• Korean Journal of Microbiology
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• v.33 no.3
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• pp.187-192
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• 1997

The strain producing biosurfactant was isolated from soil. The isolated strain was identified as the genus Tsukamurella through its morphological, cultural, physiological, menaquinone type, fatty acid composition characteristics. The highest biosurfactant production by Tsukamurella sp. 26A was observed after 4 days cultivation in the culture medium containing n-hexadecane 7%, $NaNO_{3}$ 0.2%, $K_2HPO_4$ 0.001%, $MgSO_{4}$ center dot $7H_{2}O$ 0.02%, $CaCl_2$ center dot $2H_{2}O$ 0.02%, yeast extract 0.02%(pH 6.8-7.0, 30^{\circ}C.$ The surface and interfacial tension of an aqueous solution reached 30 mNim and 1.5 mNim, respectively. The biosurfactant stabilized oil-in-water emulsion with a variety of hydrocarbons, edible oils and petroleum oils.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.170-175
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• 2004

In this paper we studied about Bacillus sp. TBM40-3 producing biosurfactants. The strains were isolated from Taeback Mountain soil and identified as Bacillus sp. by l6S rDNA nucleotides sequence analysis. The TBM40-3 was gram-positive and rod-shaped as observed by field emission scanning microscopy. After the cultivation TBM40-3 in LB broth for 90 h and the surface tension of supernatant was decreased to 29 mN/m. Emulsification activity and stability of crude biosurfactant was measured by using water-immiscible hydrocarbons and oil as substrate. Maximum emulsification activity and stability was obtained from soybean oil. Also, we confirmed that the TBM40-3 producing biosurfactant had an effect on crude oil while showing a superior effect as compared to chemically synthesized surfactants (SDS, Span85, Tween40, Triton X-100). As a result, the Bacillus sp. TBM40-3 producing biosurfactant had potent properties as an emulsifying agent and an emulsion stabilizing agent.