Heterocyst glycolipids from nitrogen-fixing cyanobacteria other than nostocaceae

Gambacorta, Agata; Pagnotta, Eduardo; Romano, Ida; Sodano, G.; Trincone, Antonio

doi:10.1016/s0031-9422(97)00954-0

Cited by 45 publications

(55 citation statements)

References 5 publications

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“…strain PCC 7120 could be involved both in the first step of synthesis of O antigen and in transfer of a side-branch galactosyl residue of the heterocyst envelope polysaccharide. Although galactosyl residues have been reported to be present in some heterocyst envelope glycolipids (19,31), they were not found in those glycolipids from PCC 7120. Mutants DR1822 and DR1963 both form the same glycolipid components as does the wild-type strain, and the transfer of glycolipids from the protoplast is also not curtailed.…”

Section: Discussionmentioning

confidence: 81%

Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120

Khudyakov

Wölk

1997

J Bacteriol

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FoxLipopolysaccharide (LPS) is a major component of the outer membrane of gram-negative bacteria. The diverse O antigen portion is an important determinant of the surface character of the cells, including their outer membrane permeability (38), electrical charge (44), reactivity to antibodies, and susceptibility to phages (32), and so affects the adaptation of bacteria to their environments. LPSs of many bacteria also show potent endotoxin activity (22). In cyanobacteria, LPS may adsorb cyanophage (42), and its endotoxin activity may affect aquatic habitats (25).LPS consists of three covalently linked domains: lipid A, oligosaccharide core, and O antigen. The O antigen portion is comprised of serially repeated, strain-specific oligosaccharide units. This polymer of oligosaccharide units is the immunodominant portion of the LPS and often serves as a bacteriophage receptor. Assembly of the lipid A-core portion and synthesis of the O antigen units are directed by the rfa and rfb genes, respectively. In a "block" mechanism of O antigen synthesis, repeating subunits of the O antigen, synthesized by sequential transfer of monosaccharide constituents to a lipid carrier at the cytosolic side of the cytoplasmic membrane, are transported to the periplasmic side of the cell membrane and polymerized. The polymerization, directed by rfc genes, entails transfer of an already synthesized unit or polymer of units to the reducing terminus of a single lipid-linked unit (34,45). Assembly of LPS is completed by ligation of an entire polysaccharide chain to oligosaccharide core-lipid A. Finally, LPS is translocated to the outer membrane. All of the enzymes, lipid carriers, intermediates, and LPS itself are membrane bound. In this mechanism for LPS synthesis, the first monosaccharide residue transferred to a lipid carrier is galactose-1-phosphate. The gene, rfbP, responsible for the transfer of that galactosyl residue is indicative of the block mechanism of LPS synthesis. An alternative, monomeric mechanism of O antigen synthesis proceeds at the cytoplasmic membrane by sequential addition of mannosyl residues to the nonreducing terminus of the forming chain and leads to the synthesis of an LPS in which the repeating subunit of O antigen contains three or five interlinked mannosyl residues (22,45).Cyanobacteria are a group of oxygenic, photosynthetic gram-negative bacteria. Although the wall of cyanobacterial vegetative cells has been incompletely defined, chemically, LPS is typically a constituent and contains domains that are similar to those in other bacteria (14). The LPS of the unicellular species Anacystis nidulans KM has been studied in detail (24). Its O antigen, reminiscent of the O antigen of Escherichia coli O8 and O9, contains 1,4-interlinked trisaccharides of 1,3-linked mannosyl residues. As in other phototrophic bacteria, some of the mannosyl residues are methylated. The O antigen of a filamentous species, Anabaena variabilis, contains L-acofriose, L-rhamnose, D-mannose, D-glucose, and D-galactose (50), suggestive of a b...

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Section: Discussionmentioning

confidence: 81%

Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120

Khudyakov

Wölk

1997

J Bacteriol

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“…These components consist of long-chain diols, triols, keto-ols, and keto-diols that are glycosidically bound to hexose molecules (see Fig. S1) (13,14). To the best of our knowledge, HGs have not been reported in any other organism and thus they represent excellent tracers not only for heterocystous cyanobacteria but also for the N 2 fixation process itself.…”

Section: Resultsmentioning

confidence: 99%

Fossilized glycolipids reveal past oceanic N ₂ fixation by heterocystous cyanobacteria

Bauersachs

Speelman

Hopmans

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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N 2 -fixing cyanobacteria play an essential role in sustaining primary productivity in contemporary oceans and freshwater systems. However, the significance of N 2 -fixing cyanobacteria in past nitrogen cycling is difficult to establish as their preservation potential is relatively poor and specific biological markers are presently lacking. Heterocystous N 2 -fixing cyanobacteria synthesize unique long-chain glycolipids in the cell envelope covering the heterocyst cell to protect the oxygen-sensitive nitrogenase enzyme. We found that these heterocyst glycolipids are remarkably well preserved in (ancient) lacustrine and marine sediments, unambiguously indicating the (past) presence of N 2 -fixing heterocystous cyanobacteria. Analysis of Pleistocene sediments of the eastern Mediterranean Sea showed that heterocystous cyanobacteria, likely as epiphytes in symbiosis with planktonic diatoms, were particularly abundant during deposition of sapropels. Eocene Arctic Ocean sediments deposited at a time of large Azolla blooms contained glycolipids typical for heterocystous cyanobacteria presently living in symbiosis with the freshwater fern Azolla, indicating that this symbiosis already existed in that time. Our study thus suggests that heterocystous cyanobacteria played a major role in adding "new" fixed nitrogen to surface waters in past stratified oceans.nitrogen fixation | intact polar lipids | cyanobacterial biomarkers | symbiosis | saproprel

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“…The composition of HGs in cyanobacteria is known to be related to their taxonomy (Bauersachs et al, 2009a(Bauersachs et al, , 2014aGambacorta et al, 1995Gambacorta et al, , 1998Schouten et al, 2013;Wörmer et al, 2012). Hence, we compared the distribution of the HGs observed in our sedimentary record of the Baltic Sea with the HGs produced in vitro by different heterocystous cyanobacterial species.…”

Section: The Distribution Of Hgsmentioning

confidence: 99%

“…Gas exchange is believed to be regulated by the heterocyst cell wall, which consists of two separate polysaccharide and glycolipid layers (Murry and Wolk, 1989;Walsby, 1985), of which the latter acts as the gas diffusion barrier. These layers, known as heterocyst glycolipids (HGs), have been found to date to be unique to heterocyst-forming cyanobacteria (Bryce et al, 1972;Nichols and Wood, 1968), and furthermore their composition has been discovered to be distinct at the level of families and even genera (Bauersachs et al, 2009a(Bauersachs et al, , 2014aGambacorta et al, 1998;Schouten et al, 2013). Their structure comprises a sugar moiety glycosidically bound to a long n-alkyl chain ( Fig.…”

Section: Introductionmentioning

confidence: 99%

“…Their structure comprises a sugar moiety glycosidically bound to a long n-alkyl chain ( Fig. 1) with an even number of carbon atoms (26 to 32) with various functional groups (hydroxyl and keto groups) located at the C-3, ω-1 and ω-3 positions (Gambacorta et al, 1995(Gambacorta et al, , 1998Schouten et al, 2013). The sugar moiety of HGs found in nonsymbiotic cyanobacteria is typically a hexose (hereafter C 6 ) (Bryce et al, 1972;Lambein and Wolk, 1973;Nichols and Wood, 1968), while HGs associated with endosymbiotic heterocystous cyanobacteria have a pentose moiety (hereafter C 5 ) (Bale et al, 2015(Bale et al, , 2017Schouten et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

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The Holocene sedimentary record of cyanobacterial glycolipids in the Baltic Sea: an evaluation of their application as tracers of past nitrogen fixation

et al. 2017

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Abstract. Heterocyst glycolipids (HGs) are lipids exclusively produced by heterocystous dinitrogen-fixing cyanobacteria. The Baltic Sea is an ideal environment to study the distribution of HGs and test their potential as biomarkers because of its recurring summer phytoplankton blooms, dominated by a few heterocystous cyanobacterial species of the genera Nodularia and Aphanizomenon. A multi-core and a gravity core from the Gotland Basin were analyzed to determine the abundance and distribution of a suite of selected HGs at a high resolution to investigate the changes in past cyanobacterial communities during the Holocene. The HG distribution of the sediments deposited during the Modern Warm Period (MoWP) was compared with those of cultivated heterocystous cyanobacteria, including those isolated from Baltic Sea waters, revealing high similarity. However, the abundance of HGs dropped substantially with depth, and this may be caused by either a decrease in the occurrence of the cyanobacterial blooms or diagenesis, resulting in partial destruction of the HGs. The record also shows that the HG distribution has remained stable since the Baltic turned into a brackish semi-enclosed basin ∼ 7200 cal. yr BP. This suggests that the heterocystous cyanobacterial species composition remained relatively stable as well. During the earlier freshwater phase of the Baltic (i.e., the Ancylus Lake and Yoldia Sea phases), the distribution of the HGs varied much more than in the subsequent brackish phase, and the absolute abundance of HGs was much lower than during the brackish phase. This suggests that the cyanobacterial community adjusted to the different environmental conditions in the basin. Our results confirm the potential of HGs as a specific biomarker of heterocystous cyanobacteria in paleo-environmental studies.

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Heterocyst glycolipids from nitrogen-fixing cyanobacteria other than nostocaceae

Cited by 45 publications

References 5 publications

Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120

Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120

Fossilized glycolipids reveal past oceanic N ₂ fixation by heterocystous cyanobacteria

The Holocene sedimentary record of cyanobacterial glycolipids in the Baltic Sea: an evaluation of their application as tracers of past nitrogen fixation

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Heterocyst glycolipids from nitrogen-fixing cyanobacteria other than nostocaceae

Cited by 45 publications

References 5 publications

Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120

Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120

Fossilized glycolipids reveal past oceanic N 2 fixation by heterocystous cyanobacteria

The Holocene sedimentary record of cyanobacterial glycolipids in the Baltic Sea: an evaluation of their application as tracers of past nitrogen fixation

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Fossilized glycolipids reveal past oceanic N ₂ fixation by heterocystous cyanobacteria