Interactions of cadmium with bacillus subtilis and with natural bacterial populations

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1981

OSTI ID:5336308

Titus, J A

The effects of cadmium on Bacillus subtilis and on natural bacterial populations were examined. Concentrations of cadmium greater than 2 ug/ml were lethal to B. subtilis, but a cadmium-tolerant B. subtilis strain that was selected from the parent strain was not affected by over 10 ug Cd/sup 2 +//ml. The Cd-sensitive strain recovered from lethal concentrations of Cd when the metal-containing medium was replaced with fresh medium and the final growth yield was higher than untreated cultures. The Cd-sensitive strain had a lowered rate of oxygen utilization after Cd exposure, but the oxidation of NADH by a membrane vesicle preparation was not affected by cadmium. Reduction of p-lodonitrophenyl tetrazolium chloride (INT) by the Cd-sensitive B. subtilis showed that lethal levels of Cd had a more pronounced immediate effect of the bacterium's viability than on its ability to respire. Reduction of INT by the Cd-tolerant strain was not affected by Cd exposure. Cadmium adsorption by the sensitive strain showed that most of the Cd was sorbed by the cell wall, followed by the cytoplasm and cell membranes. At 1 ug Cd/sup 2 +//ml the quantity of Cd adsorbed by cell walls and whole cells of the sensitive strain was greater than by the Cd-tolerant strain, but at 10 ug Cd/sup 2 +//ml there was no difference in the quantity of Cd adsorbed. Natural Cd-resistant bacterial populations were examined in the Ottawa River, Lima, Ohio, at a site that had elevated levels of Cd, Cr, Cu, Ni, Zn, and Fe. The percentage of the bacterial population that was resistant to Cd was higher at the metal contaminated downriver site. Bacillus was the most abundant genus of the total river sediment population and Pseudomonas was the most abundant Cd-resistant genus isolated.

• OSTI ID: 5336308
• Country of Publication: United States
• Language: English

Related Subjects

520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
550700 -- Microbiology
560302* -- Chemicals Metabolism & Toxicology-- Microorganisms-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AQUATIC ECOSYSTEMS
BACILLUS
BACILLUS SUBTILIS
BACTERIA
BENCH-SCALE EXPERIMENTS
BIOLOGICAL EFFECTS
CADMIUM
ECOSYSTEMS
ELEMENTS
METALS
MICROORGANISMS
PH VALUE
POPULATION DYNAMICS
PSEUDOMONAS
SEDIMENTS
SENSITIVITY
TEMPERATURE DEPENDENCE