title: Impact of temperature on ladderane lipid distribution in anammox bacteria.
abstract: Anaerobic ammonium-oxidizing (anammox) bacteria have the unique ability to synthesize fatty acids containing linearly concatenated cyclobutane rings, termed "ladderane lipids." In this study we investigated the effect of temperature on the ladderane lipid composition and distribution in anammox enrichment cultures, marine particulate organic matter, and surface sediments. Under controlled laboratory conditions we observed an increase in the amount of C(20) [5]-ladderane fatty acids compared with the amount of C(18) [5]-ladderane fatty acids with increasing temperature and also an increase in the amount of C(18) [5]-ladderane fatty acids compared with the amount of C(20) [5]-ladderane fatty acids with decreasing temperature. Combining these data with results from the natural environment showed a significant (R(2) = 0.85, P = <0.0001, n = 121) positive sigmoidal relationship between the amounts of C(18) and C(20) [5]-ladderane fatty acids and the in situ temperature; i.e., there is an increase in the relative abundance of C(18) [5]-ladderane fatty acids at lower temperatures and vice versa, particularly at temperatures between 12 degrees C and 20 degrees C. Novel shorter (C(16)) and longer (C(22) to C(24)) ladderane fatty acids were also identified, but their relative amounts were small and did not change with temperature. The adaptation of ladderane fatty acid chain length to temperature changes is similar to the regulation of common fatty acid composition in other bacteria and may be the result of maintaining constant membrane fluidity under different temperature regimens (homeoviscous adaptation). Our results can potentially be used to discriminate between the origins of ladderane lipids in marine sediments, i.e., to determine if ladderanes are produced in situ in relatively cold surface sediments or if they are fossil remnants originating from the warmer upper water column.
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 1790 AB Den Burg, Texel, the Netherlands.
authors.forename: Jayne E
authors.initials: JE
authors.lastname: Rattray
authors.forename: Jack
authors.initials: J
authors.lastname: van de Vossenberg
authors.forename: Andrea
authors.initials: A
authors.lastname: Jaeschke
authors.forename: Ellen C
authors.initials: EC
authors.lastname: Hopmans
authors.forename: Stuart G
authors.initials: SG
authors.lastname: Wakeham
authors.forename: Gaute
authors.initials: G
authors.lastname: Lavik
authors.forename: Marcel M M
authors.initials: MM
authors.lastname: Kuypers
authors.forename: Marc
authors.initials: M
authors.lastname: Strous
authors.forename: Mike S M
authors.initials: MS
authors.lastname: Jetten
authors.forename: Stefan
authors.initials: S
authors.lastname: Schouten
authors.forename: Jaap S
authors.initials: JS
authors.lastname: Sinninghe Damsté
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001421:Bacteria, Anaerobic / Q000378:metabolism* / Q000528:radiation effects*; D050356:Lipid Metabolism; D010084:Oxidation-Reduction; D013696:Temperature
chemical_list: D000641:Ammonia