RHAMNOLIPIDS—BRIEF OUTLINE Biosurfactants, widely known as surfaceactive agents of biological origin, have carved a niche for themselves in the market due to their unique environmentfriendly properties. They have come a long way since first biosurfactant “surfactin” was purified and characterized by Arima et al. (1968). Biosurfactants have been researched thoroughly and satisfactorily since the...

The Pseudomonas aeruginosa rhlAB operon encodes the enzyme rhamnosyltransferase 1, which produces the biosurfactant mono-rhamnolipid; rhlAB induction is dependent on the quorum-sensing transcription activator RhlR complexed with the autoinducer N-butyryl-homoserine lactone (C(4)-HSL). In this work we studied rhlAB induction in a P. aeruginosa and Escherichia coli background. We found that, in b...

P. aeruginosa M14808 was screened to produce rhamnolipid with high yield by mutation in a high magneto-gravitational environment. After silica gel columniation chromatogram, the components of the crude biosurfactant extract were analyzed by TLC, FTIR, and ESI-MS. The major components were characterized as rhamnolipids. The rhamnolipids consisted of two main types, monoand di-rhamnolipids. Di-rh...

A Pseudomonas aeruginosa mutant derived by random mutagenesis with N-methyl-N-nitro-Nnitrosoguanidine, producing high levels of the rhamnolipid biosurfactants was selected on SiegmundWagner (SW) plates. The mutant designated P. aeruginosa PTCC1637 produces rhamnolipids at concentrations 10 time more than parent strain. NMR analysis and surface tension measurement showed that the biosurfactants...