Pseudomonas aeruginosa NP2 as a Model for Rhamnolipid Production in Bioreactor Systems

Rhamnolipids are among the best known biosurfactants and have been proven to be very promising in enhanced oil recovery, cosmetics, food and pharmaceutics. In this research, rhamnolipid production by Pseudomonas aeruginosa NP2 in a bioreactor
has been investigated. This study shows that the Pseudomonas aeruginosa NP2 is able to produce high quantities of rhamnolipid during 2.5 L batch bioreactor cultivations with sunflower oil as sole carbon source. The results showed that the maximum rhamnolipid concentration obtained was 13.5 g/L after 80 h of cultivation. The results also showed that the rhamnolipid production started at exponential growth phase and continued during the stationary phase. Two rhamnolipids, RL1 and RL, produced by the microorganism, were confirmed by TLC and HPLC analysis. Finally, the produced rhamnolipid showed good surface activity because it is able to reduce the surface tension from 68 mN/m to 26 mN/m. Thus, Pseudomonas aeruginosa NP2 could be an appropriate model for rhamnolipid production in pilot plant bioreactor systems.