THE EFFECT OF IMMOBILIZATION ON RHAMNOLIPID PRODUCTION BY PSEUDOMONAS-FLUORESCENS

Pseudomonas fluorescens in free suspension and immobilized to a commer cially available biosupport (Biofix) and a biosorbent (Drizit), were u sed as bioremediation agents in an aqueous system with petrol (Slovene diesel) as the carbon source. Analysis of cellular growth and estimat ion of rhamnolipid production was carried out on the free suspension o f the free and immobilized systems over 5 d. An increase in growth and rhamnolipid production was seen in the immobilized systems in compari son to the free system. EDTA was shown to be an inhibitor of rhamnolip id production. Its addition to the aqueous suspensions of all systems resulted in a fall in production of the surface-active agent in all ca ses, with no corresponding decrease in growth. This indicates the bact eria can rely on contact between the cell and the oil droplet for hydr ocarbon transport into the cell. The data from this study indicated th at immobilization resulted in a combination of increased contact betwe en cell and hydrocarbon droplets and enhanced levels of rhamnolipid pr oduction.