The data presented here comprise a compilation of results of physiological, serological, and other tests performed on a collection of 28 strains of "viridans" streptococci purported to be group H streptococci or Streptococcus sanguis, or both. The collection includes most of the classical strains used for many years in original and subsequent studies of group H or S sanguis physiology and serology,1-1 1 genetics,12 19 and bacterioplhages.20-22 Our study was undertaken because no publication lists these strains individually by each characteristic, the literature is often unclear on strain origins or original designations, and the definition of serologic group H is uncertain as is its synonymity with S sanguis. In addition, we tliouglht it important to characterize the strains more fully to increase their utility for genetic and phage studies.Attempts to gather the required information from the literature are relatively unrewarding. Hare' first described group H streptococci as fl-hemolytic organisms from pharyngeal isolates of normal humans, whereas S sanguis is a name given to a group of a-hemolytic or viridans streptococci originating from the blood of patients with subacute bacterial endocarditis.2 More recently, it has become obvious that S sanguis is most common on tooth surfaces and may be involved in the development of carious lesions and endocarditis, but oropharyngeal isolates represent minimal and fortuitous trappings of streptococci in passage via saliva.23-25, Efforts to relate S sanguis and group H began with the work of Dodd4 and Porter-

Mesosomal vesicles and plasma membranes were isolated from Staphylococcus aureus ATCC 6538P by protoplasting and differential centrifugation. The lipids of each of the two membrane fractions were extracted with pyridine-acetic acid-N-butanol, and the nonlipid contaminants were removed by Sephadex treatment. The lipids were then separated by passage through diethylaminoethyl-cellulose columns and characterized by thin-layer chromatographic, chemical, and spectral analyses. The lipids were separated into four discrete diethylamino

Enzyme preparations of Staphylococcus aureus were examined for their ability to solubilize 3P-labeled cell walls of the parent organism. Enzymatic activity was observed in the growth medium, in soluble fractions, and associated with native cell walls. Enzyme associated with isolated cell walls could be inactivated with formaldehyde without reducing the susceptibility of the walls to the action of added enzyme. When cells are frozen and thawed, 50 to 75% of the intracellular enzyme is released along with 2% of the intracellular protein. This freeze-thaw extracted enzyme has little, if any, activity on intact S. aureus cells. It appears that the enzyme resides near the cell wall and acts on the cell-wall inner surface.

Mesosomal vesicles and plasma membranes of Staphylococcus aureus ATCC 6538P have been prepared and examined for the presence of lipoteichoic acid. Lipids were first removed by treatment with pyridine-acetic acid-butanol (22:31:100, vol/vol/vol) and chloroform-methanol (2:1, vol/vol). Subsequently, lipoteichoic acid was removed with 40%o phenol in water. The lipoteichoic acid from mesosomal vesicles was characterized by (i) equimolar glycerol and phosphate, (ii) alanine upon hydrolysis (2 N NH,OH, 18 h, 22 C), and (iii) fatty acids, diglycerol triphosphate, glycerol monophosphate, and glycerol diphosphate upon alkaline hydrolysis (1 N NaOH, 3h, 100 C). The plasma membranes contained no lipoteichoic acid. The presence in mesosomal vesicles of 18% of the dry weight as lipoteichoic acid and its absence from plasma membranes provide the first major chemical differences between these organelles. A study of the lipoteichoic acid content in various fractions of the cell showed that the mesosomal vesicles were the major and probably the sole site for the localization of the lipoteichoic acid in these organisms. A new method for the preparation of mesosomes in increased yields is reported. A theory for the control of cell division involving lipoteichoic acid and the mesosome is proposed. This paper describes the isolation of lipoteichoic acid from mesosomal vesicles of S. aureus 209P (ATCC 6538P). Plasma membranes from this bacterium are shown to lack lipoteichoic acid. The data demonstrate a major qualitative chemical difference between mesosomal vesicles and plasma membranes and show further that most and probably all of the intracellular teichoic acid (membrane or lipoteichoic acid) is 273 on July 31, 2020 by guest http://jb.asm.org/ Downloaded from 274