title: Characterization of Pseudomonas aeruginosa fatty acid profiles in biofilms and batch planktonic cultures.
abstract: The fatty acid composition of Pseudomonas aeruginosa PAO1 was compared between biofilm and batch planktonic cultures. Strain PAO1 biofilms were able to maintain a consistent fatty acid profile for up to 6 days, whereas strain PAO1 batch planktonic cultures showed a gradual loss of cis-monounsaturated fatty acids over 4 days. Biofilms exhibited a greater proportion of hydroxy fatty acids but a lower proportion of both cyclopropane fatty acids and saturated fatty acids (SAFAs). SAFAs with >=16 carbons, in particular, decreased in biofilms when compared with that in batch planktonic cultures. A reduced proportion of SAFAs and a decline in overall fatty acid chain length indicate more fluidic biophysical properties for cell membranes of P. aeruginosa in biofilms. Separating the biofilms into 2 partitions and comparing their fatty acid compositions revealed additional trends that were not observed in the whole biofilm: the shear-nonremovable layer consistently showed greater proportions of hydroxy fatty acid than the bulk liquid + shear-removable portion of the biofilm. The shear-nonremovable portion demonstrated a relatively immediate decline in the proportion of monounsaturated fatty acids between days 2 and 4; which was offset by an increase in the proportion of cyclopropane fatty acids, specifically 19:0cyc(11,12). Simultaneously, the shear-removable portion of the biofilm showed an increase in the proportion of trans-monounsaturated fatty acids and cyclopropane fatty acids.
authors.affiliation: Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3, Canada.
authors.forename: Jerry
authors.initials: J
authors.lastname: Chao
authors.forename: Gideon M
authors.initials: GM
authors.lastname: Wolfaardt
authors.forename: Michael T
authors.initials: MT
authors.lastname: Arts
mesh_terms: D018441:Biofilms; D003521:Cyclopropanes / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis*; D010933:Plankton; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000254:growth & development*; D013997:Time Factors
chemical_list: D003521:Cyclopropanes; D005227:Fatty Acids; C028775:cyclopropane fatty acids