Hansenula holstii phosphonomannan

Hansenula holstii NCYC 560 produces cell-wall, and exocellular, phosphorylated mannans of mol. wt. 10°. The cell-wall mannan contains two branched polysaccharides having (l- 2) and (1— 3) linkages, with /3-d, in addition to a-D, linkages. Phosphoric diesters are present. The exocellular phosphonomannan is composed of 3 polymers, each... 

O-Phosphonomannan/mannan Hansenula sp. Hansenula capsulata Hansenula holstii Pichia sp. Selenotila peltata... 

Mannans of Hansenula capsulata Y-1842 and H. holstii Y-2448 differ structurally from the phosphonomannan components.83 The man-nan of H. capsulata is probably a cell-wall component, and it has the linear, repeating-structure 6. Other Pichia and Hansenula mannans have predominantly linear structures.84 The 13C-n.m.r. spectrum of 6 (see Fig. 2) is distinguishable from that of the branched-chain man-nan85 from Saccharomyces rouxii (repeating unit 7.)... 

The phosphonomannan of Hansenula capsulata has a mannose to phosphate ratio of 2.5 1, which is half that of the H. holstii polymer. It consumed 1.03 moles of sodium periodate with formation of 0.31 mole of formic acid per mole of mannose residue. Autohydrolysis of the phosphonomannan gave 2-0-(6-0-phosphono-a-D-mannopyrano-syl)-D-mannose and a trisaccharide which probably has the structure depicted in (12). The cross reaction of antityphoid horse serum with the phosphonomannan of H. holstii also provides evidence for the presence of (1— 2)- or (1— 3)-linked D-mannopyranose residues, or both. ... 

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