Abstract: Materials of particular utility in separating hydrocarbon values from mineral deposits, e.g. bitumen from tar sands, are prepared by a microbiological fermentation process using certain selected microorganisms. The fermentation process is conducted under aerobic conditions, with the selected microorganisms growing on a hydrocarbon substrate. The materials have surfactant properties, in greater or lesser degree. The materials may be subsequently separated from the fermentation broth, or alternatively the broth may be used as is, since it contains relatively large proportions of suitable separation effecting materials.