To further the identification of characteristics common to Frankia strains, the phospholipids and sugars which are readily extracted with chloroform–methanol from whole cells were examined using nine strains of Frankia. Separation of extract components was achieved by thin-layer chromatography. In agreement with previous reports we have identified two phospholipids, phosphatidyl inositol and diphosphatidyl glycerol, in eight of the strains tested. All strains contained a glucose disaccharide which we have tentatively identified as trehalose on the basis of (i) comparative thin-layer and paper chromatography with standards, (ii) examination of the hydrolyzed product, and (iii) tests for reducing versus nonreducing sugars. In addition, a hexose with the chromatographic properties of glucose was observed in cultures grown on M6B complex medium. The presence of the phospholipids in Frankia strains was not affected by the age of the culture or the media on which they grew. However, the disaccharide was not present in cultures over 60 days of age, suggesting it is involved in metabolic processes. In addition, comparisons were made between extracts from Frankia and the nitrogen-fixing cyanobacterium Anabaena variabilis to determine if the glycolipids which are unique to Anabaena heterocysts are present in Frankia. These two organisms appear to have an unidentified lipid in common, but glycolipids comparable with those in Anabaena were not found in the Frankia cultures examined.
Wedge Type Paper Chromatography and Thin-Layer Chromatography of Mono-, Di-, and Trimethylamine.
