Involvement of a surface-active high molecular weight factor in degradation of polycyclic aromatic hydrocarbons by Pseudomonas marginalis.

A strain of Pseudomonas marginalis PD-14B, isolated from polycyclic aromatic hydrocarbon (PAH) contaminated soil, produced an extracellular surface-active factor of high molecular weight containing protein and lipopolysaccharide. A crude preparation of the factor, obtained from the culture both of cells grown in mineral salts (MS) medium with succinate and yeast extract, affected the extent of PAH degradation by the bacterial cells and prevented flocculation of PAHs in an aqueous suspension. A washed suspension of P. marginalis cells also prevented flocculation of PAH suspensions and emulsified liquid hydrocarbons. Incubation of the factor and the factor-producing strain in the presence of different PAHs resulted in gradual increase of turbidity of the PAH dispersions. The factor markedly stimulated rate and extent of turbidity generation by bacterial cells. The surface-active factor may promote infection of lettuce and other plants by this known pathogen and may also have application in bioremediation.