Applied Microbiology and Biotechnology

, Volume 40, Issue 6, pp 898–903

The effect of molybdate and tungstate ions on the metabolic rates and enzyme activities in methanol-grown Methylobacterium sp. RXM

  • Francisco M. Gírio
  • M. T. Amaral-Collaço
  • Margaret M. Attwood
Applied Microbial and Cell Physiology

DOI: 10.1007/BF00173996

Cite this article as:
Gírio, F.M., Amaral-Collaço, M.T. & Attwood, M.M. Appl Microbiol Biotechnol (1994) 40: 898. doi:10.1007/BF00173996

Abstract

Feed-switching experiments were carried out in steady-state methanol-excess chemostat Methylobacterium sp. RXM cultures at a fixed dilution rate, temperature and pH (0.10 h−1, 30° C and 6.95, respectively). The removal of molybdate from the nutrient supply led to a metabolic energy deficiency reflected in the molar growth yield and biomass values. High carbon conversion efficiency was linked with high formate dehydrogenase (FDH) activity and observed only when either molybdate or tungstate was added to the feed medium. A constant coenzyme ratio NAD+/K-ferri-cyanide linked to FDH activity was found during the enzyme stimulation period following the feed-switching experiment with tungstate addition, which suggests that both activities belong to the same enzyme. Quantitative metabolic responses (carbon conversion efficiency, methanol and O2 consumption rates, CO2 production rate and respiratory quotient) were measured in between steady-states just after the shift in the nutrient supply composition.

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • Francisco M. Gírio
    • 1
  • M. T. Amaral-Collaço
    • 1
  • Margaret M. Attwood
    • 1
  1. 1.Department of Molecular Biology and BiotechnologyUniversity of SheffieldSheffieldUK
  2. 2.INETI — Departamento de Tecnologia das Indústrias QuímicasUnidade de Microbiologia Industrial-BiotechnologiaLisboa CodexPortugal