Gnotobiotic System for Studying Rhizosphere Colonization by Plant Growth-Promoting<i>Pseudomonas</i>Bacteria Gnotobiotic System for Studying Rhizosphere

Simons, Marco; Bij, Arjan J. van der; Brand, I.; Weger, Letty A. de; Wijffelman, C. A.; Lugtenberg, Ben

doi:10.1094/mpmi-9-0600

Cited by 361 publications

(288 citation statements)

References 0 publications

Supporting

Mentioning

268

Contrasting

Unclassified

Order By: Relevance

“…A quartz sand jar experimental set up as described by Simons et al (1996) was used to evaluate the effectiveness of encapsulated PGPB on the lettuce growth under gnotobiotic conditions. Briefly, free cells (1 ml) of B. subtilis CC-pg104 (1 Â 10 8 CFU) and 100 mg of beads containing B. subtilis CC-pg104 were inoculated separately into glass jars with quartz sand (quadruplets) planted with three pre-germinated (24 h) lettuce seedlings which was trimmed after 5 days to retain a single plant.…”

Section: Evaluation Of Plant Growth and Root Colonization By Bead Entmentioning

confidence: 99%

Encapsulation of plant growth‐promoting bacteria in alginate beads enriched with humic acid

Young¹,

Rekha²,

Lai³

et al. 2006

Biotech & Bioengineering

154

View full text Add to dashboard Cite

The key to achieving successful, reproducible results following the introduction of beneficial microbes into soil relies on the survival rate of the inoculated bacteria in a heterogeneous soil environment and hence an improved encapsulation method was developed. Owing to the constraints associated with the inoculum formulation, in this study, encapsulation of a plant growth promoting bacteria (PGPB) isolate Bacillus subtilis CCpg104 was attempted with alginate by enriching the bead microenvironment with humic acid. High viability of the encapsulated bacteria was observed with minimum cell loss upon storage for 5 months. Steady and constant cell release from the bead was observed for 1 week at different pH. Encapsulated cells remained active as evidenced by their ability to solubilize calcium phosphate in vitro. Successful plant growth promotion of lettuce by the encapsulated bacteria under gnotobiotic and sterile environment was also achieved. Feasibility of this improved encapsulation technique is mainly due to the dual benefits of humic acid to microbe and plant and its chemical properties allowing an easy mixing with alginate without interfering in the formation of the alginate gel beads by cross-linking with Ca 2þ ions. Thus, the encapsulation method described in this study can be effectively used to protect the PGPB inoculum from adverse conditions of the soil for their successful establishment in the rhizosphere. ß

show abstract

Section: Evaluation Of Plant Growth and Root Colonization By Bead Entmentioning

confidence: 99%

Encapsulation of plant growth‐promoting bacteria in alginate beads enriched with humic acid

Young¹,

Rekha²,

Lai³

et al. 2006

Biotech & Bioengineering

154

View full text Add to dashboard Cite

show abstract

“…In particular, we have focused on the earliest stage of biofilm formation, that is, attachment to a surface. We have chosen to study Pseudomonas fluorescens strain WCS365, a plant-beneficial root colonizer used as a biological control agent on a variety of crops (Geels and Schippers, 1983;Simons et al, 1996), as our model organism. Here, we report the isolation and phenotypic and molecular analyses of mutants defective in the initiation of biofilm formation.…”

Section: Introductionmentioning

confidence: 99%

Initiation of biofilm formation in Pseudomonas fluorescens WCS365 proceeds via multiple, convergent signalling pathways: a genetic analysis

O’Toole

Kolter

1998

Molecular Microbiology

2,290

1,795

View full text Add to dashboard Cite

SummaryPopulations of surface-attached microorganisms comprising either single or multiple species are commonly referred to as biofilms. Using a simple assay for the initiation of biofilm formation (e.g. attachment to an abiotic surface) by Pseudomonas fluorescens strain WCS365, we have shown that: (i) P. fluorescens can form biofilms on an abiotic surface when grown on a range of nutrients; (ii) protein synthesis is required for the early events of biofilm formation; (iii) one (or more) extracytoplasmic protein plays a role in interactions with an abiotic surface; (iv) the osmolarity of the medium affects the ability of the cell to form biofilms. We have isolated transposon mutants defective for the initiation of biofilm formation, which we term surface attachment defective (sad ). Molecular analysis of the sad mutants revealed that the ClpP protein (a component of the cytoplasmic Clp protease) participates in biofilm formation in this organism. Our genetic analyses suggest that biofilm formation can proceed via multiple, convergent signalling pathways, which are regulated by various environmental signals. Finally, of the 24 sad mutants analysed in this study, only three had defects in genes of known function. This result suggests that our screen is uncovering novel aspects of bacterial physiology.

show abstract

“…Pseudomonas fluorescens F113, which was originally isolated from sugar beet rhizosphere (Shanahan et al 1992), is an excellent coloniser of several plant rhizospheres, such as those of sugar beet (Shanahan et al 1992, Delany et al 2001, tomato (Simons et al 1996), pea (Naseby and Lynch 1999), alfalfa (Villacieros et al 2003) and willow (Karlson, unpublished results). Derivatives of strain F113 with rhizoremediation ability were constructed genetically.…”

Section: Introductionmentioning

confidence: 99%

Degradation of PCB congeners by bacterial strains

Rein

Fernqvist

Mayer

et al. 2007

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

Biological in situ methods are options for the remediation of contaminated sites. An approach to quantify biodegradation by soil bacteria was developed, combining experiment with mathematical modelling. We performed in vitro assays to investigate the potential and kinetics of the wild-type degrader, Burkholderia sp. strain LB400 (expressing bph) and the genetically modified Pseudomonas fluorescens strains F113pcb and F113L::1180 (expressing bph under different promoters) to metabolise individual congeners of polychlorinated biphenyls (PCBs). Kinetics of metabolism was analysed using the Monod model.Results revealed similar patterns of degradable PCB congeners for LB400 and F113L::1180. The degree of PCB degradation was comparable for LB400 and F113L::1180, but was much lower for F113rifpcb. In additional mesocosm experiments with PCB contaminated soil, the F113 derivatives demonstrated a good survival ability in willow (Salix sp.) rhizosphere.Strain F113L::1180 in combination with willow plants is expected to degrade a large spectrum of PCB congeners in soil. The data from the experiments were used to calculate the time scale of the degradation process in a PCB-contaminated soil. The uncertainty of the model predictions due to the uncertainties of experimental removal velocities and bacterial cell density in soil was quantified.

show abstract

Gnotobiotic System for Studying Rhizosphere Colonization by Plant Growth-PromotingPseudomonasBacteria Gnotobiotic System for Studying Rhizosphere

Cited by 361 publications

References 0 publications

Encapsulation of plant growth‐promoting bacteria in alginate beads enriched with humic acid

Encapsulation of plant growth‐promoting bacteria in alginate beads enriched with humic acid

Initiation of biofilm formation in Pseudomonas fluorescens WCS365 proceeds via multiple, convergent signalling pathways: a genetic analysis

Degradation of PCB congeners by bacterial strains

Contact Info

Product

Resources

About