The distribution of 14C in the medium and metabolites of Fusarium oxysporum (an oligotrophic soil isolate) growing with 14C-labelled carbon dioxide in the absence of any exogenous carbon source was determined. Of the fixed carbon, approximately half was released into the medium. Of the carbon remaining in the mycelium, 67% was found in the protein fraction. The distribution of labelled carbon in oligotrophically grown Fusarium oxysporum is comparable to that seen in a number of fungi performing anaplerotic carbon dioxide fixation in the presence of an organic carbon source. Of cell carbon, 0·68% was derived from CO2 under oligotrophic conditions. The specific activity of carbon dioxide assimilation was 259·5 μmol CO2 g−1 dry weight mycelium. Under near oligotrophic conditions (50 mg l−1 C as sucrose), half of the fixed carbon was again released into the medium, and 0·12% of cell carbon was derived from CO2.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Plant Science