Quantification of the biocontrol agent Pseudomonas fluorescens Pf153 in soil using a quantitative competitive PCR assay unaffected by variability in cell lysis- and DNA-extraction efficiency

2007 ◽  
Vol 39 (7) ◽  
pp. 1609-1619 ◽  
Author(s):  
Davide Gobbin ◽  
Fabio Rezzonico ◽  
Cesare Gessler
Keyword(s):  
Pseudomonas Fluorescens ◽  
Dna Extraction ◽  
Biocontrol Agent ◽  
Extraction Efficiency ◽  
Cell Lysis ◽  
Competitive Pcr ◽  
Pcr Assay

scholarly journals Effect of Stress on the Ability of a phlA-Based Quantitative Competitive PCR Assay To Monitor Biocontrol Strain Pseudomonas fluorescens CHA0

2003 ◽  
Vol 69 (1) ◽  
pp. 686-690 ◽  
Author(s):  
Fabio Rezzonico ◽  
Yvan Moënne-Loccoz ◽  
Geneviève Défago
Keyword(s):  
Pseudomonas Fluorescens ◽  
Cell Number ◽  
Total Cell ◽  
Competitive Pcr ◽  
Pcr Assay ◽  
Total Cell Number ◽  
Stressed Cells ◽  
Positive Correlations ◽  
Biocontrol Strain

ABSTRACT A quantitative competitive PCR (QC-PCR) assay targeting the phlA gene of Pseudomonas fluorescens CHA0 was developed and tested in vitro. Statistically significant, positive correlations were found between QC-PCR and both CFU and total cell number when studying cells in log or stationary phase. The correlations disappeared when considering stressed cells.

scholarly journals Microbial Photoinactivation by Visible Light Results in Limited Loss of Membrane Integrity

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 341
Author(s):  
Katharina Hoenes ◽  
Richard Bauer ◽  
Barbara Spellerberg ◽  
Martin Hessling
Keyword(s):  
Visible Light ◽  
Pseudomonas Fluorescens ◽  
Bacterial Cell ◽  
Bacterial Species ◽  
Membrane Integrity ◽  
Cell Lysis ◽  
Microbial Inactivation ◽  
Bacterial Cells ◽  
Resistance Development ◽  
Transmission Electron

Interest in visible light irradiation as a microbial inactivation method has widely increased due to multiple possible applications. Resistance development is considered unlikely, because of the multi-target mechanism, based on the induction of reactive oxygen species by wavelength specific photosensitizers. However, the affected targets are still not completely identified. We investigated membrane integrity with the fluorescence staining kit LIVE/DEAD® BacLight™ on a Gram positive and a Gram negative bacterial species, irradiating Staphylococcus carnosus and Pseudomonas fluorescens with 405 nm and 450 nm. To exclude the generation of viable but nonculturable (VBNC) bacterial cells, we applied an ATP test, measuring the loss of vitality. Pronounced uptake of propidium iodide was only observed in Pseudomonas fluorescens at 405 nm. Transmission electron micrographs revealed no obvious differences between irradiated samples and controls, especially no indication of an increased bacterial cell lysis could be observed. Based on our results and previous literature, we suggest that visible light photoinactivation does not lead to rapid bacterial cell lysis or disruption. However, functional loss of membrane integrity due to depolarization or inactivation of membrane proteins may occur. Decomposition of the bacterial envelope following cell death might be responsible for observations of intracellular component leakage.

scholarly journals Determining the optimal method for DNA isolation from fruit jams

2018 ◽  
Vol 36 (No. 2) ◽  
pp. 126-132
Author(s):  
Sovová Tereza ◽  
Křížová Barbora ◽  
Ovesná Jaroslava
Keyword(s):  
Dna Extraction ◽  
Dna Isolation ◽  
Extraction Methods ◽  
Food Samples ◽  
Pcr Analysis ◽  
Uv Spectrophotometry ◽  
Pcr Assay ◽  
Optimal Method ◽  
Ctab Method ◽  
Dna Extraction Methods

DNA extraction is a crucial step in PCR analysis especially when analysing food samples that can be degraded and can potentially contain PCR-inhibiting substances. In this study, we compared the suitability of three DNA extraction methods – two kits: DNeasy<sup>®</sup> Plant Mini Kit and NucleoSpin<sup>®</sup> Food, and the CTAB method – for DNA extraction from commercial fruit jams. Fourteen jams with different contents of fruit, sugar and other additives were extracted in triplicate using the above-mentioned methods directly and after a washing step. The concentration and optical density were analysed using UV spectrophotometry and the amplifiability of the obtained DNA was evaluated using a PCR assay targeting a sequence coding for chloroplast tRNA-Leu. Samples isolated using the NucleoSpin<sup>®</sup> Food kit contained non-amplifiable DNA in eight cases, and samples isolated using the CTAB method could not be quantified. The DNeasy<sup>®</sup> Plant Mini Kit thus proved to be the most suitable method, since well-amplifiable DNA was obtained for all the analysed samples.

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