Natural Electrotransformation of Lightning-Competent Pseudomonas sp. Strain N3 in Artificial Soil Microcosms

Abstract

The lightning-competent Pseudomonas sp. strain N3, recently isolated from soil, has been used to study the extent of natural electrotransformation (NET) or lightning transformation as a horizontal gene transfer mechanism in soil. The variation of electrical fields applied to the soil with a laboratory-scale lightning system provides an estimate of the volume of soil affected by NET. Based on the range of the electric field that induces NET of Pseudomonas strain N3, the volume of soil, where NET could occur, ranges from 2 to 950 m(3) per lightning strike. The influence of DNA parameters (amount, size, and purity) and DNA soil residence time were also investigated. NET frequencies (electrotransformants/recipient cells) ranged from 10(-8) for cell lysate after 1 day of residence in soil to 4 x 10(-7) with a purified plasmid added immediately before the lightning. The electrical field gradient (in kilovolts per cm) also played a role as NET frequencies ranging from 1 x 10(-5) at 2.3 kV/cm to 1.7 x 10(-4) at 6.5 kV/cm.

Antimicrobial Resistance in the Food Chain: A Review

“…Competence in some bacterial species such as E. coli can be induced in vitro by chemical or physical conditions such as the presence of CaCl 2 , EDTA, temperature shifts, electro-shocks or lightening [53,54,55]. It can be hypothesized that several minimal processing methods likewise could induce bacterial competence.…”

Food Safety Engineering: An Emergent Perspective

“…The protective action against DNAases of individual food components such as arginine, polyamines, and biogenic amines is shown by in vitro experiments [190]; the protective action of the complex food matrix in sausages is reported by Straub et al [178]. Competence (the ability to take up DNA from their environment) of bacterial species such as E. coli can be induced by chemical or physical conditions, such as presence of salts, temperature shifts, electro-shocks [30,31,50]. The development of competence and natural transformation has been shown for Bacillus subtilis in milk [99,202].…”

Magnetic nanoparticle DNA labeling for individual bacterial cell detection and recovery

“…Plasmid DNA integration was carried out by electroporation, a transformation process in which bacteria are subjected to high-voltage electrical pulses to create temporary pores in the bacterial envelopes for a passive entry of DNA, in contrast to genetically-encoded natural transformation. Efficient and commonly used in microbiology, (Drury, 1996;Society et al, 1988) electro-transformation is also relevant as a mechanism susceptible to promote gene transfer under natural conditions when soil is hit by lightning discharges (Cérémonie et al, 2006b(Cérémonie et al, , 2004. Plasmid penetration and cell attraction could only be monitored at the same time as there was no possibility to demonstrate if the plasmid DNA had been successfully taken up by cells.…”