Inducible and constitutive expression of pMOL28-encoded nickel resistance in Alcaligenes eutrophus N9A

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Journal of Bacteriology; (USA)

OSTI ID:7018129

Siddiqui, R A; Schlegel, H G; Meyer, M ^[1]

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1. Universitaet Goettingen (Germany, F.R.)

The nickel and cobalt resistance plasmid pMOL28 was transferred by conjugation from its natural host Alcaligenes eutrophus CH34 to the susceptible A. eutrophus N9A. Strain N9A and its pMOL28-containing transconjugant M220 were studied in detail. At a concentration of 3.0 mM NiCl{sub 2}, the wild-type N9A did not grow, while M220 started to grow at its maximum exponential growth rate a lag of 12 to 24 h. When grown in the presence of subinhibitory concentrations of nickel salt, M220 grew actively at 3 mM NiCl{sub 2} without a lag, indicating that nickel resistance is an inducible property. Expression of nickel resistance required active growth in the presence of nickel salts at a concentration higher than 0.05 mM. Two mutants of M220 were isolated which expressed nickel resistance constitutively. When the plasmids, pMOL28.1 and pMOL28.2, carried by the mutants were transferred to strains H16 and CH34, the transconjugants expressed constitutive nickel resistance. This indicates that the mutation is plasmid located. Both mutants expressed constitutive resistance to nickel and cobalt. Physiological studies revealed the following difference between strain N9A and its pMOL28.1-harboring mutant derivatives. (i) The uptake of {sup 63}NiCl{sub 2} occurred more rapidly in the susceptible strain and reached a 30- to 60-fold-higher amount than that in the pMOL28.1-harboring mutant; (ii) in intact cells of the susceptible strain N9A, the cytoplasmic hydrogenase was inhibited by 1 to 5 mM NiCl{sub 2}, whereas 10 mM Ni{sup 2+} was needed to inhibit the hydrogenase of mutant cells; (iii) the minimal concentration of nickel chloride for the derepressed synthesis of cytoplasmic hydrogenase was lower in strain N9A than in the constitutive mutant.

• OSTI ID: 7018129
• Journal Information: Journal of Bacteriology; (USA), Journal Name: Journal of Bacteriology; (USA) Vol. 170:9; ISSN JOBAA; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CELL CONSTITUENTS
COBALT
CYTOPLASM
ELEMENTS
ENZYMES
EVEN-ODD NUCLEI
GENE REGULATION
GENETIC ENGINEERING
GROWTH
HOURS LIVING RADIOISOTOPES
HYDROGENASES
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
METABOLISM
METALS
MICROORGANISMS
MUTANTS
NICKEL
NICKEL 65
NICKEL ISOTOPES
NUCLEI
OXIDOREDUCTASES
PLASMIDS
RADIOISOTOPES
TRACER TECHNIQUES
TRANSITION ELEMENTS