Effect of cis-vaccinate acid on swarming ability of Pseudomonas aeruginosa

Abstract:

Abstract:［Objective］To study the effect of fatty acids composition on swarming mobility in Pseudomonas aeruginosa.［Methods］We constructed a fabF-knockout mutant of PAO1 (YFF-1) by double exchange principle，overexpressed FabF in YFF-1 mutant to recover the mobility，and compared the swarming ability of wild type，YFF-1 mutant and mutant with plasmid pUCP18Gm-fabF．The change of fatty acids composition was analyzed using gas chromatography to explain the difference of swarming ability.［Results］Swarming ability disappeared in YFF-1 mutant and was recovered in YFF-1 with plasmid pUCP18Gm-fabF． Gas chromatography analysis revealed that fatty acids composition changed in YFF-1．The cisvaccinate acid (C18:1Δ11) content decreased from 33.6% to 8.9%，and the ratio of unsaturated fatty acids to saturated fatty acids (UFA:SFA) was deduced from 0.96 to 0.74．The recovery of cis-vaccinate acid content was 20.9% and UFA:SFA 1.09 after expression of fabF.［Conclusion］Expression level of FabF played an important role in regulating swarming ability of PAO1．The decrease of cis-vaccinate acid content and unsaturation degree of fatty acids，especially the sharp decrease of cis-vaccinate acid，may be vital causes of swarming ability disappearance in YFF-1.

Key words:Keywords: Pseudomonas aeruginosa，fabF，swarming，cis-vaccinate acid，saturation degree of fatty acid