Evidence of multiple branching in the levan elaborated by Streptococcus salivarius strain 51

Marshall, Keith; Weigel, Helmut

doi:10.1016/s0008-6215(00)84544-9

Cited by 15 publications

(9 citation statements)

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“…inulin types [(,B-(2,1)-linked] (2,17,18,39,53,55,66). The ability of oral bacteria to produce these short-half-life polymers allows for a more effective utilization of dietary sucrose, since cleavage of this disaccharide with the concomitant incorporation of the glucose and fructose moieties into nondiffusing polymers attenuates the loss of carbohydrate from the plaque matrix.…”

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Characterization of the Streptococcus mutans GS-5 fruA gene encoding exo-beta-D-fructosidase

Burne

Penders

1992

Infect Immun

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The complete nucleotide sequence (5,010 bp) of the fructanase gene (fruA) and flanking regions of the chromosome of Streptococcus mutans GS-5 was determined. The fruA gene appears to be the sole transcript arising from a proximal promoter. The presumed precursor of the secreted FruA protein consists of 1,423 amino acids, and it has an Mr of 158,656 and a pI of 4.82. The N terminus of FruA has characteristics in common with signal peptides of gram-positive organisms. The C terminus consists of a serineand threonine-rich region, followed by the peptide LPDTGD, 4 charged amino acids, 21 amino acids with a strongly hydrophobic character, and a charged pentapeptide tail, which are proposed to correspond to the wallspanning region, the LPXTGX consensus sequence, and the membrane-spanning domains of surface-associated proteins of gram-positive cocci. The FruA protein has significant homology with the BaciUus subtilis levanase (SacC), the Bacteroidesfragilis levanase (ScrL), yeast invertases, and a number of other 1-fructosidases but not with fructosyltransferase, glucosyltransferases, or glucan-binding proteins of oral streptococci. Genes with homology to fiuA were detected in S. mutans serotype c, e, and f strains, Streptococcus ratus, Streptococcus salivarius, and Streptococcus sanguis. A deletion derivative of FruA lacking the C-terminal 437 amino acids was still functional and could hydrolyze 13-(2,6)and P-(2,1)-linked sugars, but with altered preference for substrates. The data begin to define functional domains of the FruA protein and potential regulatory sites for induction, repression, growth rate control, and posttranslational localization of this multifunctional enzyme.

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“…Fructans appear to be produced in dental plaque primarily 4622 BURNE AND PENDERS by oral streptococci and actinomycetes, which synthesize both levans and inulins (2,17,18,39,53,55,60,66). Likewise, these bacteria are probably responsible for the vast majority of the enzymatic hydrolysis of fructans by dental plaque samples (10,11,15,38,61).…”

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Characterization of the Streptococcus mutans GS-5 fruA gene encoding exo-beta-D-fructosidase

Burne

Penders

1992

Infect Immun

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“…The structures of the fructans produced by many of these organisms have been analyzed, and it appears as though S. salivarius (3,12,13,32) and the actinomycetes (3, 49) produce a levan-type fructan, consisting predominantly of ,B(2->6)-linked fructosyl units with a significant degree of branching in the 1 position (13, 32). S. mutans, on the other hand, produces an inulin-type fructan which is made up almost exclusively of 1(2-l) linkages with some branching in the 6 position (2, 3, 12, 38).…”

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Expression, purification, and characterization of an exo-beta-D-fructosidase of Streptococcus mutans

et al. 1987

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A genetic library of Streptococcus mutans GS-5, constructed in an Escherichia coli plasmid vector, was screened for cells which could utilize sucrose as the sole carbon and energy source. The recombinant plasmid pFRU1, containing a 4.2-kilobase pair insert of S. mutans DNA, was shown to confer this phenotype. Further characterization of the gene product encoded by pFRUl revealed that the enzyme was a P-D-fructosidase with the highest specificity for the j(2-*6)-linked fructan polymer levan. The enzyme could also hydrolyze inulin [13(2-+1)-linked fructan], sucrose, and raffinose with 34, 21, and 12%, respectively, of the activity observed for levan. The gene (designated fruA) appeared to be expressed under its own control in E. coli, as judged by the lack of influence on gene product activity of induction or repression of the ,I-galactosidase promoter adjacent to the insertion site on the cloning vector. The protein was purified to homogeneity, as judged by silver staining of purified protein in denaturing and reducing conditions in polyacrylamide gels, from sonic lysate of E. coli, as well as from culture supernatants of S. mutans GS-5 grown in a chemostat at low dilution rate with fructose as the sole carbohydrate source. Both purified proteins had an apparent molecular mass of 140,000 daltons in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were immunologically related and comigrated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as determined by Western blotting with antisera raised against the cloned gene product, and were identical in all physical and biochemical properties tested. The pH optimum of the enzyme acting on fructan polymers was 5.5, with a significant amount of activity remaining at pH 4.0. The optimum pH for sucrose degradation was broader and lower, with a peak at approximately 4.5.Enzyme activity was inhibited almost completely by Hg2' and Ag2+, inhibited partially by Cu2+, not inhibited by fluoride ion or Tris, and slightly stimulated by Mn2' and Co2+. Fructan polymers were attacked exohydrolytically by the enzyme, fructose being the only product released. With sufficient time, both levan and inulin were degraded to completion, with no evidence of product inhibition.Several bacteria which normally inhabit the human mouth, including Streptococcus mutans (2,3,12,18,38), S. salivarius (3, 12, 13, 33), S. sanguis (24), and Actinomyces viscosus (3, 49), can synthesize polymers of D-fructose. The structures of the fructans produced by many of these organisms have been analyzed, and it appears as though S. salivarius (3,12,13,32) and the actinomycetes (3, 49) produce a levan-type fructan, consisting predominantly of ,B(2->6)-linked fructosyl units with a significant degree of branching in the 1 position (13, 32). S. mutans, on the other hand, produces an inulin-type fructan which is made up almost exclusively of 1(2-l) linkages with some branching in the 6 position (2, 3, 12, 38). In some cases, the physical properties of the fructan polymers have been examined, and gene...

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“…Carbon and nitrogen sources is the important factor in production of extracellular polysaccharide by microorganisms [14,28]. The assimilation of various carbon and nitrogen sources by as Pseudomonas sp.…”

Section: Effect Of Carbon and Nitrogen Sources On The Extracellular Pmentioning

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Production and Characterization of Extracellular Polysaccharide Produced by Pseudomonas sp. GP32

Lee¹,

Lee²,

Suh

2015

Journal of Life Science

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A strain GP32 which produces a highly viscous extracellular polysaccharide was conducted with soil samples and identified as Pseudomonas species. The culture flask conditions for the production of extracellular polysaccharide by Pseudomonas sp. GP32 were investigated. The most suitable carbon and nitrogen source for extracellular polysaccharide production were galactose and (NH4)2SO4. The optimum carbon/nitrogen ratio for the production of extracellular polysaccharide was around 50. The optimum pH and temperature for extracellular polysaccharide production was 7.5 and 32℃, respectively. In batch fermentation using a jar fermentor, the highest extracellular polysaccharide content (15.7 g/l) was obtained after 70 hr of cultivation. The extracellular polysaccharide produced by Pseudomonas sp. GP32 (designated Biopol32) was purified by ethanol precipitation, cetylpyridinium chloride (CPC) precipitation, and gel permeation chromatography. Biopol32, which has an estimated molecular weight of over 3×10 7 datons, is a novel polysaccharide derived from sugar components consisting of galactose, glucose, gulcouronic acid and galactouronic acid in an approximate molar ratio of 1.85 : 3.24 : 1.00 : 1.42. The solution of Biopol32 showed non-Newtonian characteristics. The viscosity of Biopol32 exhibited appeared to be higher at all concentration compared to that of zooglan from Zoogloea ramigera. An analysis of the flocculating efficiency of Biopol32 in industry wastewater (food, textile, and paper wastewater) revealed chemical oxygen demand (COD) reduction rates 58.4-67.3% and suspended solid (SS) removal rates 82.6-91.3%. Based on these results, Biopol32 is a possible candidate for industrial applications such as wastewater treatment.

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Evidence of multiple branching in the levan elaborated by Streptococcus salivarius strain 51

Cited by 15 publications

References 14 publications

Characterization of the Streptococcus mutans GS-5 fruA gene encoding exo-beta-D-fructosidase

Characterization of the Streptococcus mutans GS-5 fruA gene encoding exo-beta-D-fructosidase

Expression, purification, and characterization of an exo-beta-D-fructosidase of Streptococcus mutans

Production and Characterization of Extracellular Polysaccharide Produced by Pseudomonas sp. GP32

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