Abstract
Cultures of Methylosinus trichosporium OB3b grown in the presence of very low concentrations of copper synthesize a soluble methane monooxygenase (sMMO) that efficiently catalyzes the oxidation of trichloroethylene and other organic pollutants. Recently, we isolated five M. trichosporium OB3b mutants that express sMMO activity when grown in the presence of elevated copper concentrations (P. A. Phelps, S. K. Agarwal, G. E. Speitel, Jr., and G. Georgiou, Appl. Environ. Microbiol. 58:3701-3708, 1992). Here we show that, in contrast to the results for the wild-type cells, the addition of copper to mutant cultures grown on methane and nitrate as the nitrogen source has no noticeable effect on the growth rate and sMMO expression. In vitro experiments indicated that the copper-resistant phenotype does not arise from an increased stability of sMMO to copper deactivation. Furthermore, the mutant cultures exhibit altered speciation of copper in the extracellular fluid and have substantially decreased levels of cell-associated copper. On the basis of these results, we propose that the mutant phenotype arises from defects in copper uptake and metabolism rather than from changes in sMMO expression or enzyme stability.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2771-2776 |
| Number of pages | 6 |
| Journal | Applied and Environmental Microbiology |
| Volume | 59 |
| Issue number | 9 |
| State | Published - 1993 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biotechnology
- Environmental Science(all)
- Microbiology
Cite this
Phenotypic characterization of copper-resistant mutants of Methylosinus trichosporium OB3b. / Fitch, M. W.; Graham, D. W.; Arnold, Robert G; Agarwal, S. K.; Phelps, P.; Speitel, G. E.; Georgiou, G.
In: Applied and Environmental Microbiology, Vol. 59, No. 9, 1993, p. 2771-2776.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Phenotypic characterization of copper-resistant mutants of Methylosinus trichosporium OB3b
AU - Fitch, M. W.
AU - Graham, D. W.
AU - Arnold, Robert G
AU - Agarwal, S. K.
AU - Phelps, P.
AU - Speitel, G. E.
AU - Georgiou, G.
PY - 1993
Y1 - 1993
N2 - Cultures of Methylosinus trichosporium OB3b grown in the presence of very low concentrations of copper synthesize a soluble methane monooxygenase (sMMO) that efficiently catalyzes the oxidation of trichloroethylene and other organic pollutants. Recently, we isolated five M. trichosporium OB3b mutants that express sMMO activity when grown in the presence of elevated copper concentrations (P. A. Phelps, S. K. Agarwal, G. E. Speitel, Jr., and G. Georgiou, Appl. Environ. Microbiol. 58:3701-3708, 1992). Here we show that, in contrast to the results for the wild-type cells, the addition of copper to mutant cultures grown on methane and nitrate as the nitrogen source has no noticeable effect on the growth rate and sMMO expression. In vitro experiments indicated that the copper-resistant phenotype does not arise from an increased stability of sMMO to copper deactivation. Furthermore, the mutant cultures exhibit altered speciation of copper in the extracellular fluid and have substantially decreased levels of cell-associated copper. On the basis of these results, we propose that the mutant phenotype arises from defects in copper uptake and metabolism rather than from changes in sMMO expression or enzyme stability.
AB - Cultures of Methylosinus trichosporium OB3b grown in the presence of very low concentrations of copper synthesize a soluble methane monooxygenase (sMMO) that efficiently catalyzes the oxidation of trichloroethylene and other organic pollutants. Recently, we isolated five M. trichosporium OB3b mutants that express sMMO activity when grown in the presence of elevated copper concentrations (P. A. Phelps, S. K. Agarwal, G. E. Speitel, Jr., and G. Georgiou, Appl. Environ. Microbiol. 58:3701-3708, 1992). Here we show that, in contrast to the results for the wild-type cells, the addition of copper to mutant cultures grown on methane and nitrate as the nitrogen source has no noticeable effect on the growth rate and sMMO expression. In vitro experiments indicated that the copper-resistant phenotype does not arise from an increased stability of sMMO to copper deactivation. Furthermore, the mutant cultures exhibit altered speciation of copper in the extracellular fluid and have substantially decreased levels of cell-associated copper. On the basis of these results, we propose that the mutant phenotype arises from defects in copper uptake and metabolism rather than from changes in sMMO expression or enzyme stability.
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UR - http://www.scopus.com/inward/citedby.url?scp=0027313433&partnerID=8YFLogxK
M3 - Article
C2 - 8215352
AN - SCOPUS:0027313433
VL - 59
SP - 2771
EP - 2776
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
SN - 0099-2240
IS - 9
ER -