Paenibacillus polymyxa 92, isolated from wheat roots, produced large amounts (38.4 g L-1) of exopolysaccharide (EPS) in a liquid nutrient medium containing 10 % (w/v) sucrose. The EPS was precipitated from the culture broth with cold acetone and was purified by gel filtration and anion-exchange chromatography. The molecular mass of the EPS was 2.29-1.10 × 105 Da. Diffuse reflectance infrared Fourier transform and nuclear magnetic resonance spectra showed that the EPS was a linear β-(2→6)-linked fructan (levan). Aqueous EPS solutions showed pseudoplastic behavior when shear stress was applied at different temperatures. By using the Ostwald-de Waele model, the rheological characteristics of the EPS solution were ascertained. The sorption capacity of the EPS for Zn(II), Cd(II), Pb(II), and Cu(II) was investigated. Sorption was maximal (q = 481 mg g-1) for Cu(II) ions. In model experiments, treatment of wheat seeds with EPS solution significantly increased the length of seedling roots and shoots.

exopolysaccharide, Rheology, levan, Paenibacillus polymyxa, Plant-growth-promoting activity

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
	bDFruf	61.7	105.3	78.0	76.7	81.4	64.6


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
	bDFruf	3.70-3.77	-	4.19	4.09	3.95	3.60-3.90


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
	bDFruf	61.7/3.70-3.77		78.0/4.19	76.7/4.09	81.4/3.95	64.6/3.60-3.90

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

[*]OC[C@H]1O[C@]([*])(CO)[C@@H](O)[C@@H]1O

162.141 g/mol (C₆H₁₀R₂O₅, R = next and previous repeats, not counted in mol weight)