The Thin-Layer Chromatography Analysis of Phospholipids in *Vibrio fischeri* with a Focus on Cardiolipin

Abstract

Cardiolipin is found in bacterial and mitochondrial membranes, making it a compound that is found in virtually all organisms. While the physical properties of cardiolipin are known, most of the functions and significance of this phospholipid are simply hypothesized. In the case of Helicobacter pylori and Vibrio fischeri, cardiolipin is hypothesized to be essential for the production of flagellar sheaths and bacterial mobility. However, the absence of cardiolipin-producing genes in V. fischeri did not affect its motor function. As a result, I will be studying the presence of cardiolipin in multiple V. fischeri mutants with genes coding for cardiolipin removed in order to detect other possible genes responsible for cardiolipin production or to conclude that perhaps cardiolipin is nonessential for flagella synthesis. The method of analysis used for this research includes lipid extraction and thin-layer chromatography in order to compare the presence and relative concentrations of phospholipids present in V. fischeri. The results of the thin-layer chromatography interestingly revealed a high concentration of phosphatidylglycerol (PG); when comparing the structures of PG with cardiolipin, it is revealed that the hydrophilic heads of both phospholipids are similar. This suggests that V. fischeri is able to retain its flagellar sheaths and motor function due to PG undertaking the same functions of cardiolipin. This study increases the current body of knowledge of cardiolipin, allowing for a basis of further research.