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Cell wall hydrolysates of nine strains of extremely halophilic cocci all contained gylcine, glucosamine, galactosamine, and gulosaminuronic acid. Muramic acid was not present in any of the strains.

Although there is agreement on the fact that Sarcina lutea strain FD-533 has branched C-29 monoalkenes as major hydrocarbon components, there is disagreement in the literature as to the nature of the branching. This has been resolved by analyses of the fatty acids produced by permanganate-periodate treatment of each of the resolvable hydrocarbon fractions making up the C-29 complex. The three major components are identified as doubly branched, Delta(13) species with two iso terminations, one iso and one anteiso termination, and two anteiso terminations.

The composition and nature of the fatty acids and hydrocarbons of Sarcina lutea were elucidated by gas chromatography and by combined gas chromatography-mass spectrometry. The distribution of fatty acids found in S. lutea showed two families of pairs, or dyads, of saturated monocarboxylic acids (C12-C18) with and without methyl branching. These pairs of fatty acids showed a pattern of iso and anteiso structures for C13, C15, and C17, and iso and normal structures for C12, C14, and C16. Only the C18 showed unsaturation. The distribution of hydrocarbons in the range C22-C29 showed two families of tetrads of unsaturated aliphatic hydrocarbons all showing methyl branching. Each tetrad was composed of four isomers identified as two iso olefins and two anteiso olefins. The only difference between the tetrads pertaining to different families was found in the relative gas chromatographic retention times of the last two components of each group.

Sarcina lutea was grown in Trypticase Soy Broth, Nutrient Broth, and a chemically defined medium. Gas chromatographic analysis of lipid components demonstrated that the composition of the medium had an effect on the relative per cent composition of the aliphatic hydrocarbons and fatty acids present in the cells. The branched olefinic hydrocarbons from the organisms grown in Trypticase Soy Broth showed no predominance or only a slight predominance of odd-numbered carbon chains, whereas the hydrocarbons from cells grown in the other two media showed an obvious predominance of odd-numbered carbon chains. The monocarboxylic fatty acid content and distribution showed only minor differences, with all normal saturated fatty acids present in relatively small quantities for cells grown in Nutrient Broth and in a chemically defined medium.

Eight natural DNAs of widely differing base composition have been studied by x-ray diffraction in fibers at high relative humidity. The resulting type B diffraction diagrams showed that all of the DNAs had a 34-A pitch and 3.4-A interbase pair separation. However, the intensity distribution on the inner three layer lines was a strong function of the base content. In diffraction diagrams of very AT-rich DNA, the intensity of the first and third layer line was 2- or 3-times stronger than in the patterns of GC-rich DNA. These high humidity diffraction patterns agree with x-ray scattering from solutions of DNA. The results are interpreted to imply that each AT base pair may have a different cross section than a GC pair. If this is so, it would appreciably alter the currently held ideas concerning DNA recognition.

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.