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. 2008 Jan;1(1):53-61.
doi: 10.1111/j.1751-7915.2007.00006.x.

Activity and viability of polycyclic aromatic hydrocarbon-degrading Sphingomonas sp. LB126 in a DC-electrical field typical for electrobioremediation measures

Lei Shi  1 , Susann Müller, Norbert Loffhagen, Hauke Harms, Lukas Y Wick
Affiliations

Activity and viability of polycyclic aromatic hydrocarbon-degrading Sphingomonas sp. LB126 in a DC-electrical field typical for electrobioremediation measures

Lei Shi et al. Microb Biotechnol. 2008 Jan.

Abstract

There has been growing interest in employing electro-bioremediation, a hybrid technology of bioremediation and electrokinetics for the treatment of contaminated soil. Knowledge however on the effect of weak electrokinetic conditions on the activity and viability of pollutant-degrading microorganisms is scarce. Here we present data about the influence of direct current (DC) on the membrane integrity, adenosine triphosphate (ATP) pools, physico-chemical cell surface properties, degradation kinetics and culturability of fluorene-degrading Sphingomonas sp. LB126. Flow cytometry was applied to quantify the uptake of propidium iodide (PI) and the membrane potential-related fluorescence intensities (MPRFI) of individual cells within a population. Adenosine tri-phosphate contents and fluorene biodegradation rates of bulk cultures were determined and expressed on a per cell basis. The cells' surface hydrophobicity and electric charge were assessed by contact angle and zeta potential measurements respectively. Relative to the control, DC-exposed cells exhibited up to 60% elevated intracellular ATP levels and yet remained unaffected on all other levels of cellular integrity and functionality tested. Our data suggest that direct current (X=1 V cm(-1); J=10.2 mA cm(-2)) as typically used for electrobioremediation measures has no negative effect on the activity of the polycyclic aromatic hydrocarbon (PAH)-degrading soil microorganism, thereby filling a serious gap of the current knowledge of the electrobioremediation methodology.

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Figures

Figure 1
Figure 1
Time‐dependent fractions of total (Nt; A) and PI‐stained (PIt, B) Sphingomonas sp. LB126 cells in the presence (filled circles, 1 V cm−1) and absence (open circles) of DC. Data are normalized relative to initial conditions (Ninitial; PIinitial).
Figure 2
Figure 2
Normalized fractions of intracellular ATP contents (A) and cell membrane potential‐related fluorescence intensity (MPRFI) (B) in the presence (filled circles, 1 V cm−1) and absence (open circles) of DC. Data are normalized relative to initial values.
Figure 3
Figure 3
Representation of the apparent fluorene biodegradation rates of Sphingomonas sp. LB126 relative to measured dissolved bulk fluorene concentrations in the presence (filled circles, 1 Vcm−1) and absence (open circles) of DC. Fluorene biodegradation rates in the presence of DC were corrected for apparent abiotic (electrochemical) losses as described in Experimental procedures.
Figure 4
Figure 4
Time‐dependent physicochemical cell surface properties of Sphingomonas sp. LB126 exposed to DC. (A) and (B) reflect the water contact (θw) and the zeta potential (ζ), respectively, in the presence (filled circles, 1 V cm−1) or absence (open circles) of DC.
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References

    1. Aronsson K., Ronner U., Borch E. Inactivation of Escherichia coliListeria innocua and Saccharomyces cerevisiae in relation to membrane permeabilization and subsequent leakage of intracellular compounds due to pulsed electric field processing. Int J Food Microbiol. 2005;99:19–32. - PubMed
    1. Bosma T.N.P., Middeldorp P.J.M., Schraa G., Zehnder A.J.B. Mass transfer limitation of biotransformation: quantifying bioavailability. Environ Sci Technol. 1997;31:248–252.
    1. Chen C.Y., Nace G.W., Irwin P.L. A 6 × 6 drop plate method for simultaneous colony counting and MPN enumeration of Campylobacter jejuniListeria monocytogenes, and Escherichia coli. J Microbiol Methods. 2003;55:475–479. - PubMed
    1. Comas J., VivesRego J. Assessment of the effects of gramicidin, formaldehyde, and surfactants on Escherichia coli by flow cytometry using nucleic acid and membrane potential dyes. Cytometry. 1997;29:58–64. - PubMed
    1. Elez‐Martinez P., Escola‐Hernandez J., Soliva‐Fortuny R.C., Martin‐Belloso O. Inactivation of Saccharomyces cerevisiae suspended in orange juice using high‐intensity pulsed electric fields. J Food Prot. 2004;67:2596–2602. - PubMed

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