Molybdate reduction by Escherichia coli K-12 and its chl mutants

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.82.1.227· OSTI ID:5830802

Campbell, A M; del Camipillo-Campbell, A; Villaret, D B

During anaerobic growth, Escherichia coli can reduce phosphomolybdate. The reduction can also be carried out by washed cells suspended in buffer at pH 5.7. Phosphate, molybdate, glucose, cells, and anaerobic conditions are required. Reduction is inhibited by 200 ..mu..M chromate, 290 ..mu..M nitrite, 10 mM tungstate, or 20 mM cysteine. Wild-type (chl/sup +/) cells are inhibited by addition of 200 ..mu..M nitrate, but chlA, chlB, and chlE mutants are not. The inhibition of chl/sup +/ cells results from reduction of nitrate to nitrite. This nitrate reduction is not catalyzed by nitrate reductase. Wild-type cells are more sensitive than chl mutants to inhibition by nitrite and cysteine but more resistant to chromate. Pregrowth of chlD cells in 1 mM Na/sub 2/-MoO/sub 4/ increases their sensitivity to nitrite and cysteine, and pregrowth of chl/sup +/ cells in 1 mM Na-MoO/sub 4/ increases their resistance to these agents. Assays of biotin sulfoxide reductase show that the tightness of the chlD block depends on growth conditions; chlD cells grown aerobically in tryptone broth make about 50% as much active enzyme as chl/sup +/ cells, whereas chlD cells grown anaerobically with tryptone plus glucose make less than 10%. The effect of anaerobic pregrowth on the inhibition of molybdate reduction by added nitrate indicates that in vivo nitrate reduction responds to growth conditions in the same manner as biotin sulfoxide reductase does.

• Research Organization: Stanford Univ., CA
• OSTI ID: 5830802
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 82:1; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

560302* -- Chemicals Metabolism & Toxicology-- Microorganisms-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROBIC CONDITIONS
ALDEHYDES
AMINO ACIDS
ANAEROBIC CONDITIONS
AZOLES
BACTERIA
BIOTIN
CARBOHYDRATES
CARBOXYLIC ACIDS
CHROMIUM
COMPARATIVE EVALUATIONS
CYSTEINE
ELEMENTS
ENZYMES
ESCHERICHIA COLI
GLUCOSE
GROWTH
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HEXOSES
IMIDAZOLES
METABOLISM
METALS
MICROORGANISMS
MOLYBDENUM
MONOSACCHARIDES
MUTANTS
NITRATES
NITRITES
NITROGEN COMPOUNDS
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PHOSPHORUS
RESPONSE MODIFYING FACTORS
SACCHARIDES
SENSITIVITY
THIOLS
TRANSITION ELEMENTS
TUNGSTEN
VITAMIN B GROUP
VITAMINS