Taxonomic identification, phenanthrene uptake activity, and membrane lipid alterations of the PAH degrading Arthrobacter sp strain Sphe3

This report describes phenanthrene uptake as well as the effect of phenanthrene on the membrane phospholipid and fatty acid composition in a newly isolated bacterial strain, Sphe3, that we taxonomically identified as Arthrobacter sp. Strain Sphe3 is able to utilize phenanthrene as a carbon source at high rates and appears to internalize phenanthrene with two mechanisms: a passive diffusion when cells are grown on glucose, and an inducible active transport system when cells are grown on phenanthrene as a sole carbon source. Active transport followed Michaelis-Menten kinetics, and it was amenable to inhibition by 2,4-dinitrophenol and sodium azide. Evidence provided here indicates that apart from inducing an active PAH uptake, the presence of phenanthrene elicits significant changes in membrane fluidity.