Accumulation of Neutral Amino Acids by Streptococcus faecalis

Accumulation of amino acids by calf lens.

Calf lens has the capacity for accumulating proline, hydroxyproline, tyrosine, and tryptophan from a buffered salt medium supplemented with glucose. Sufficient energy to accomplish this task can be derived from anaerobic glycolysis. Apparently a variety of neutral amino acids can enter the lens by a common path, if fudged by the existence of competitive effects. Ouabain, an inhibitor of active ...

The assimilation of amino-acids by bacteria; action of inhibitors on the accumulation of free glutamic acid in Staphylococcus aureus and Streptococcus faecalis.

Certain Gram-positive bacteria have the ability to concentrate certain amino-acids in the free state within the cell (Gale, 1947; Taylor, 1947). Aminoacids may pass across the cell wall either by a process of diffusion, as in the case of lysine which becomes concentrated within the cell by a form of Donnan effect (Najjar & Gale, 1950), or as a result of an active transfer which requires energy ...

The assimilation of amino-acids by bacteria. 9. The passage of lysine across the cell wall of Streptococcus faecalis.

Effects of fatty acids on lysis of Streptococcus faecalis.

Palmitic, stearic, oleic, and linoleic acids at concentrations of 200 nmol/ml all inhibited autolysin activity 80% or more in whole cells or cell-free extracts. This concentration of the saturated fatty acids palmitic acid and stearic acid had little or no effect on the growth of whole cells or protoplasts. However, the unsaturated fatty acids oleic acid and linoleic acid induced lysis in both ...

Uptake of Branched-Chain Amino Acids by Streptococcus thermophilus.

The transport of branched-chain amino acids in Streptococcus thermophilus was energy dependent. The metabolic inhibitors of glycolysis and ATPase enzymes were active, but the proton-conducting uncouplers were not. Transport was optimal at temperatures of between 30 and 45 degrees C and at pH 7.0 for the three amino acids leucine, valine, and isoleucine; a second peak existed at pH 5.0 with vali...