ISSN:
1432-072X
Keywords:
Rhodococcus
;
Propane metabolism
;
Alcohol dehydrogenase
;
Mutagenesis
;
Terminal oxidation
;
Sub-terminal oxidation
;
Western-blotting
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract NAD+-dependent propan-1-ol and propan-2-ol dehydrogenase activities were detected in cell-free extracts of Rhodococcus rhodochrous PNKb1 grown on propane and potential intermediates of propane oxidation. However, it was unclear whether this activity was mediated by one or more enzymes. The isolation of mutants unable to utilize propan-1-ol (alcA-) or propan-2-ol (alcB-) as sole carbon and energy sources demonstrated that these substrates are metabolized by different alcohol dehydrogenases. These mutants were also unable to utilize propane as a growth substrate indicating that both alcohols are intermediates of propane metabolism. Therefore, propane is metabolized by terminal and sub-terminal oxidation pathways. Westernblot analysis demonstrated that a previously purified NAD+-dependent propan-2-ol dehydrogenase (Ashraf and Murrell 1990) was only synthesized after growth on propane and sub-terminal oxidation intermediates (but not acetone), and not propan-1-ol or terminal oxidation intermediates. Therefore, our evidence suggest that another dehydrogenase is involved in the metabolism of propan-1-ol and this agrees with the isolation of the alcA- and alcB- phenotypes. The previously characterized NAD+-dependent propan-2-ol dehydrogenase from R. rhodochrous PNKb1 is highly conserved amongst members of the propane-utilizing Rhodococcus-Nocardia complex.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00276767
