An isolate from garden soil, Pseudomonas aeruginosa JC2 produced rhamnolipid whose structure was determined by mass spectral analysis and was found to be L-rhamanosyl L-rhamnolsyl-b-hydroxydecanoyl-b-hydroxydecanoate. The concentration of rhamnolipid produced was checked in the presence of various nitrogen containing heterocyclic aromatic hydrocarbons (1 mM) with glucose (1%) as carbon source. Pyrazine-2-carboxylate served as best source as it contributed to the production of 240 mg/L concentration of rhamnolipid when compared with other compounds. Highest amounts of rhamnolipid (360 mg/L) were produced when 6.4 mM concentration of pyrazine-2-carboxylate was used.

Surfactants constitute an important class of industrial chemicals widely used in almost every sector of modern industry. Biosurfactants are amphiphilic compounds of microbial origin having advantages over their chemical counterparts in biodegradability and effectiveness at extreme conditions (Banat et al., 2000). Biosurfactants are produced by various microbes like Pseudomonas aeruginosa, Bacillus subtilis and also some Yeast species (Cooper and Goldenberg 1987; and Johnson et al., 1992).

Rhamnolipid, a biosurfactant containing rhamnose and b-hydroxydecanoic acid is produced by Pseudomonas aeruginosa. A mixture of rhamnolipids containing either one or two residues and two lipid chains are produced by various Pseudomonas spp. with different strains producing varying concentrations of rhamnolipids when grown on various substrates (Lang and Wulbrandt, 1999). Rhamnolipids from Pseudomonas spp. are most commonly isolated type of biosurfactants, having potential applications in agriculture, cosmetics, pharmaceuticals, personal care products, food processing, textile manufacturing, etc. The most important of it is their role in bioremediation which is attributed to their capability of increasing the bioavailability of poorly soluble organic compounds, such as polycyclic aromatics (Banat et al., 2000; and Maier and Soberón-Chávez, 2000). Though polycyclic hydrocarbons (Déziel et al., 1996) and carbohydrates (Guerra-Santos et al., 1984) were used as substrates for the production of rhamnolipids, their production in the presence of n-heterocyclic aromatic hydrocarbons is studied very little. An attempt was made to study the levels of rhamnolipids produced in the presence of heterocyclic aromatic hydrocarbons.

Life Sciences Journal, Rhamnolipid Production, Polycyclic Hydrocarbons, Polycyclic Aromatics, Heterocyclic Aromatic Hydrocarbons, Electron Spray Ionization, Commercial Production, Polycyclic Aromatic Hydrocarbons, Molecular Masses, Food Processing.