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Opening Study on the Development of a New Biosensor for Metal Toxicity Based on Pseudomonas fluorescens Pyoverdine.

Chiadò A, Varani L, Bosco F, Marmo L - Biosensors (Basel) (2013)

Bottom Line: To date, different kinds of biosensing elements have been used effectively for environmental monitoring.Each of these variables has been shown to influence the synthesis of siderophore: for instance, the lower the temperature, the higher the production of pyoverdine.Moreover, the concentration of pyoverdine produced in the presence of metals has been compared with the maximum allowable concentrations indicated in international regulations (e.g., 98/83/EC), and a correlation that could be useful to build a colorimetric biosensor has been observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129, Torino, Italy. alessandro.chiado@polito.it.

ABSTRACT
To date, different kinds of biosensing elements have been used effectively for environmental monitoring. Microbial cells seem to be well-suited for this task: they are cheap, adaptable to variable field conditions and give a measurable response to a broad number of chemicals. Among different pollutants, heavy metals are still a major problem for the environment. A reasonable starting point for the selection of a biorecognition element to develop a biosensor for metals could be that of a microorganism that exhibits good mechanisms to cope with metals. Pseudomonads are characterized by the secretion of siderophores (e.g., pyoverdine), low-molecular weight compounds that chelate Fe3+ during iron starvation. Pyoverdine is easily detected by colorimetric assay, and it is suitable for simple online measurements. In this work, in order to evaluate pyoverdine as a biorecognition element for metal detection, the influence of metal ions (Fe3+, Cu2+, Zn2+), but also of temperature, pH and nutrients, on microbial growth and pyoverdine regulation has been studied in P. fluorescens. Each of these variables has been shown to influence the synthesis of siderophore: for instance, the lower the temperature, the higher the production of pyoverdine. Moreover, the concentration of pyoverdine produced in the presence of metals has been compared with the maximum allowable concentrations indicated in international regulations (e.g., 98/83/EC), and a correlation that could be useful to build a colorimetric biosensor has been observed.

No MeSH data available.


Related in: MedlinePlus

Minimum inhibitory concentrations (MICs) of Fe3+, Cu2+ and Zn2+ obtained on agar plates.
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biosensors-03-00385-f004: Minimum inhibitory concentrations (MICs) of Fe3+, Cu2+ and Zn2+ obtained on agar plates.

Mentions: The interactions between the metals (Fe3+, Cu2+ and Zn2+) and P. fluorescens were then investigated applying a modified Kirby-Bauer test [24]. The first step was to determine the minimum inhibitory concentration (MIC), which is defined as the lowest metal concentration for which the growth is inhibited after overnight incubation [26] (Figure 4). The area of the inhibition halo measured applying different metal concentrations allowed the values of the MICs to be calculated for CuSO4, ZnSO4 and Fe2[SO4]3, and these resulted in 46.30, 54.40 and 74.11 mM, respectively. Two different salts were tested for Fe3+ to evaluate the counter-ion effect: SO42− was less toxic than Cl− [24].


Opening Study on the Development of a New Biosensor for Metal Toxicity Based on Pseudomonas fluorescens Pyoverdine.

Chiadò A, Varani L, Bosco F, Marmo L - Biosensors (Basel) (2013)

Minimum inhibitory concentrations (MICs) of Fe3+, Cu2+ and Zn2+ obtained on agar plates.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263567&req=5

biosensors-03-00385-f004: Minimum inhibitory concentrations (MICs) of Fe3+, Cu2+ and Zn2+ obtained on agar plates.
Mentions: The interactions between the metals (Fe3+, Cu2+ and Zn2+) and P. fluorescens were then investigated applying a modified Kirby-Bauer test [24]. The first step was to determine the minimum inhibitory concentration (MIC), which is defined as the lowest metal concentration for which the growth is inhibited after overnight incubation [26] (Figure 4). The area of the inhibition halo measured applying different metal concentrations allowed the values of the MICs to be calculated for CuSO4, ZnSO4 and Fe2[SO4]3, and these resulted in 46.30, 54.40 and 74.11 mM, respectively. Two different salts were tested for Fe3+ to evaluate the counter-ion effect: SO42− was less toxic than Cl− [24].

Bottom Line: To date, different kinds of biosensing elements have been used effectively for environmental monitoring.Each of these variables has been shown to influence the synthesis of siderophore: for instance, the lower the temperature, the higher the production of pyoverdine.Moreover, the concentration of pyoverdine produced in the presence of metals has been compared with the maximum allowable concentrations indicated in international regulations (e.g., 98/83/EC), and a correlation that could be useful to build a colorimetric biosensor has been observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129, Torino, Italy. alessandro.chiado@polito.it.

ABSTRACT
To date, different kinds of biosensing elements have been used effectively for environmental monitoring. Microbial cells seem to be well-suited for this task: they are cheap, adaptable to variable field conditions and give a measurable response to a broad number of chemicals. Among different pollutants, heavy metals are still a major problem for the environment. A reasonable starting point for the selection of a biorecognition element to develop a biosensor for metals could be that of a microorganism that exhibits good mechanisms to cope with metals. Pseudomonads are characterized by the secretion of siderophores (e.g., pyoverdine), low-molecular weight compounds that chelate Fe3+ during iron starvation. Pyoverdine is easily detected by colorimetric assay, and it is suitable for simple online measurements. In this work, in order to evaluate pyoverdine as a biorecognition element for metal detection, the influence of metal ions (Fe3+, Cu2+, Zn2+), but also of temperature, pH and nutrients, on microbial growth and pyoverdine regulation has been studied in P. fluorescens. Each of these variables has been shown to influence the synthesis of siderophore: for instance, the lower the temperature, the higher the production of pyoverdine. Moreover, the concentration of pyoverdine produced in the presence of metals has been compared with the maximum allowable concentrations indicated in international regulations (e.g., 98/83/EC), and a correlation that could be useful to build a colorimetric biosensor has been observed.

No MeSH data available.


Related in: MedlinePlus