Biosurfactants produced by Bacillus circulans and Streptomyces sp. were used for biomodification of both serpentinite and quartz surfaces. The biosurfactants produced by bacteria possess the ability to decrease the surface tension of water from 72 to 28.6 mNm-1 (Bacillus circulans) and to 29.3 mNm-1 (Streptomyces sp.). This paper demonstrated biomodification of quartz and serpentinite surfaces by the biosurfactants adsorption. The effect of biosurfactants adsorption onto mineral surface properties was investigated by microflotation. Additionally, IR-ATR spectroscopy was used for characterisation of the biomodificated surfaces of quartz and serpentinite. Flotation experiments indicated that these biosurfactants effectively changed the properties of mineral surfaces and the separation of minerals can be realized.