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 ar omatic 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 t he culture broth of cells grown in mineral salts (MS) medium with succ inate and yeast extract, affected the extent of PAH degradation by the bacterial cells and prevented flocculation of PAHs in an aqueous susp ension. A washed suspension of P. marginalis cells also prevented floc culation of PAH suspensions and emulsified liquid hydrocarbons. Incuba tion of the factor and the factor-producing strain in the presence of different PAHs resulted in gradual increase of turbidity of the PAH di spersions. 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 a lso have application in bioremediation.