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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

Cultures carried out at different initial pH: (a) pH and C source consumption; (b) growth and pyoverdine production.
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biosensors-03-00385-f003: Cultures carried out at different initial pH: (a) pH and C source consumption; (b) growth and pyoverdine production.

Mentions: Once the optimal carbon source and temperature for growth and siderophore production were established, the influence of the initial pH was evaluated. The biomass growth, pH values, C source consumption and pyoverdine biosynthesis of the cultures started from the M78 media buffered at different pH are reported in Figure 3. This test showed that the higher the initial pH, the faster the growth of the microorganism during the exponential phase and, consequently, the earlier the stationary phase is reached. The behavior of pH and carbon source consumption was related to the growth curve of the cultures. The stationary phase was achieved when the pH was about 8.0, and the succinic acid was almost depleted (concentration lower than 0.5 g/L) after 20, 30 and 40 h for pH 7.5, 7.0 and 6.5, respectively. This observation further confirms that the drop in OD620 recorded during the stationary phase is probably related only to a C source limitation (succinic acid concentration <0.5 g/L): the microorganism seems to grow faster at basic pH, as can be deduced from the carbon source consumptions and OD620 trends.


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)

Cultures carried out at different initial pH: (a) pH and C source consumption; (b) growth and pyoverdine production.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

biosensors-03-00385-f003: Cultures carried out at different initial pH: (a) pH and C source consumption; (b) growth and pyoverdine production.
Mentions: Once the optimal carbon source and temperature for growth and siderophore production were established, the influence of the initial pH was evaluated. The biomass growth, pH values, C source consumption and pyoverdine biosynthesis of the cultures started from the M78 media buffered at different pH are reported in Figure 3. This test showed that the higher the initial pH, the faster the growth of the microorganism during the exponential phase and, consequently, the earlier the stationary phase is reached. The behavior of pH and carbon source consumption was related to the growth curve of the cultures. The stationary phase was achieved when the pH was about 8.0, and the succinic acid was almost depleted (concentration lower than 0.5 g/L) after 20, 30 and 40 h for pH 7.5, 7.0 and 6.5, respectively. This observation further confirms that the drop in OD620 recorded during the stationary phase is probably related only to a C source limitation (succinic acid concentration <0.5 g/L): the microorganism seems to grow faster at basic pH, as can be deduced from the carbon source consumptions and OD620 trends.

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