Quantification of small-scale variation in the size and composition of phenanthrene-degrader populations and PAH contaminants in traffic-impacted topsoil

TY - JOUR

T1 - Quantification of small-scale variation in the size and composition of phenanthrene-degrader populations and PAH contaminants in traffic-impacted topsoil

AU - Johnsen, Anders R

AU - Styrishave, Bjarne

AU - Aamand, Jens

N1 - © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

PY - 2014/4

Y1 - 2014/4

N2 - Small-scale colocalisation of microbial polycyclic aromatic hydrocarbon (PAH) degraders and PAHs in contaminated soil is a prerequisite for efficient biodegradation of the PAHs. We therefore tested the hypothesis that phenanthrene-degrading bacteria are colocalised with PAHs at the millimetre-to-centimetre-scale. Microbial populations and PAH concentrations were determined for 40-mg samples from a 112-mm transect of a traffic-impacted topsoil. The spatial distribution of cultivable phenanthrene degraders (0.3 × 10(5) -7.2 × 10(5) cells g(-1) ) mirrored neither the distribution of PAHs, nor the distribution of the total cultivable heterotrophic populations. Quantitative real-time PCR (qPCR) analysis of PAH dioxygenase genes (2 × 10(6) -4 × 10(6) cells g(-1) ) from a second transect showed distributions similar to the cultivable phenanthrene degraders, but at a 20-fold higher level. The omnipresence of high densities of PAH degraders at the millimetre scale indicate that PAH persistence may not be caused by local lack of degrader cells. To the best of our knowledge, this is the first time that either MPN of pollutant degraders, qPCR of functional genes, CFU of heterotrophic micro-organisms, or the content of PAHs have been determined with such high spatial resolution.

AB - Small-scale colocalisation of microbial polycyclic aromatic hydrocarbon (PAH) degraders and PAHs in contaminated soil is a prerequisite for efficient biodegradation of the PAHs. We therefore tested the hypothesis that phenanthrene-degrading bacteria are colocalised with PAHs at the millimetre-to-centimetre-scale. Microbial populations and PAH concentrations were determined for 40-mg samples from a 112-mm transect of a traffic-impacted topsoil. The spatial distribution of cultivable phenanthrene degraders (0.3 × 10(5) -7.2 × 10(5) cells g(-1) ) mirrored neither the distribution of PAHs, nor the distribution of the total cultivable heterotrophic populations. Quantitative real-time PCR (qPCR) analysis of PAH dioxygenase genes (2 × 10(6) -4 × 10(6) cells g(-1) ) from a second transect showed distributions similar to the cultivable phenanthrene degraders, but at a 20-fold higher level. The omnipresence of high densities of PAH degraders at the millimetre scale indicate that PAH persistence may not be caused by local lack of degrader cells. To the best of our knowledge, this is the first time that either MPN of pollutant degraders, qPCR of functional genes, CFU of heterotrophic micro-organisms, or the content of PAHs have been determined with such high spatial resolution.

U2 - 10.1111/1574-6941.12272

DO - 10.1111/1574-6941.12272

M3 - Journal article

C2 - 24344982

SN - 0168-6496

VL - 88

SP - 84

EP - 93

JO - F E M S Microbiology Ecology

JF - F E M S Microbiology Ecology

IS - 1

ER -