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Published July 1, 1994 | metadata_only
Journal Article

Energetic Effect of Vitreoscilla Hemoglobin Expression in Escherichia coli: An Online ^(31)P NMR and a Saturation Transfer Study


A newly developed on-line ^(31)P NMR system has been used to investigate the effect of Vitreoscilla hemoglobin (VHb) expression on the steady-state level of ATP in Escherichia coli under oxygen-limited conditions. The VHb-expressing strain GR021 exhibited a higher growth rate on a minimal fed-batch medium after the onset of oxygen limitation and maintained the same level of ATP pool and transmembrane ΔpH as the slower growing wild-type strain MG 1655, indicating that the net ATP accumulation rate (the rate at which ATP increases per unit volume of culture per unit time) was enhanced in the VHb-expressing strain. Further direct evidence of the enhanced flux of Pi-ATP (catalyzed by ATPase) in GR021 was obtained in a saturation transfer study on respiring cells. VHb-expressing cells respiring on succinate exhibited a P_i-ATP flux 30 ± 5% higher than that of an otherwise isogenic strain that did not express VHb.

Additional Information

© 1994 American Chemical Society and American Institute of Chemical Engineers. Accepted January 7, 1994. This work was supported by the Advanced Industrial Concepts Division of the U.S. Department of Energy and the National Science Foundation (Grant No. BCS 891284). The LH fermentor and instrumentation were generously provided by LH Fermentation (Hayward, CA). R.C. appreciates the assistance of Dr. Boguslaw Kuszta with the saturation transfer experiments.

Additional details

August 20, 2023
August 20, 2023