The aim of this work was to examine the structure and gene cluster of O-OPS of S. xiamenensis strain DCB-2-1 and survey its conceivability for chelating uranyl, chromate and vanadate ions from solution. O-polysaccharide (OPS, O-antigen) was isolated from the lipopolysaccharide of Shewanella xiamenensis DCB-2-1 and studied by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and sugar analysis. The following structure of the brunched pentasaccharide was established: where d-β-GlcpA(d-Ala) is d-glucuronic acid acylated with NH group of d-Ala. The OPS structure established is unique among known bacterial polysaccharide structures. Interestingly, that dN-(d-glucuronoyl)-d-alanine derivative is not found in bacterial polysaccharides early. The O-antigen gene cluster of Shewanella xiamenensis strain DCB-2-1 has been sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the OPS structure. Based on the analysis of the IR spectra of the isolated polysaccharide DCB-2-1 and the products of its interaction with UO2(NO3)2 ∗ 6H2O, NH4VO3 and K2Cr2O7, a method of binding them can be proposed. Laboratory experiments show that the use of polysaccharide can be effective in removing uranyl, chromate and vanadate from solution.

O-antigen gene cluster, bacterial O-polysaccharide structure, N-(d-glucuronoyl)-d-alanine, Shewanella xiamenensis strain DCB-2-1, uranyl, chromate and vanadate bonding

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
4,3,4,4,6	xDAla?	179.8	55.2	18.1
4,3,4,4	bDGlcpA	105.0	74.6	75.6	72.9	77.0	171.0
4,3,4	aLFucp	100.8	66.7	75.8	81.7	68.9	16.5
4,3	bDGlcp	104.4	74.9	76.3	76.3	77.7	61.2
4,2	Ac	175.7-176.3	23.5-23.7
4	bDGlcpN	103.1	56.0	84.2	69.8	76.4	62.0
2	Ac	175.7-176.3	23.5-23.7
	aDGalpN	100.5	51.3	68.9	77.8	72.0	62.7


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
4,3,4,4,6	xDAla?	-	4.23	1.43
4,3,4,4	bDGlcpA	4.62	3.46	3.57	3.62	3.88	-
4,3,4	aLFucp	4.93	3.94	3.93	4.06	4.43	1.27
4,3	bDGlcp	4.48	3.30	3.57	3.57	3.56	3.78-3.92
4,2	Ac	-	2.02
4	bDGlcpN	4.77	3.87	3.78	3.58	3.47	3.83-3.88
2	Ac	-	2.02
	aDGalpN	5.08	4.06	3.99	3.85	4.10	3.63-3.74


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
4,3,4,4,6	xDAla?		55.2/4.23	18.1/1.43
4,3,4,4	bDGlcpA	105.0/4.62	74.6/3.46	75.6/3.57	72.9/3.62	77.0/3.88	
4,3,4	aLFucp	100.8/4.93	66.7/3.94	75.8/3.93	81.7/4.06	68.9/4.43	16.5/1.27
4,3	bDGlcp	104.4/4.48	74.9/3.30	76.3/3.57	76.3/3.57	77.7/3.56	61.2/3.78-3.92
4,2	Ac		23.5-23.7/2.02
4	bDGlcpN	103.1/4.77	56.0/3.87	84.2/3.78	69.8/3.58	76.4/3.47	62.0/3.83-3.88
2	Ac		23.5-23.7/2.02
	aDGalpN	100.5/5.08	51.3/4.06	68.9/3.99	77.8/3.85	72.0/4.10	62.7/3.63-3.74

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

[*]O[C@H]1[C@H](O)[C@H](O[C@@H]2[C@@H](CO)O[C@@H](O[C@H]3[C@H](O)[C@@H](CO)O[C@@H](O[C@H]4[C@@H](CO)O[C@H]([*])[C@H](NC(C)=O)[C@H]4O)[C@@H]3NC(C)=O)[C@H](O)[C@H]2O)O[C@@H](C)[C@H]1O[C@@H]1O[C@H](C(=O)N[C@H](C)C(=O)O)[C@@H](O)[C@H](O)[C@H]1O

961.874 g/mol (C₃₇H₅₉R₂N₃O₂₆, R = next and previous repeats, not counted in mol weight)