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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

(a) Biomass growth in cultures supplemented with FeCl3. (b) Pyoverdine production (OD400) in cultures supplemented with FeCl3.
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biosensors-03-00385-f005: (a) Biomass growth in cultures supplemented with FeCl3. (b) Pyoverdine production (OD400) in cultures supplemented with FeCl3.

Mentions: The microorganism was able to grow at each tested iron concentration, and no toxic effects were observed in the 0–6.25 mM range of Fe3+, unlike the results by Workentine et al. [35] (Table 1). Furthermore, when the concentration of ferric ion in solution was increased, faster growth and higher maximum OD620 values were recorded, compared to the control (0 mM FeCl3) (Figure 5(a)): the presence of a low concentration of metals could be an advantage during microbial fermentation and, in particular, for the growth of P. fluorescens [14,23]. Moreover, the pyoverdine production chiefly depends on the Fe3+: if the concentration is above a critical value (non-limiting iron or critical iron concentration for pyoverdine production, or CICP), the siderophore synthesis is repressed by the microorganism. During this test, siderophore was only produced in the control flask (0 mM Fe3+) and not by the other cultures (Figure 5(b)), confirming that the CICP is lower than 0.1 mM, in agreement with the results of other authors [23].


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)

(a) Biomass growth in cultures supplemented with FeCl3. (b) Pyoverdine production (OD400) in cultures supplemented with FeCl3.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

biosensors-03-00385-f005: (a) Biomass growth in cultures supplemented with FeCl3. (b) Pyoverdine production (OD400) in cultures supplemented with FeCl3.
Mentions: The microorganism was able to grow at each tested iron concentration, and no toxic effects were observed in the 0–6.25 mM range of Fe3+, unlike the results by Workentine et al. [35] (Table 1). Furthermore, when the concentration of ferric ion in solution was increased, faster growth and higher maximum OD620 values were recorded, compared to the control (0 mM FeCl3) (Figure 5(a)): the presence of a low concentration of metals could be an advantage during microbial fermentation and, in particular, for the growth of P. fluorescens [14,23]. Moreover, the pyoverdine production chiefly depends on the Fe3+: if the concentration is above a critical value (non-limiting iron or critical iron concentration for pyoverdine production, or CICP), the siderophore synthesis is repressed by the microorganism. During this test, siderophore was only produced in the control flask (0 mM Fe3+) and not by the other cultures (Figure 5(b)), confirming that the CICP is lower than 0.1 mM, in agreement with the results of other authors [23].

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