Abstract

The aim of the present study is to evaluate biosurfactant production by two strains of Pseudomonas spp. using alternative carbon sources. The bacterial strains used were isolated from the Municipal Park of Mucugê, Bahia State, Brazil. Different vegetable oils and glycerol concentrations were evaluated and used individually, as the sole source of carbon and energy for the production of biosurfactant which was measured by the test of emulsification and surface tension. The best concentration of alternative substrates achieved was 0.5%, with emulsion formation rates ranging from 50 to 59% for both bacterial strains analyzed. The free-cell broth ofPseudomonas strains had the ability to reduce the surface tension of all culture media tested, although it was more effective when glycerol was used. The results confirm the potential of these alternative substrates, based on the availability and low cost of these raw materials, to reduce the final production cost and also the expenses with waste treatment.

Key words: Pseudomonas, biosurfactants, substrates, renewable-resources.

Abbreviation

TSA, Triptic soyer agar; MSM, mineral saline medium; TSB, tryptic soy broth; ST, surface tension; CMC, critical micellar concentration; SDS, sodium dodecyl sulfate; PAHs, polycyclic aromatic hydrocarbons; LCFAs, long chain fatty acids.