2-O-Methyl-D-mannose, a key sugar in the taxonomy of Frankia

Publisher Website
Google Scholar
Abstract
The classification of actinomycetes in the genus Frankia Brunchorst has been based partly on morphology but primarily on their ability to form N2-fixing nodules on roots of actinorhizal host plants. To identify nonsporulating and noninfective Frankia isolates, biochemical tests are needed. Sugars present in whole-cell hydrolysates have proven useful in the taxonomy of other genera of actinomycetes. We, and others, have found a sugar in all Frankia isolates examined thus far that is absent in all other actinomycetes tested. After reduction with NaBD2H4 and acetylation, the characteristic sugar was found by gas chromatographic and mass spectrometric analyses to be a 2-O-methyl hexose. The sugar was partially purified by high pressure liquid chromatography and demethylated to give a major product of mannose. Authentic 2-O-methyl mannose as its alditol acetate and trimethylsilyl methyl glycoside derivatives cochromatographed with the sugar. By gas–liquid chromatography of its trimethylsilyl (−)-2-butyl glycoside, the marker sugar was found to be 2-O-methyl-D-mannose. The 2-O-methyl-D-mannose was present in all 68 strains of Frankia isolated from the actinorhizae of seven species of Alnus, two species of Elaeagnus, and one species each of Myrica, Comptonia, and Shepherdia. These actinorhizal host plants originated from different provenances in Canada, U.S.A., France, and Holland.

This publication has 0 references indexed in Scilit: