Nutrition and Metabolism of Marine Bacteria XV. Relation of Na ⁺ -Activated Transport to the Na ⁺ Requirement of a Marine Pseudomonad for Growth

Abstract

MATULA, AND ROBERT A. MAcLEOD. Nutrition and metabolism of marine bacteria. XV. Relation of Na+-activated transport to the Na+ requirement of a marine pseudomonad for growth. J. Bacteriol. 92:63-71. 1966.-A marine pseudomonad was found to require 50 to 100 mm Na+ for maximal rate of oxidation of D-galactose and for the transport of D-fucose-H3 into the cells. The same organism required 150 to 200 mm Na+ for the oxidation of L-alanine and for the transport of 4-aminoisobutyric acid-C'4 (AIB-C14) into the cells. Competition studies indicated that D-galactose and D-fucose on the one hand and L-alanine and AIB on the other shared common carriers for transporting the compounds into the cells. This parallelism in Na+ response for oxidation and transport extended to growth whenL-alanine was the sole carbon source in the medium. When D-galactose was the sole carbon source, an amount of Na+ equal to that with L-alanine was needed. KCN and dinitrophenol but not ouabain inhibited the uptake of AIB-C14 by the cells. K+ in addition to Na+ was required for transport, and both Mg++ and either Clor Brwere stimulatory. Photobacterium fischeri was also found to require Na+ specifically for the uptake of AIB-C14 by the cells. All marine bacteria investigated in detail have been found to have a highly specific requirement for Na+ for growth. In this respect, they differ from most terrestrial species examined [see MacLeod (8) for a review]. Previous efforts to MATERIALS AND METHODS Cultures. The organism referred to as B-16 has been classified as a Pseudomonas species type IV and is maintained as culture NCMB 19 at the Torry Research Station, Aberdeen, Scotland. Studies on the 63

Characteristics of an Uptake System for α‐Aminoisobutyric Acid in Leishmania tropica Promastigotes1

“…Paper chromatography of extracts of cells nearly saturated with labeled AIB showed a single peak of radioactivity corresponding to unlabeled AIB. This is in agreement with observations in bacteria (6,23,30), as well as eukaryotic systems including Crithidiafasciculata ( 1 9) and mammalian cells (2,29,31). AIB is nonmetabolizable due to the absence of an a-hydrogen that normally allows tautomeric changes of pyridoxal derivatives necessary for degradation (5).…”

Stability and Comparative Transport Capacity of Cells, Mureinoplasts, and True Protoplasts of a Gram-Negative Bacterium

“…Previous studies with whole cells of this organism have been interpreted as indicating that Na+ has two functions in these cells. One function, which is highly specific for Na+, is involved in the uptake of 14C-AIB (14,37), and the other, which can be carried out at least partially by Li+, prevents the release of the accumulated compound by the cells (37). Since protoplasts and whole cells had the same quantitative requirements for Na+ for uptake of 54C-AIB and since Li+ exerted the same degree of sparing action on the Na+ requirement, it can be concluded that both functions of Na+ are carried out at the level of the cytoplasmic membrane.…”

Taxonomy of Marine Bacteria: the Genus Beneckea

“…This requirement is specific and is independent of an osmotic function since growth does not occur in a medium in which sodium is replaced by equimolar amounts of other monovalent cations (33,34). In the case of two species of marine bacteria, it has been shown that their permease systems require sodium for the uptake of exogenous substrates (17). The sodium ion requirement of many or all bacteria of marine origin has led to the suggestion that this property may serve to distinguish marine bacteria from soil and fresh water strains (33,34).…”