Screening of biosurfactant producing bacteria from hydrocarbon contaminated soil

Biosurfactants are surface-active molecule produced by microorganisms and have several advantages over the chemical surfactants. The objective of this research was to obtain biosurfactant-producing bacteria from hydrocarbon contaminated soils in Jakarta Bay and to observe their biosurfactant activity through emulsification capacity and surface tension reduction capability. Overall, 19 isolates were screened for biosurfactant production by hemolysis assay, drop collapse assay and oil spreading assay. The result showed that 13 strains gave positive results on the screening tests and were determined as biosurfactant-producing bacteria. Three strains (TKY 3, TKY 14 and TKY 19) had the best biosurfactant activity. The lowest surface tension value was achieved by two strains (TKY 19 and TKY 14) with the same value of 37,84 +/- 1,45 mN/m.