The emulsifying activity of several hydrocarbon-degrading microorganisms

Abstract

It is known that biosurfactants are capable of increasing the bioavailability of hydro
carbons in oil and petroleum products, as well as modifying the external surfaces of bacteria by
hydrophobizing providing direct contact with hydrocarbon molecules. In this study the index of
emulsification index was studied for four hydrocarbon-degrading strains of microorganisms such as
Achromobacter xylosoxidans, Bacillus subtillus, Tessaracoccus flavescens, Acinetobacter calcoaceti
cus. Diesel fuel and hexadecane were used as hydrophobic substrates.
It is shown that for all members of natural hydrocarbon-degrading microorganisms are charac
terized by high rates of emulsification index. The highest index of emulsificationis has shown for
Acinetobacter calcoaceticus- 80-87%. Microorganisms having an emulsification index bigger than
50% are considered promising producers of surfactants. Since the microbial cell oxidizes hydrocar
bons by adsorbing on their surface, as a result, the oil-oxidizing activity of the crops depends on its
ability to utilize the hydrocarbon substrate. This could indicate adestructive activity of microor
ganisms.