Cadmium-resistant mutant of Bacillus subtilis 168 with reduced cadmium transport

Journal Article · Sat Jun 01 00:00:00 EDT 1985 · J. Bacteriol.; (United States)

OSTI ID:5118275

Laddaga, R A; Bessen, R; Silver, S

Cd/sup 2 +/ and Mn/sup 2 +/ accumulation was studied with wild-type Bacillus subtilis 168 and a Cd/sup 2 +/-resistant mutant. After 5 min of incubation in the presence of 0.1 ..mu..M /sup 109/Cd/sup 2 +/ or /sup 54/Mn/sup 2 +/, both strains accumulated comparable amounts of /sup 54/Mn/sup 2 +/, while the sensitive cells accumulated three times more /sup 109/Cd/sup 2 +/ than the Cd/sup 2 +/ -resistant cells did. Both /sup 54/Mn/sup 2 +/ and /sup 109/Cd/sup 2 +/ uptake, which apparently occur by the same transport system, demonstrated cation specificity; 20 ..mu..M Mn/sup 2 +/ or Cd/sup 2 +/ (but not Zn/sup 2 +/) inhibited the uptake of 0.1 ..mu..M /sup 109/Cd/sup 2 +/ or /sup 54/Mn/sup 2 +/. /sup 54/Mn/sup 2 +/ and /sup 109/Cd/sup 2 +/ uptake was energy dependent and temperature sensitive, but /sup 109/Cd/sup 2 +/ uptake in the Cd/sup 2 +/-resistant strain was only partially inhibited by an uncoupler or by a decrease in temperature. /sup 109/Cd/sup 2 +/ uptake in the sensitive strain followed Michaelis-Menten kinetics. /sup 109/Cd/sup 2 +/ uptake in the Cd/sup 2 +/ -resistant strain was not saturable. The K/sub m/ and V/sub max/s for /sup 54/Mn/sup 2 +/ uptake by both strains were very similar. Cd/sup 2 +/ inhibition of /sup 54/Mn/sup 2 +/ uptake had an apparent K/sub i/ of 3.4 and 21.5 ..mu..M Cd/sup 2 +/ for the sensitive and Cd/sup 2 +/ -resistant strains, respectively. Mn/sup 2 +/ had an apparent K/sub i/ of 1.2 ..mu..M Mn/sup 2 +/ for inhibition of /sup 109/Cd/sup 2 +/ uptake by the sensitive strain, but the Cd/sup 2 +/ -resistant straian had no defined K/sub i/ value for inhibition of Cd/sup 2 +/ uptake by Mn/sup 2 +/.

• Research Organization: Washington Univ., St. Louis, MO
• OSTI ID: 5118275
• Journal Information: J. Bacteriol.; (United States), Vol. 162:3
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
62 RADIOLOGY AND NUCLEAR MEDICINE
59 BASIC BIOLOGICAL SCIENCES
BACILLUS SUBTILIS
BIOCHEMICAL REACTION KINETICS
CADMIUM 109
UPTAKE
CADMIUM CHLORIDES
MANGANESE 54
MANGANESE COMPOUNDS
INHIBITION
MUTANTS
TEMPERATURE DEPENDENCE
BACILLUS
BACTERIA
BETA DECAY RADIOISOTOPES
CADMIUM COMPOUNDS
CADMIUM HALIDES
CADMIUM ISOTOPES
CHLORIDES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
HALIDES
HALOGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOTOPES
KINETICS
MANGANESE ISOTOPES
MICROORGANISMS
NUCLEI
ODD-ODD NUCLEI
RADIOISOTOPES
REACTION KINETICS
TRANSITION ELEMENT COMPOUNDS
YEARS LIVING RADIOISOTOPES
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