Study of the substrate influence on the free fatty acids production during growths of marine bacteria on different hydrocarbons

Among the microbial surfactants, the free fatty acids although weakly excreted possess strong tensio‐active properties affecting the solubility of hydrocarbons in the aqueous phase and can improve their availability to the microorganisms. In different hydrocarbon fermentations, an attempt to link the composition of free fatty acids excreted by a marine mixed bacterial community to the nature of the substrate has been done. No changes in their qualitative and quantitative composition have been noticed when the degradation of the substrate does not result in the formation of propionic acid. In the particular case of n‐paraffins, whose oxidation leads to the direct formation of acidic compounds, the fatty acids composition of the culture medium depends on the substrate carbon number.

Key words:

• Microbial surfactants
• fatty acids
• solubility of hydrocarbons
• marine bacterial community
• culture media
• surface tension
• GC
• GC/MS