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.

Alterations in the phospholipid composition of Escherichia coli B during growth at different temperatures.

The major phospholipid classes of Escherichia coli B, phosphatidyl ethanolamine, cardiolipin, and phosphatidyl glycerol, were quantitated at different stages of the growth cycle. The organisms were incubated at both 27 and 37 C. Significant differences were observed both in the amounts of total lipid phosphorus per gram (dry weight) of cells and in the relative percentages of the individual phospholipids. At 37 C the total amount of lipid phosphorus decreased significantly throughout the growth cycle. However, at 27 C total lipid phosphorus accumulated. The patterns of the three major phospholipid classes of Escherichia coli exhibited complex quantitative changes. In addition, some evidence based on glycerol to phosphate molar ratios indicated that phosphatidyl glycerolphosphate replaced phosphatidyl glycerol during the late growth stages of E. coli B when grown at 27 C. A comparative analysis of phospholipid and fatty acid patterns led to a hypothesis attempting to explain some reported variations in the lipid composition of E. coli under different conditions of growth.