In standard liquid medium containing 5g mannitol l−1and 1g glutamic acid l−1, Rahizobium meliloti SU-47 cells accumulated 350 mg cyclic 1,2-β-glucans (g protein)−1. The cyclic glucans were 36% glycerol-1-phosphatesubstituted and 64% were uncharged. In the same medium with 10 g mannitol l−1, repeating units of succinoglycan (1110 mg l−1) were found as extracellular carbohydrates, and only low amouns of the succinoglycan polymer (up to 300 mg l−1) were excreted. By raising the omotic pressure of the medium by the addition of NaCl or other ionic and non-ionic osmolytes, succinoglycan production could be stimulated: up to 2·4 g l−1at 0·2 m-NaCl was produced at the expense of the repeating units. Above 0·2 m-NaCl growth was slowed down, and succinoglycan excretion diminished. At 1 m-NaCl growth stopped completely. In standard medium containing 0·6 m-NaCl the amount of cellular cyclic 1,2-β-glucans was lowered to 150 mg (g protein)−1out of which the glycerol-1-phosphatesubstituted glucan fraction was reduced to 15%. Instead, high amounts of oliogosaccharides were synthesized as osmoprotectants, with trehalose as the major component [up to 200 mg (g protein)−1]. Glycogen synthesis was completely suppressed at this salt conenctration, while poly β-hydroxyutyric acid syntheis was unaffected.
AbeM.,
AmemuraA.,
HigashiA.1982; Studies on cyclic β-(1,2)- glucan obtained from the periplasmic space of Rhizobium trifolii cells. Plant and Soil 64:315–324
AmemuraA.,
HisamatsuM.,
MitaniH.1983; Cyclic (1,2)-β-d-glucan and the octasaccharide repeating units of extracellular acidic polysaccharides produced by Rhizobium
. Carbohydrate Research 114:277–285
AmemuraA.,
FootrakulP.,
KoizumiK.,
UtamuraT.,
TaguchiH.1985; Isolation of (1,2)-β-d-glucans from tropical strains of Rhizobiumand determination of their degrees of polymerization. Journal of Fermentation Technology 63:115–120
BatleyM.,
RedmondJ. W.,
DjordjevicS. P.,
RolffB. G.1987; Characterization of glycerophosphorylated cyclic β-(1,2)- glucans from a fast growing Rhizobium species. Biochimica et Siophysica Acta 901:119–126
BerryA.,
DevaultJ. D.,
ChakrabartyA. M.1989; High osmolarity is a signal for enhanced algD transcription in mucoid and nonmucoid Pseudomonas aeruginosa strains. Journal of Bacteriology 171:2312–2317
BlakeneyA. B.,
HarrisP. J.,
HenryR. J.,
StoneB. A.1983; A simple and rapid preparation of alditol-acetates for monosaccharide analysis. Carbohydrate Research 113:291–299
BrauneggG.,
SonnleiterB.,
LapfertyR. M.1978; A rapid gaschromatographic method for the determination of ply-β-hydroxybutyric acid in microbial biomass. European Journal of Applied Microbiology 6:29–31
BreedveldM. W.,
ZevenhuizenL. P. T. M.,
ZehnderA. J. B.1990; Excessive excretion of cyclic β-(1,2)-glucan by Rhizobium trifolii TA-1. Applied and Environmental Microbiology 56:2080–2086
HaradaT.,
AmemuraA.1981; Bacterial β-glycans: succinoglycan and curdlan. Memorials of the Institute of Scientific and Industrial Research, Osaka University 38:37–49
HarrisP. J.,
HenryR. J.,
BlakeneyA. B.,
StoneB. A.1984; An improved procedure for the methylation analysis of oligosaccharides and polysaccharides. Carbohydrate Research 127:59–73
HismtsuM.,
SanoK.,
AmemuraA.,
HaradaT.1978; Acidic polysaccharides containing succinic acid in various strains of Agrobacteriwn
. Carbohydrate Research 61:89–96
LeighJ. A.,
SignerE. R.,
WalkerG. C.1985; Exopolysaccharide-deficient mutants of Rhizobium meliloti that form ineffective nodules. Proceedings of the National Academy of Sciences of the United States of America 82:6231–6235
LintonJ. D.,
EvansM.,
JonesD. S.,
GouldneyD. N.1987; Exocellularsuccinoglucan production by Agrobacterium radiobacterNCIB 11883. Journal of General Microbiology 133:2961–2969
LongS.,
ReedJ. W.,
HimawanJ.,
WalkerG. C.1988; Genetic analysis of a cluster of genes required for synthesis of the calcofluor- binding exopolysaccharide of Rhizobium meliloti
. Journal of Bacteriology 170:4239–4248
MillerK. J.,
KennedyE. P.,
ReinholdV. N.1986; Osmotic adaptation by Gram-negative bacteria: possible role for periplasmic oligosaccharides. Science 231:48–51
MillerK. J.,
ReinholdV. N.,
WeissbornA. C.,
KennedyE. P.1987; Cyclic glucans produced by Agrobacterium tumefaciens are substituted with sn-1-phosphoglycerol residues. Biochimica et Biophysica Acta 901:112–118
MorrisV. J.,
BrownseyG. J.,
HarrisJ. E.,
GunningA. P.,
StevensB. J. H.,
JohnstonA. W. B.1989; Cation-dependent gelation of the acidic extracellular polysaccharides of Rhizobium leguminosarum: a non-specific mechanism for the attachment of bacteria to plant roots. Carbohydrate Research 191:315–320
SchulmanH.,
KennedyE. P.1979; Localization of membrane-derived oligosaccharides in the outer envelope of Escherichia coli and their occurrence in other Gram-negative bacteria. Journal of Bacteriology 137:686–688
TrevelyanW. E.,
HarrisonJ. S.1952; Studies on yeast metabolism. I. Fractionation and microdetermination of cell carbohydrates. Biochemical Journal 50:298–310
UsuiT.,
YokoyamaM.,
YamaokaN.,
MatsudaK.,
TuzimuraK.1974; Proton magnetic resonance spectra of d-gluco-oligosaccharides and d-glucans. Carbohydrate Research 33:105–116
VincentJ. M.1974; Root-nodule symbiosis with Rhizobium
. In The Biology of Nitrogen Fixation pp. 265–342QuispelA.
Edited by Amsterdam: North Holland Publishing Co;
ZevenhuizenL. P. T. M.1981; Cellular glycogen, β-(1,2)-glucan, poly-β-hydroxybutyric acid and extracellular polysaccharides in fast growing species of Rhizobium
. Antonie van Leeuwenhoek 47:481–497
ZevenhuizenL. P. T. M.1984; Gel-forming capsular polysaccharide of fast-growing rhizobia: occurrence and rheological properties. Applied Microbiology and Biotechnology 20:393–399
ZevenhuizenL. P. T. M.,
Van NeervenA. R. W.1983; (1,2)-β-d-Glucan and acidic oligosaccharides produced by Rhizobium meliloti
. Carbohydrate Research 118:127–134
ZevenhuizenL.P.T.M.,
Van VeldhuizenA.,
FokkensR. H.1990; Re-examination of cellular β-(1,2)-glucans of Rhizobiaceae: distribution of ring sizes and degrees of glycerol-1-phosphate substitution. Antonie van Leeuwenhoek 57:173–178
ZhanH.,
LeveryS. B.,
LeeC. C.,
LeighJ. A.1989; A second exopolysaccharide of Rhizobium meliloti strain SU-47 that can function in root nodule invasion. Proceedings of the National Academy of Sciences of the United States of America 86:3055–3059