Fig. 1

Effect of porous matrix on growth of P. veronii miniTn5::gfp with toluene. a P. veronii (Pve, strain 3381) growth in liquid suspension or artificial porous matrix. b Growth in contaminated (Jonction) and three natural non-sterile soils, in presence of externally added toluene. Data points show the mean number of colony forming units (CFU) ml−1 (for liquid suspension) or g−1 (for porous material) from independent biological triplicates, plotted on a logaritmic scale. Error bars represent calculated standard deviations from the mean. Identity of P. veronii colonies on MM plates with toluene vapor verified by their GFP fluorescence