SUMMARY: Oxygen-limited (N-fixing) chemostat cultures of supplied with a N-free medium were established by introducing low atmospheric O concentrations into the gas supply of anaerobic glucose-limited N-fixing chemostat cultures; the molar growth yield for glucose and the efficiency of N fixation (μg N fixed/mg glucose consumed) were increased (by up to 82%) from the anaerobic values.

Acetylene-reducing activity was inhibited reversibly by O in samples from O-limited and anaerobic glucose-limited chemostat cultures. Oxygen uptake rates in samples from these chemostat cultures were similar, but CH-reducing activity in samples from O-limited chemostat cultures was more tolerant of low atmospheric O concentrations, in part because of a higher population density. In the absence of glucose, O was required at a low atmospheric concentration for CH reduction in samples from either O-limited or anaerobic glucose-limited chemostat cultures. The possibility is discussed that ATP generated from oxidative phosphorylation can be used for N fixation in


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error