Manganese acquisition by Lactobacillus plantarum
Lactobacillus plantarum has an unusually high Mn(II) requirement for growth and accumulated over 30 mM intracellular Mn(II). The acquisition of Mn(II) by L. plantarum occurred via a specific active transport system powered by the transmembrane proton gradient. The Mn(II) uptake system has a K/sub m/ of 0.2 ..mu..M and a V/sub max/ of 24 nmol mg/sup -1/ of protein min/sup -1/. Above a medium Mn(II) concentration of 200 ..mu..M, the intracellular Mn(II) level was independent of the medium Mn(II) and unresponsive to oxygen stresses but was reduced by phosphate limitation. At a pH of 5.5, citrate, isocitrate, and cis-aconitate effectively promoted MN(II) uptake, although measurable levels of 1,5-(/sup 14/C)citrate were not accumulated. When cells were presented with equimolar Mn(II) and Cd(II), Cd(II) was preferentially taken up by the Mn(II) transport system. Both Mn(II) and Cd(II) uptake were greatly increased by Mn(II) starvation. Mn(II) uptake by Mn(II)-starved cells was subject to a negative feedback regulatory mechanism functioning less than 1 min after exposure of the cells to Mn(II) and independent of protein synthesis. When presented with a relatively large amount of exogenous Mn(II), Mn(II)-starved cells exhibited a measurable efflux of their internal Mn(II), but the rate was only a small fraction of the maximal Mn(II) uptake rate.
- Research Organization:
- McGill Univ., Montreal, Quebec
- OSTI ID:
- 6264157
- Journal Information:
- J. Bacteriol.; (United States), Vol. 158:1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Cloning, expression, and characterization of cadmium and manganese uptake genes from Lactobacillus plantarum
Overexpression, purification, crystallization and preliminary structural studies of p-coumaric acid decarboxylase from Lactobacillus plantarum
Related Subjects
CADMIUM
UPTAKE
LACTOBACILLUS
METABOLISM
MANGANESE
BIOLOGICAL FUNCTIONS
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
COMPARATIVE EVALUATIONS
OXYGEN
RADICALS
BACTERIA
CHEMISTRY
ELEMENTS
FUNCTIONS
KINETICS
METALS
MICROORGANISMS
NONMETALS
REACTION KINETICS
TRANSITION ELEMENTS
560302* - Chemicals Metabolism & Toxicology- Microorganisms- (-1987)