Chemical and biological studies on the lipopolysaccharide (O-antigen) of Anacystis nidulans

Katz, A.; Weckesser, Jürgen; Drews, Gerhart; Mayer, Hubert

doi:10.1007/bf00492032

Cited by 40 publications

(29 citation statements)

References 40 publications

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“…Following this "normalization", an LD 50 = 2.5 mg/kg was indicated for LPS isolated from Anacystis nidulans strain KM in the paper by Katz et al (1977). However, LPS doses in this case are not fully comparable to those in the other studies, since adrenalectomised mice were used, and it is known that adrenalectomy sensitises mice to the lethal effects of LPS.…”

Section: Acute Toxicitymentioning

confidence: 99%

Review and analysis of occurrence, exposure and toxicity of cyanobacteria toxins in food

Testai

Buratti

Funari

et al. 2016

EFS3

105

125

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This report presents the extensive literature search conducted on 1) the occurrence of different cyanotoxins in food matrices; 2) the analytical methods for their detection; 3) their toxicological profile; 3) the environmental factors affecting toxicity of cyanobacterial population and 4) the combined effects of mixtures of cyanotoxins and other chemicals. It also includes a review of guidelines values or health-alert levels for cyanotoxins in food (or drinking water) adopted world-wide. The methodological aspects and the queries used in the extensive literature search, the collection and screening of retrieved papers and the inventory are briefly described in the report; all details are available in 3 supplementary appendices to this report. The analysis of collected papers indicated that most of them are focused on a single microcystin (MC) variant (MC-LR) out of the almost 100 MC known. Many studies on occurrence are affected by limited quality, due to analytical drawbacks in the detection methods and were not considered in the exposure assessment. Toxicity studies useful for the derivation of health based reference values are few, being many of them carried out using i.p. injection, which is poorly representative of actual human exposure. In addition, those toxicological studies carried out with poorly characterised cyanobacterial extracts or focused on single parameters, using a single dose, devoted to elucidation of mechanism of action, reporting qualitative description of effects were not used for data extraction. The relevant exposure scenarios are also described, although being the available data on exposure very limited, no definite conclusion on the health risks for the exposed population could be drawn. However, the possibility of risky exposure is evidenced for fish and shell-fish consumers and for blue-green algae supplements (BGAS) as well in relation to MC contamination. Finally, many data gaps were identified. © European Food Safety Authority, 2016Key words: Cyanobacteria, cyanotoxins, occurrence, toxicity, exposure, risk assessment, data gaps. Question number: EFSA-Q-2015-00141Correspondence:sc.secretariat@efsa.europa.eu Cyanotoxins in foodThe present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the Authority is subject. It may not be considered as an output adopted by the Authority. The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.www.efsa.europa.eu/publications 2 EFSA Supporting publication 2016:EN-998NDisclaimer: The present document has been produced and adopted by the bodies identified above as author(s). This task has b...

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Section: Acute Toxicitymentioning

confidence: 99%

Review and analysis of occurrence, exposure and toxicity of cyanobacteria toxins in food

Testai

Buratti

Funari

et al. 2016

EFS3

105

125

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“…On the other hand, the cyanobacterial O antigen is reminiscent of the Escherichia coli O antigen (69,130) and is responsible for cyanophage adsorption (108) or endotoxic activity in aquatic environments (71; S. Fukuoka, Q. Adil, H. Kakita, and H. Obika, J. Endotoxin Res. 3: 35,1996).…”

mentioning

confidence: 99%

Cyanobacterial Cell Walls: News from an Unusual Prokaryotic Envelope

2000

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“…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.…”

mentioning

confidence: 99%

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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Chemical and biological studies on the lipopolysaccharide (O-antigen) of Anacystis nidulans

Cited by 40 publications

References 40 publications

Review and analysis of occurrence, exposure and toxicity of cyanobacteria toxins in food

Review and analysis of occurrence, exposure and toxicity of cyanobacteria toxins in food

Cyanobacterial Cell Walls: News from an Unusual Prokaryotic Envelope

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

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