and was sensitive to only cadmium at drinking water quality standard concentrations. These findings will lead to future studies including integration of the bioreporter cells into a portable device to assess bioavailable cadmium levels in environmental samples which will provide a rapid and practical field detection technique.


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Environmental pollution particularly at very low concentrations is very difficult to remove from contaminated media. Adsorption by means of relatively inexpensive natural adsorbents such as zeolites can be considered as a cost effective alternative treatment of such contaminated streams. The unique chemical and structural characteristics of natural zeolites made them potential materials for a multitude of environmental applications where materials are needed for effective binding, adsorbing, and filtering. ...
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Environmental heavy metal contamination in many regions of the world is a serious problem of ecological health. Fast and constant monitoring of their levels is significant for both preventing their accumulation and taking an immediate action for removal. As an alternative approach to standard laboratory techniques, various biosensor systems for detection of heavy metals have been proposed. Bacterial biosensors hold great promise for in-field detection of heavy metals. In this study, two different whole cell...
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Increasing concern about the pollution of environment by inorganic and organic chemicals arising from naturally occurring ecological events and industrial processes has created a need for the search of new techniques in the removal of these contaminants. One of the natural material that can be used in such processes is clay. Clay minerals have large surface areas and high cation exchange capacities which enables them to be modified by cationic surfactants. The material prepared, often called as ءorganoclay̕...
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Ünlü, Kahraman; Yurteri, C (Wiley, 1999-12-01)
Pollution of ground water caused by excessive and uncontrolled use of nitrogen fertilizer is worrying. A recent example of such pollution has been observed in an agricultural basin in the province of Nevsehir, Turkey, where up to 900 kg ha(-1) nitrogen fertilizer is used for growing potatoes in sandy soils under irrigation. Using nitrogen fertilizer in amounts that guarantee large yields without polluting ground water is essential. We present results of field experiments and numerical simulations involving ...
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The assessment of volatile organic compounds (VOCs) has become an important field of interest in atmospheric pollution. This study quantifies and characterizes the ambient levels and spatial distribution of VOCs in urban and rural areas of Balıkesir. In addition, for the city drinking water dam excess flux from the traffic estimation was done. For these assessments passive sampling of VOCs performed at approximately 50 locations in and around the city of Balıkesir and analyzed with GC-FID system. Tenax TA w...
Citation Formats
E. Elcin and H. A. Öktem, “Inorganic Cadmium Detection Using a Fluorescent Whole-Cell Bacterial Bioreporter,” ANALYTICAL LETTERS, pp. 2715–2733, 2020, Accessed: 00, 2020. [Online]. Available: