The Requirement for Acetate of a Streptomycin-resistant Strain of Staphylococcus aureus

Abstract

SUMMARYA streptomycin-resistant strain of Staphylococcus aureus, which requires haemin for aerobic growth, grew either aerobically or anaerobically in the absence of haemin provided the medium was supplemented with acetate or pyruvate; growth with these organic acids was increased by uracil and purines. The parent drug-sensitive strain grew aerobically without haemin but when grown anaerobically required either uracil or acetate or pyruvate. With both strains mevalonate replaced acetate and was about ten times more active.The products of glucose fermentation by both strains showed no gross difference, lactate being predominant (about 85 yo of the glucose carbon) ;only small amounts of acetate were detected. Under aerobic conditions suspensions of the parent strain oxidized glucose to acetate which accumulated. The mutant strain oxidized glucose to acetate only when previously grown with haemin or when haemin was added to the suspension of organisms. When the organism was grown with acetate in place of haemin, lactate was the predominant product. The ability of the mutant to form sufficient acetate from glucose for biosynthetic purposes is apparently dependent on a functional electron transport chain involving haemoproteins. A nicotinamide-adenine dinucleotide-linked lactate dehydrogenase and a pyruvate oxidizing system are present in extracts of both organisms. The activity of these enzymes in the mutant strain was similar whether the organisms were grown on haemin or acetate,

At the Crossroads of Bacterial Metabolism and Virulence Factor Synthesis in Staphylococci

“…During anaerobic growth, pyruvate is reduced primarily to lactic acid (115,125), with the concomitant reoxidation of NADH allowing for the continuation of glycolysis. In aerobically grown staphylococci, pyruvate is enzymatically oxidized to acetyl coenzyme A (acetyl-CoA) and CO 2 by the pyruvate dehydrogenase complex (71). AcetylCoA can be further oxidized by the TCA cycle when grown in the presence of certain citric acid cycle intermediates (77); however, the amount of acetyl-CoA that enters into the TCA cycle is low during nutrient-rich growth (40,214,219).…”

Characterization of Clinical Enterococcus faecalis Small-Colony Variants

“…In addition to determining the concentrations of the metabolites, we also measured the pHs of the culture supernatants of normal and SCV strains, since a decrease in pH (an effect of glycolysis) is an indicator of acid production during normal growth in most microorganisms (7,10). During the exponential-growth phase (2 h), the pH of the supernatant decreased slightly, to 7.3 (the pH of THY medium is 7.8), for both strains under both aerobic and microaerobic growth conditions, followed by an increase during late-exponential phase, and reached 7.9 during stationary phase (24 h) (a consequence of the generation of ammonia by amino acid catabolism [7]).…”

Anaerobiosis and the Activity of Enzymes of Pyrimidine Biosynthesis in Staphylococcus aureus

“…Further support is provided by the haem-deficient mutant SG 5 I I VAR. Pyrimidine starvation occurs in this organism when it is grown aerobically without haemin (Gardner & Lascelles, 1962). The dihydroorotate dehydrogenase activity of such cells was considerably higher than that found in organisms grown with haemin (Table 3).…”

“…This organism grows in aerated cultures at a maximum rate in the absence of haemin provided that the medium contains uracil and pyruvate; these supplements are not required when haemin is supplied. (Gardner & Lascelles, 1962). Dehydrogenase activity with oxygen as the acceptor was found in preparations from organisms grown with haemin (Table 3).…”

“…The basal medium contained Difco Casamino acids and vitamins (Gardner & Lascelles, 1962)~ supplemented with 50 m-glucose and 10 mMsodium pyruvate. Aerobic rates of growth were determined in 50 ml.…”