A novel class of sulfur-containing aminolipids widespread in marine roseobacters

Abstract

Marine roseobacter group bacteria are numerically abundant and ecologically important players in ocean ecosystems. These bacteria are capable of modifying their membrane lipid composition in response to environmental change. Remarkably, a variety of lipids are produced in these bacteria, including phosphorus-containing glycerophospholipids and several amino acid-containing aminolipids such as ornithine lipids and glutamine lipids. Here, we present the identification and characterization of a novel sulfur-containing aminolipid (SAL) in roseobacters. Using high resolution accurate mass spectrometry, a SAL was found in the lipid extract of Ruegeria pomeroyi DSS-3 and Phaeobacter inhibens DSM 17395. Using comparative genomics, transposon mutagenesis and targeted gene knockout, we identified a gene encoding a putative lyso-lipid acyltransferase, designated SalA, which is essential for the biosynthesis of this SAL. Multiple sequence analysis and structural modelling suggest that SalA is a novel member of the lysophosphatidic acid acyltransferase (LPAAT) family, the prototype of which is the PlsC acyltransferase responsible for the biosynthesis of the phospholipid phosphatidic acid. SAL appears to play a key role in biofilm formation in roseobacters. SalA is widely distributed in Tara Oceans metagenomes and actively expressed in Tara Oceans metatranscriptomes. Our results raise the importance of sulfur-containing membrane aminolipids in marine bacteria.

Exploitation of Marine Molecules to Manage Alzheimer’s Disease

“…This molecule has been documented in red algae ( Botryocladia leptopoda , Acanthophora spicifera, Gelidium micropterum, Hypnea boergesenii d, Gracilaria corticate, Gracilaria arcuate, Gracilaria pygmaea, Grateloupia livida, Chondrus ocellatus, Rhodymenia palmata, Acrosorium uncinatum, Actinotrichia fragilis, Helminthocladia australis ), green algae ( Caulerpa racemosa, Cladophora densa, Ulva fasciata ), brown algae ( Cystoseira indica, Cystoseira trinodis, Sargassum tenerrimum, Dictyota dichotoma, Cystoseira myrica, Iyengaria stellate, Padina boergesenii ), and unicellular green algae (prasinophytes such as Ostreococcus and Micromonas ) [ 173 , 174 , 175 ]. Recently, it was found for the first time in bacteria [ 176 ]. Among these species, the higher amounts of homotaurine are found in the red algae species H. boergesenii , G. corticate , and G. pygmaea with amounts of 702, 475, and 333 µg/g, respectively.…”

Aminolipids elicit functional trade-offs between competitiveness and bacteriophage attachment in Ruegeria pomeroyi

“…OL biosynthesis in some bacteria such as Vibrio and Serratia can also be mediated by a fusion protein named OlsF which contains an Nterminus OlsB-like domain and a C-terminus OlsA-like domain [5,6]. Several other aminolipids have been documented recently, including glycine-and lysine-containing aminolipids in Bacteroidetes and Pseudopedobacter and a sulfonate-containing aminolipid in roseobacters, respectively [7][8][9].…”