title: Adaptation of the membrane fatty acid composition by growth in the presence of n-alkanols influences glycosyltransferase expression in Streptococcus salivarius.
abstract: Growth of Streptococcus salivarius ATCC 25975 in the presence of n-alkanols in the series methanol to decan-1-ol led to a decrease in the unsaturated to saturated fatty acid ratio. Each member of the set of n-alkanols which was examined over a range of concentrations possessed a point at which extracellular glucosyltransferase (GTF) production was minimal; increasing the concentration of the n-alkanol past this point stimulated GTF production. This effect was greatest with hexan-1-ol although it was observed to a lesser extent with pentan-1-ol and heptan-1-ol. Reduced cell-associated fructosyltransferase activity was observed with increasing concentrations of each n-alkanol. Growth in the presence of 25 mM-propan-1-ol gave rise to a fatty acid profile in which 55% of the fatty acids were of an odd chain length. S. salivarius ATCC 25975 was shown to be able to utilize ethanol in a similar manner to propan-1-ol by growing it in the presence of 400 mM-[14C]ethanol. Analysis of the membrane lipids at the stationary phase of growth indicated that 17.6% of the carbon of the fatty acids was derived from ethanol. A leaky adh mutant, S. salivarius MJ 37501, was isolated. The leaky nature of the mutant enabled it to incorporate reduced levels of odd-chain-length fatty acids into its membrane lipids when grown in the presence of 100 mM-propan-1-ol, but not when grown in the presence of 25 mM-propan-1-ol. S. salivarius ATCC 25975 therefore metabolized propan-1-ol (and ethanol) via a constitutive alcohol dehydrogenase.
mesh_terms: D000220:Adaptation, Biological; D000438:Alcohols / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005964:Glucosyltransferases / Q000378:metabolism*; D000441:Hexanols / Q000378:metabolism; D006602:Hexosyltransferases / Q000378:metabolism; D008566:Membranes / Q000378:metabolism; D013291:Streptococcus / Q000201:enzymology / Q000254:growth & development*; D001426:Bacterial Proteins
chemical_list: D000438:Alcohols; D000431:Ethanol; D005227:Fatty Acids; D005964:Glucosyltransferases; D000441:Hexanols; D006602:Hexosyltransferases; C021451:inulosucrase; D001426:Bacterial Proteins