Second system for potassium transport in Streptococcus faecalis

Energy coupling to potassium transport in Streptococcus faecalis. Interplay of ATP and the protonmotive force.

We have studied the mechanism by which metabolic energy is coupled to potassium accumulation by the fermentative bacterium, Streptococcus faecalis. In starving cells, K+ movements into the cells or out are very slow; even 42K+/K+ exchange requires concurrent metabolism of glucose or arginine. Metabolizing cells accumulate K+, establishing a concentration gradient of some 50,000. Accumulation is...

Streptococcus faecalis proton gradients and tetracycline transport.

The transport of chlortetracycline by Streptococcus faecalis is energy dependent. Addition of glucose to energy-depleted cells enhances both the transport rates and accumulation levels. Transport rates can be altered independently of glucose by treating cells with ionophores that increase or decrease the proton gradient. The transport of the antibiotic is linked only to the transmembrane pH dif...

Characterization of two peptide-transport systems in Streptococcus faecalis.

Transport of aminophosphonic acids in Lactobacillus plantarum and Streptococcus faecalis.

Aminophosphonic acids analogous to glutamic acid, aspartic acid, alanine, and valine were actively accumulated by Lactobacillus plantarum. Uptake was dependent on the availability of glucose and, in all cases, the estimated intracellular concentrations substantially exceeded extracellular levels. During uptake, there was little metabolism of tritiated 2-amino-3-phosphonopropionic acid (APP), th...

Hydroxylysine metabolism in Streptococcus faecalis.