Structural Characteristics and Biological Properties of Pseudomonas fluorescens Lipopolysaccharides

Sn, Veremecheĭnko; Ma, Vodianik; Gm, Zdorovenko

doi:10.1007/s10438-005-0062-0

Cited by 5 publications

(7 citation statements)

References 15 publications

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“…However, as in the LPS of other Pseudomonas representatives, the carbohydrate content was not high and ranged from 9.06 to 21.5 % (Table 1). The results obtained agree with the data of other authors [21,22] on the content of carbohydrates in LPS preparations of representatives of the species P. fruorescens, which is phylogenetically closely related to P. mandelii.…”

Section: Methodssupporting

confidence: 91%

Lipopolysaccharide of Pseudomonas mandelii, Isolated from Antarctica

Броварська¹,

Varbanets²,

Gladka³

et al. 2021

Mikrobiol. Z.

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Representatives of the Pseudomonas mandelii species are able to exist and multiply in places where the temperature is constantly low. The optimum growth temperature for P. mandelii is 25–30°C, although this bacterium can grow at 4°C but not at 37°C. Therefore, P. mandelii is an excellent example of psychrotolerant bacterium which like psychrophilic bacteria is characterized by a number of structural and functional adaptations that facilitate survival at low temperatures. To understand these microorganisms’ role in Antarctica the characterization of its biopolymers is vital. One of these biopolymers is lipopolysaccharide (LPS), composition and structure of which are diagnostically significant. This determines the aim of the work – to isolate lipopolysaccharides from the cells of Antarctic strain of P. mandelii, grown at different temperatures, to characterize them chemically, and to study their functional and biological activity. Methods. The object of the study was Pseudomonas sp. U1, isolated from moss on Galindez Island in Antarctica. Lipopolysaccharides were extracted from dried cells by 45% phenol water solution at 65–68°С by Westphal and Jann method. The amount of carbohydrates was determined by phenol-sulfuric method. Carbohydrate content was determined in accordance to the calibration curve, which was built using glucose as a standard. The content of nucleic acids was determined by Spirin, protein − by Lowry method. Serological activity of LPS was investigated by double immunodiffusion in agar using the method of Ouchterlony. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAAG electrophoresis) was performed according to Laemmli. Results. As a result of phylogenetic analysis (programs ClustalX 2.1, Tree view, Mega v. 6.00) it was shown that the Antarctic bacterial strain Pseudomonas sp. U1 associated with green moss has a 99.4% homology with the type strain from the GenBank database NR024902 P. mandelii CIP 105273T. According to these data and proximity to the corresponding cluster of species, the studied isolate can be identified as P. mandelii. A characteristic feature of LPS isolated from P. mandelii cells, grown at different temperatures (20°C and 4°C) is their heterogeneity. This is evidenced by the data of the monosaccharide composition, electrophoretic distribution, which showed that P. mandelii produces S- and SR-forms of LPS, differed in the length of the O-specific polysaccharide chains. The R-form of LPS is also present, which does not contain an O-specific polysaccharide chains. Structural heterogeneity is also inherent in LPS lipid A. This is evidenced by the data of the fatty acid composition. In LPS grown at 4°C no unsaturated fatty acids were found, while such ones are synthesized in LPS of other bacteria grown in the cold, in response to a decrease in growth temperature. The study of the immunochemical properties of LPS was carried out using polyclonal O-antisera as antibodies, and LPS as antigens indicated that in homologous systems LPS exhibited serological activity. LPS obtained from P. mandelii U1 cells, grown at 20°C, had a complex antigenic composition and gave two clear lines of precipitation at a concentration of 1 mg/mL. LPS obtained from P. mandelii U1 cells, grown at 4°C, gave one line, which indicates their serological homogeneity. Conclusions. For the first time lipopolysaccharides were isolated from cells of P. mandelii U1, grown at 4°C and 20°С. A characteristic feature of these LPS is their heterogeneity. This is evidenced by the data of the monosaccharide and fatty acid composition, electrophoretic distribution, which showed that P. mandelii produces S- and SR-forms of LPS, differed in the length of the O-specific polysaccharide chains. LPS, obtained from cells, grown at different temperatures, are differed by serological activity.

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Section: Methodssupporting

confidence: 91%

Lipopolysaccharide of Pseudomonas mandelii, Isolated from Antarctica

Броварська¹,

Varbanets²,

Gladka³

et al. 2021

Mikrobiol. Z.

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“…The lack of detectable amounts (<01.%) of Kdo and other hexose residues indicated that these samples lacked core LPS but still retained significant amounts of A‐band LPS. Significantly, these samples did not contain detectable levels of any other carbohydrate residue that may have been present in the core LPS molecule (the core LPS composition of P. fluorescens SBW25 has not been reported, but is known to be highly varied amongst other strains of this bacterium; Naberezhnykh et al ., 1987; Knirel et al ., 1996; Shashkov et al ., 1998; Veremeichenko, 1998; Veremeichenko and Zdorovenko, 1994; 1996; Zdorovenko et al ., 1999) which might have confounded our interpretation of the composition of the matrix material itself.…”

Section: Resultsmentioning

confidence: 99%

Biofilm formation at the air–liquid interface by the Pseudomonas fluorescens SBW25 wrinkly spreader requires an acetylated form of cellulose

Spiers

Bohannon

Gehrig

et al. 2003

Molecular Microbiology

395

462

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SummaryThe wrinkly spreader (WS) genotype of Pseudomonas fluorescens SBW25 colonizes the air-liquid interface of spatially structured microcosms resulting in formation of a thick biofilm. Its ability to colonize this niche is largely due to overproduction of a cellulosic polymer, the product of the wss operon. Chemical analysis of the biofilm matrix shows that the cellulosic polymer is partially acetylated cellulose, which is consistent with predictions of gene function based on in silico analysis of wss . Both polar and non-polar mutations in the sixth gene of the wss operon ( wssF ) or adjacent downstream genes ( wssGHIJ ) generated mutants that overproduce non-acetylated cellulose, thus implicating WssFGHIJ in acetylation of cellulose. WssGHI are homologues of AlgFIJ from P. aeruginosa , which together are necessary and sufficient to acetylate alginate polymer. WssF belongs to a newly established Pfam family and is predicted to provide acyl groups to WssGHI. The role of WssJ is unclear, but its similarity to MinD-like proteins suggests a role in polar localization of the acetylation complex. Fluorescent microscopy of Calcofluor-stained biofilms revealed a matrix structure composed of networks of cellulose fibres, sheets and clumped material. Quantitative analyses of biofilm structure showed that acetylation of cellulose is important for effective colonization of the air-liquid interface: mutants identical to WS, but defective in enzymes required for acetylation produced biofilms with altered physical properties. In addition, mutants producing non-acetylated cellulose were unable to spread rapidly across solid surfaces. Inclusion in these assays of a WS mutant with a defect in the GGDEF regulator (WspR) confirmed the requirement for this protein in expression of both acetylated cellulose polymer and bacterial attachment. These results suggest a model in which WspR regulation of cellulose expression and attachment plays a role in the co-ordination of surface colonization.

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“…Lipopolysaccharide acetylation activity has been proposed for the latter enzyme (King et al, 2009), but remains to be verified. The repeating units constituting the O-specific polysaccharide chains of LPS in P. fluorescens LMG 1794 have been determined and consist of L-rhamnose and N-acetyl-D-fucose (Veremecheĭnko et al, 2005). Given that PA5238 was suggested to play a role in O-acetylation of the LPS core and not of the repeating units (King et al, 2009), we thus do not expect these two carbohydrate residues to interact with LlpB PfluA506 .…”

Section: Genes Affected In Llpb-resistant Mutants Indicate a Key Rolementioning

confidence: 99%

LlpB represents a second subclass of lectin‐like bacteriocins

Ghequire

Mot

2019

Microbial Biotechnology

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Summary Bacteriocins are secreted bacterial proteins that selectively kill related strains. Lectin‐like bacteriocins are atypical bacteriocins not requiring a cognate immunity factor and have been primarily studied in Pseudomonas . These so‐called LlpAs are composed of a tandem of B‐lectin domains. One domain interacts with d ‐rhamnose residues in the common polysaccharide antigen of Pseudomonas lipopolysaccharide ( LPS ). The other lectin domain is crucial for interference with the outer membrane protein assembly machinery by interacting with surface‐exposed loops of its central component BamA. Via genome mining, we identified a second subclass of Pseudomonas lectin‐like proteins, termed LlpB, consisting of a single B‐lectin domain. We show that these proteins also display bactericidal activity. Among LlpB‐resistant transposon mutants of an LlpB‐susceptible Pseudomona s strain, a major subset was hit in an acyltransferase gene, predicted to be involved in LPS core modification, hereby suggesting that LlpBs equally attach to LPS for surface anchoring. This indicates that LPS binding and target strain specificity are condensed in a single B‐lectin domain. The identification of this second subclass of lectin‐like bacteriocins further expands the toolbox of antibacterial warfare deployed by bacteria and holds potential for their integration in biotechnological applications.

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Structural Characteristics and Biological Properties of Pseudomonas fluorescens Lipopolysaccharides

Cited by 5 publications

References 15 publications

Lipopolysaccharide of Pseudomonas mandelii, Isolated from Antarctica

Lipopolysaccharide of Pseudomonas mandelii, Isolated from Antarctica

Biofilm formation at the air–liquid interface by the Pseudomonas fluorescens SBW25 wrinkly spreader requires an acetylated form of cellulose

LlpB represents a second subclass of lectin‐like bacteriocins

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