Limits...
Bacterial responses and interactions with plants during rhizoremediation.

Segura A, Rodríguez-Conde S, Ramos C, Ramos JL - Microb Biotechnol (2009)

Bottom Line: Rhizoremediation, the use of rhizospheric microorganisms in the bioremediation of contaminants, is the biotechnological approach that we explore in this minireview.We focus our attention on bacterial interactions with the plant surface, responses towards root exudates, and how plants and microbes communicate.We analyse certain strategies that may improve rhizoremediation, including the utilization of endophytes, and finally we discuss several rhizoremediation strategies that have opened ways to improve biodegradation.

View Article: PubMed Central - PubMed

Affiliation: Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Department of Environmental Microbiology, Professor Albareda 1, E-18008 Granada, Spain. ana.segura@eez.csic.es

Show MeSH

Related in: MedlinePlus

Light emission of a luxAB‐tagged P. putida KT2440 derivative (P. putida strain S1B1) colonizing the root system of Zea mays. A sterile maize seed (*) was coated with mid‐log phase grown cells of this strain and germinated in vermiculite. Bioluminescence in the root system of the developing maize plant was detected 15 days after planting by photon counting using a CCD camera. Dark‐field‐exposure (30 s) was processed with Adobe Photoshop software. The relative intensity of light emission is indicated by the colour scale.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3815906&req=5

f1: Light emission of a luxAB‐tagged P. putida KT2440 derivative (P. putida strain S1B1) colonizing the root system of Zea mays. A sterile maize seed (*) was coated with mid‐log phase grown cells of this strain and germinated in vermiculite. Bioluminescence in the root system of the developing maize plant was detected 15 days after planting by photon counting using a CCD camera. Dark‐field‐exposure (30 s) was processed with Adobe Photoshop software. The relative intensity of light emission is indicated by the colour scale.

Mentions: Successful rhizosphere colonization depends not only on interactions between the plants and the microorganisms of interest, but also on interactions with other rhizospheric microorganisms and the environment. Molecular techniques, such as denaturing or temperature gradient gel electrophoresis have allowed researchers to follow the modifications in bacterial communities after environmental perturbations, including the introduction of plants or biodegradative bacteria, changes in temperature, or the addition of contaminants (Smit et al., 2001; Kent and Triplett, 2002; de Cárcer et al., 2007; Kielak et al., 2008). Several techniques to follow seed and root colonization by bacteria have been developed during the last 15 years, which mainly include in situ hybridization assays using fluorescent probes and the visualization of bacteria that carry the luxAB genes encoding bacterial luciferase (Fig. 1), the green fluorescent protein, or another reporter gene (Tombolini et al., 1999; Broek et al., 1998; Ramos et al., 2000a,b; 2001). These techniques have been used to illustrate that introduced microorganisms are often unable to compete with indigenous microorganisms or are unable to establish high numbers in the rhizosphere (Rattray et al., 1995; Lübeck et al., 2000). Some bacteria have developed strategies to out‐compete other microorganisms by delivering toxins, using extremely efficient nutrient utilization systems, or by physical exclusion (Lugtenberg et al., 1991). However, many other factors involved in successful colonization, under non‐sterile conditions, remain unknown.


Bacterial responses and interactions with plants during rhizoremediation.

Segura A, Rodríguez-Conde S, Ramos C, Ramos JL - Microb Biotechnol (2009)

Light emission of a luxAB‐tagged P. putida KT2440 derivative (P. putida strain S1B1) colonizing the root system of Zea mays. A sterile maize seed (*) was coated with mid‐log phase grown cells of this strain and germinated in vermiculite. Bioluminescence in the root system of the developing maize plant was detected 15 days after planting by photon counting using a CCD camera. Dark‐field‐exposure (30 s) was processed with Adobe Photoshop software. The relative intensity of light emission is indicated by the colour scale.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3815906&req=5

f1: Light emission of a luxAB‐tagged P. putida KT2440 derivative (P. putida strain S1B1) colonizing the root system of Zea mays. A sterile maize seed (*) was coated with mid‐log phase grown cells of this strain and germinated in vermiculite. Bioluminescence in the root system of the developing maize plant was detected 15 days after planting by photon counting using a CCD camera. Dark‐field‐exposure (30 s) was processed with Adobe Photoshop software. The relative intensity of light emission is indicated by the colour scale.
Mentions: Successful rhizosphere colonization depends not only on interactions between the plants and the microorganisms of interest, but also on interactions with other rhizospheric microorganisms and the environment. Molecular techniques, such as denaturing or temperature gradient gel electrophoresis have allowed researchers to follow the modifications in bacterial communities after environmental perturbations, including the introduction of plants or biodegradative bacteria, changes in temperature, or the addition of contaminants (Smit et al., 2001; Kent and Triplett, 2002; de Cárcer et al., 2007; Kielak et al., 2008). Several techniques to follow seed and root colonization by bacteria have been developed during the last 15 years, which mainly include in situ hybridization assays using fluorescent probes and the visualization of bacteria that carry the luxAB genes encoding bacterial luciferase (Fig. 1), the green fluorescent protein, or another reporter gene (Tombolini et al., 1999; Broek et al., 1998; Ramos et al., 2000a,b; 2001). These techniques have been used to illustrate that introduced microorganisms are often unable to compete with indigenous microorganisms or are unable to establish high numbers in the rhizosphere (Rattray et al., 1995; Lübeck et al., 2000). Some bacteria have developed strategies to out‐compete other microorganisms by delivering toxins, using extremely efficient nutrient utilization systems, or by physical exclusion (Lugtenberg et al., 1991). However, many other factors involved in successful colonization, under non‐sterile conditions, remain unknown.

Bottom Line: Rhizoremediation, the use of rhizospheric microorganisms in the bioremediation of contaminants, is the biotechnological approach that we explore in this minireview.We focus our attention on bacterial interactions with the plant surface, responses towards root exudates, and how plants and microbes communicate.We analyse certain strategies that may improve rhizoremediation, including the utilization of endophytes, and finally we discuss several rhizoremediation strategies that have opened ways to improve biodegradation.

View Article: PubMed Central - PubMed

Affiliation: Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Department of Environmental Microbiology, Professor Albareda 1, E-18008 Granada, Spain. ana.segura@eez.csic.es

Show MeSH
Related in: MedlinePlus