Study of fatty acid-bacteria interactions

Complete text of publication follows. During our work we investigated fatty acid-bacteria interactions. The antibacterial property of fatty acids was reported by several authors. Despite of them there is not reassuring explanation about the mechanism of the antibacterial activity of these compounds. An effect can considerably change in case of different structured fatty acids. Our earlier studies conduct that small changes in the structures can modify changes in their behavior towards bacteria. The stearic acid does not cause any antibacterial effects during the first few hours of the investigation, may even help the bacterial growth. However, linolic acid (C18:2) shows a strong antibacterial effect during the first hours. After 24 hours this effect wears out and the bacteria have adapted to the stress. We studied the antibacterial activity using direct bioautography. This method has the advantage to allow examining lipophilic compounds. The linoleic acid decomposes in time under different physiological conditions creating numerous oxidized molecules. This may be the reason of its antimicrobial effect. For studying this phenomenon we used infrared and mass spectroscopic methods. We applied infrared spectroscopy for indicating any changes in the spectra of the fatty acids after the interaction of fatty acids with bacteria. So we are able to deduct on what could happen during these process. We paid great attention towards the changes of double bonds, on methylation and demethylation processes. Using mass spectroscopy we searched for oxidized products that may play important role in this process. These studies are only part of our more widespreading investigations, dealing with the antimicrobial properties of fatty acids.