Biosurfactants are microbial substances which influence interfacial tension. The kinetic study was carried out for Pseudomonas aeruginosa MR01 during biosurfactant production in a two-phase liquid-liquid batch fermentation system. The maximum rhamnolipid concentration (P ) and the yield of biosurfactant per max biomass (Y ) in a 5-L bioreactor containing soybean oil medium were found to be appr...

Transposon Tn5-GM-induced mutant strains of Pseudomonas aeruginosa which are unable to produce rhamnolipid biosurfactants and lack rhamnosyltransferase activity have been isolated. The DNA regions flanking the transposon were cloned and used as specific probes for the isolation of the corresponding wild-type genes from a P. aeruginosa wild-type cosmid gene library. Single cosmid clones capable ...

In this study, the growth of sixty-one bacterial strains in crude oil were determined spectrophotometrically at 620 nm. Pseudomonas aeruginosa G1, Pseudomonas fluorescens G6, Pseudomonas stutzeri G11 and Pseudomonas putida G15 were chosen for the study based on the efficiency of crude oil utilisation. At 1% (v/v) crude oil concentration, P. stutzeri G11 strain degraded a maximum of 69%. The per...

Rhamnolipids are biosurfactants with potential for diversified industrial and environmental uses. The present study evaluated three strategies for increasing the production of rhamnolipid-type biosurfactants produced by Pseudomonas aeruginosa strain PA1. The influence of pH, the addition of P. aeruginosa spent culture medium and the use of a fed-batch process were examined. The culture medium a...

Rigidoporus microporus is the main causal of white root disease (WRD) in rubber trees (Hevea brasiliensis). The present study investigates use rhamnolipid, a biosurfactant produced by Pseudomonas aeruginosa USM-AR2 against R. microporus. In vitro dose-responses towards rhamnolipid were determined on different isolates using poisoned food technique (PFT). Inhibition mycelial growth was found to ...