Antibacterial Properties of Glycosylated Surfaces: Variation of the Glucosidal Moiety and Fatty Acid Conformation of Grafted Microbial Glycolipids

Abstract

<div>Glycosylated surfaces can display antimicrobial properties. It has been shown that sophorolipids can be used to develop biocidal coatings against Gram-positive and Gramnegative bacteria, but with a limited efficiency so far. Therefore, it appears necessary to further investigate the surface antibacterial activity of a broader set of structurally related glycolipids.</div><div>The present work explores the influence of the glucosidic moiety (gluco-, sophoro-, cellobio-)</div><div>and the fatty acid backbone (saturated, cis or trans monounsaturated). We show that the fatty</div><div>acid backbone plays an important role: cis derivative of sophorolipids (SL) grafted onto model</div><div>gold surfaces has better biocidal properties than saturated (SL0) and trans monounsaturated</div><div>(SLt) molecules, which appear to be inefficient. The number of glucose units is also a key factor:</div><div>a one-third decrease in antibacterial activity is observed when having one glucose unit (GL)</div><div>compared to two (SL).Sugar acetylation (SLa) does not seem to have an impact on the biocidal</div><div>properties of surfaces. These results are not limited to sophorolipids, cellobioselipids (CL)</div><div>leading to similar antibacterial observations. </div>