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A technique for isolation of ATP from microorganisms is suggested. The technique is based on increasing permeability of the cell membrane for substances of low molecular weight during dehydration. Treatment of the dry biomass with boiling water gives a higher yield of ATP from the cells of eukaryote and prokaryote microorganisms as compared with other techniques, and permits to register the amount of APT at the moment of experiment.

Poly-beta-hydroxybutyrate granules exhibited a strong orange fluorescence when stained with Nile blue A. Heat-fixed cells were treated with 1% Nile blue A for 10 min and were observed at an excitation wavelength of 460 nm. Glycogen and polyphosphate did not stain. Nile blue A appears to be a more specific stain for poly-beta-hydroxybutyrate than Sudan black B.

Exopolysaccharides from ten strains of oligonitrophilic bacteria were found to contain galactose, glucose and mannose. Strains belonging to the genus Mycobacterium contained also fucose, ramnose and three sugars that had not been identified: two of them were lipophilic and one had a lower Rf than ramnose. A correlation has been established between the composition of monosaccharides, their molar ratios in exocellular polysaccharides of oligonitrophilic bacteria, and the taxonomy of these microorganisms. Sporeforming bacteria belonging to the genus Bacillus produce polysaccharides which contain galactose, glucose and mannose at a ratio of 10:19: : (13--15). The molar ratio between the same sugars in exopolysaccharides of bacteria belonging to the genera Pseudomonas and Azotomonas is 10:(12--19) : (4--6). The ratio between galactose, glucose, mannose, fucose, ramnose, the unknown sugar and the sum of two lipophilic sugars in exocellular polysaccharides of the genus Mycobacterium is 10:(15--16) : (5--6) : (7--10) : (0.1--9) : (0.3--0.5) : (0.4--0.8).

Poly-beta-hydroxybutyrate (PHB) from various representative strains of the genera Azotobacter, Beijerinckia, and Derxia was isolated and characterized. During growth in shake culture, with glucose as a carbon and energy source, and molecular nitrogen as a nitrogen source, increase in dry weight appeared linear, and PHB formed a constant percentage of the dry weight. In a medium containing 1% (w/v) glucose, PHB declined with the onset of the stationary phase of growth; with 2% (w/v) glucose, an increase in PHB content during stationary phase was noted in the case of some strains, before a subsequent decline. The decrease in PHB as a percentage of dry cellular weight (not of total amount present in the culture) during growth of some strains with 2% as opposed to 1% (w/v) glucose may be ascribed to a greater production of capsular polysaccharide. PHB content could not be used as a taxonomic criterion. Strain differences were as great as or greater than species differences. The only strain of Beijerinckia fluminensis obtained contained PHB, but it could not be grown on the nitrogen-free medium used. Two species of the genus Azotomonas, reported to be aerobic, nonsymbiotic nitrogen-fixers, did not grow on the nitrogen-free medium used and did not produce PHB during growth with a combined nitrogen source.

The ribosomal proteins from nine species of prokaryotes have been compared by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The stained gels were scanned spectrophotometrically, the weight and number average molecular weights were calculated, and the detailed distribution of the proteins as a function of molecular weight was determined. By all of these criteria, the ribosomal proteins from all the species closely resembled each other, despite differences in the pattern of protein bands by conventional disc-gel electrophoresis. Therefore, it is suggested that the structural requirements for the assembly of ribosomal subunits have imposed limitations on the evolution of the ribosomal proteins and that their size has been highly conserved.