Deoxyribonucleic acid base composition of Sporosarcina ureae

Sporosarcina halophila sp. nov., an Obligate, Slightly Halophilic Bacterium from Salt Marsh Soils

Twenty-two strains of endospore-forming sarcinae have been isolated from salt marsh soils. The isolates differ phenotypically from Sporosarcina ureae, the only species of the genus Sporosarcina which has been validly described, and are distinct from S. ureae in the composition of the cell walls of their vegetative cells. Lysine, found in the tetrapeptide of the murein of S. ureae, is replaced by ornithine in the new isolates. The interpeptide bridge consists of an aspartic acid residue instead of D-glutamylglycine as is found in S. ureae. The mol% G + C of the DNA of the new isolates is in the range of 40.1-40.9 (S. ureae 40.0-41.5). DNA hybridization studies revealed a high DNA-DNA homology within the new isolates but only a low relationship to S. ureae. The main menaquinone is of the MK-7 type as in S. ureae and other aerobic sporeformers. The spores of the new isolates are very similar to spores of S. ureae and Bacillus species in respect of their heat resistance, composition and ultrastructure. None of the new isolates grows on complex media unless supplemented with sodium, magnesium and chloride ions. Strains are slight halophiles as they grow best in the presence of 30 to 50 g NaCl/1 and 5 g MgCl(2)/l. The new isolates thus belong to a new species, for which the name Sporosarcina halophila is proposed. Strain DSM 2266 (= strain 3) is the type strain.

Peptidoglycan types of bacterial cell walls and their taxonomic implications

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Use of antibody to membrane adenosine triphosphatase in the study of bacterial relatioships

An antiserum to Ca(2+)-activated adenosine triphosphatase from membranes of Micrococcus lysodeikticus cross-reacted in agar gels with membrane adenosine triphosphatases from other pigmented micrococci and related species. Species of Micrococcus and Sarcina showed different levels of inhibition of adenosine triphosphatase activities in heterologous reactions with antiserum. Inter- and intraspecific relationships based on the inhibition reaction were compared with an independent parameter, namely the quantitative and qualitative composition of the bacterial membrane phospholipids and fatty acids. The guanine plus cytosine contents in the deoxyribonucleic acid of the species studied correlated well with the serological cross-reactivity of adenosine triphosphatases from their membranes. The types of cross-bridges found in the peptidoglycans of these cocci were also compared with the other properties. The results suggest that an antiserum specific for a major membrane protein may be a reliable and most useful adjunct in studying bacterial serotaxonomy.

Amino acid sequence of the murein of Planococcus and other Micrococcaceae

The amino acid composition and amino acid sequence of the murein (peptidoglycan) of 10 strains of planococci were studied. It is shown that the peptide subunit consists of muramyl-l-alanyl-gamma-d-glutamyl-l-lysyl-d -alanine. The cross-linking of two adjacent peptide subunits is mediated by d-glutamic acid which is bound to the epsilon-amino group of lysine by its gamma-carboxyl group and to the carboxyl group of d-alanine of an adjacent peptide subunit by its amino group. About 20 to 25% of the peptide subunits are not cross-linked. The murein structure of the different species and strains of Micrococcus, Staphylococcus, and Sarcina are compared. It is evident that the murein structure is a very good criterion for grouping the micrococci. In addition, some of these groups are fairly well defined by physiological properties as well as by their guanine + cytosine content of the deoxyribonucleic acid e.g., Micrococcus, Staphylococcus, Planococcus, Sarcina ureae. Other groups, represented by a single or a few strains only, such as M. varians NTCC 7281, M. radiodurans, M. freudenreichii ATCC 407, and M. luteus ATCC 398, need further investigation.

Biology of the sugar-fermenting Sarcinae

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