The organelle nature of a particle isolated from Bacillus stearothermophilus

Cytological and chemical studies of the growth of protoplasts of Bacillus megaterium

Aeration of protoplasts of Bacillus megaterium in a succinate buffered nutrient broth led to marked growth similar to that already described by McQuillen, and the degree of chromatin synthesis in these growing forms prompted a combined cytological and chemical study. Growth was followed by phase contrast and by Feulgen stains, as well as by lipide phosphorus, nucleic acid, and protein analyses. In slide cultures, growth and compression led to monstrous flattened forms with readily visible, but coalescent nuclear structures. In fluid cultures, the protoplasts grew as phase dense spheres. Orderly reproduction of apparently discrete nuclear bodies was observed during the initial hours of spherical growth, but in older cultures, the chromatin arrangement tended to be more haphazard and was influenced by the concentration of Mg ions. In the same medium, protoplasts free of lysis showed a linear rise in optical density, while vegetative cells exhibited an exponential increase. However, protoplasts were able to synthesize DNA at the same rate as vegetative cells, but their increase of RNA was always less. Thus, as they grew, the ratio RNA/DNA fell. The lipide P increased in proportion to the expanding surface. With growth and lysis, large amounts of water-insoluble slime accumulated. Analyses indicate it to be a phospholipoprotein material containing some RNA.

Electron transport particles from Bacillus stearothermophilus

Downey, Ronald J. (University of Nebraska, Lincoln), Carl E. Georgi, and Walter E. Militzer. Electron transport particles from Bacillus stearothermophilus. J. Bacteriol. 83:1140-1146. 1962-Electron-transport particles (ETP) have been isolated from Bacillus stearothermophilus. They are capable of oxidizing such substrates as succinate, malate, diphosphopyridine nucleotide, p-phenylenediamine, and hydroquinone. Difference spectra indicated bands of cytochromes a(3), b, and c. A chromatographic procedure for purification of cytochrome c has been described. The role of quinonelike intermediates in the ETP was implied by the restorative effect of coenzyme Q and vitamin K(1) on material treated with lipid solvent. Isolation and identification of coenzyme Q from the thermophile indicated it was similar to coenzyme Q(10) of mammalian sources.

Phospholipids from Bacillus stearothermophilus

The lipids of Bacillus stearothermophilus strain 2184 were extracted with chloroform-methanol and separated into neutral lipid and three phospholipid fractions by chromatography on silicic acid columns. The phospholipids were identified by specific staining reactions on silicic acid-impregnated paper, by chromatography of alkaline and acid hydrolysis products, and by determination of acyl ester:glycerol:nitrogen:phosphorus molar ratios. The total extractable lipid was 8% of the dry weight of whole cells and consisted of 30 to 40% neutral lipid and 60 to 70% phospholipid. The phospholipid consisted of diphosphatidyl glycerol (23 to 42%), phosphatidyl glycerol (22 to 39%), and phosphatidyl ethanolamine (21 to 32%). The concentrations of diphosphatidyl glycerol and phosphatidyl glycerol were lower in 2-hr cells than in 4- and 8-hr cells. Whole cells were fractionated by sonic treatment and differential centrifugation. The total lipid content, expressed in per cent of dry weight of each fraction was: whole protoplasts, 10%; membrane fraction, 18%; 30,000 x g particulate fraction, 22%; and 105,000 x g particulate fraction, 26%. The relative phospholipid concentrations in each fraction were about the same. As had been previously reported, none of the phospholipid was stable to alkaline hydrolysis.

ISOLATION AND CHARACTERIZATION OF NUCLEAR BODIES FROM PROTOPLASTS OF BACILLUS MEGATERIUM1

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Electron-scattering granules and reducing sites in mycobacteria

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