Pseudomonas veronii 2E, an autochthonous bacterium isolated from sediments associated to a high-polluted watershed, produces a complex matrix of exopolymers with carbohydrates as main components. In this work, four polysaccharides were isolated from the extracellular material. The major acidic polysaccharide named EPO2, was purified and its structure was elucidated using Matrix-assisted laser desorption/ionization and Electrospray ionization mass spectrometry, Infrared spectroscopy, Nuclear magnetic resonance spectroscopy and chemical treatments. This heteropolysaccharide consists in an α(1→4) glucan substituted with N-Acetylglucosamine residues and with a branching α-D-GlcpA-(1→3)-L-Fucp disaccharide. The biosorption capacity of EPO2 and of the whole exopolysaccharide to Pb(II), Zn(II), Cu(II) and Fe(II) was evaluated. EPO2 showed a remarkable sorption capacity for Fe(II) with an efficiency of 70% and for Zn(II) 39%. When the whole exopolysaccharide fraction was tested it showed a significantly lower metal sorption ability than purified EPO2 suggesting the involvement of the distinct acidic branching disaccharide in this interaction.

LOS, exopolysaccharide, Bioremediation, Extracellular polymeric substances, Pseudomonas veronii 2E

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
3	aDGlcpA	100.5	72.1	72.4	71.4	71.3	173.08
	bLFucp	96.1	72.4	81.6	70.8	71.1	15.4


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
3	aDGlcpA	5.2	3.56	3.79	3.55	4.28	-
	bLFucp	4.53	3.57	3.66	3.52	3.74	1.17


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
3	aDGlcpA	100.5/5.2	72.1/3.56	72.4/3.79	71.4/3.55	71.3/4.28	
	bLFucp	96.1/4.53	72.4/3.57	81.6/3.66	70.8/3.52	71.1/3.74	15.4/1.17

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

C[C@@H]1O[C@H](O)[C@@H](O)[C@H](O[C@H]2O[C@H](C(=O)O)[C@@H](O)[C@H](O)[C@H]2O)[C@@H]1O

340.281 g/mol (C₁₂H₂₀O₁₁)

Pseudomonas veronii 2E, an autochthonous bacterium isolated from sediments associated to a high-polluted watershed, produces a complex matrix of exopolymers with carbohydrates as main components. In this work, four polysaccharides were isolated from the extracellular material. The major acidic polysaccharide named EPO2, was purified and its structure was elucidated using Matrix-assisted laser desorption/ionization and Electrospray ionization mass spectrometry, Infrared spectroscopy, Nuclear magnetic resonance spectroscopy and chemical treatments. This heteropolysaccharide consists in an α(1→4) glucan substituted with N-Acetylglucosamine residues and with a branching α-D-GlcpA-(1→3)-L-Fucp disaccharide. The biosorption capacity of EPO2 and of the whole exopolysaccharide to Pb(II), Zn(II), Cu(II) and Fe(II) was evaluated. EPO2 showed a remarkable sorption capacity for Fe(II) with an efficiency of 70% and for Zn(II) 39%. When the whole exopolysaccharide fraction was tested it showed a significantly lower metal sorption ability than purified EPO2 suggesting the involvement of the distinct acidic branching disaccharide in this interaction.

LOS, exopolysaccharide, Bioremediation, Extracellular polymeric substances, Pseudomonas veronii 2E

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
3	aDGlcpA	100.5	72.1	72.4	71.4	71.3	173.08
	aLFucp	92.1	?	78	71.5	66.2	15.3


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
3	aDGlcpA	5.2	3.56	3.79	3.55	4.28	-
	aLFucp	5.14	3.88	3.89	3.54	4.13	1.12


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
3	aDGlcpA	100.5/5.2	72.1/3.56	72.4/3.79	71.4/3.55	71.3/4.28	
	aLFucp	92.1/5.14	?/3.88	78/3.89	71.5/3.54	66.2/4.13	15.3/1.12

The spectrum also has 1 signal at unknown position (not plotted).

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

C[C@@H]1O[C@@H](O)[C@@H](O)[C@H](O[C@H]2O[C@H](C(=O)O)[C@@H](O)[C@H](O)[C@H]2O)[C@@H]1O

340.281 g/mol (C₁₂H₂₀O₁₁)