Related Experiment Video
Updated: Jun 16, 2025

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
Published on: January 7, 2019
Effects of Nitrate on Hydrogenogenic Carbon Monoxide Oxidation in Parageobacillus thermoglucosidasius
Yuka Adachi Katayama1, Yoshinari Imaura1, Masao Inoue1,2,3
1Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
Abstract:
Parageobacillus thermoglucosidasius is a thermophilic facultative anaerobe capable of hydrogenogenic carbon monoxide (CO) oxidation utilising nickel-containing CO dehydrogenase (Ni-CODH) and energy-converting hydrogenase (ECH). Nitrates have been reported to exert promoting or inhibitory effects on the growth of CO oxidizers and acetogens, and these contradictory outcomes obscure the relationship between nitrate and CO oxidation. In this study, we analysed the effects of nitrate on hydrogenogenic CO oxidation and growth in P. thermoglucosidasius NBRC 107763T using wild-type and codh- and/or ech-disrupted strains. The results demonstrated that the addition of 50 mM nitrate suppressed hydrogenogenic CO oxidation while promoting hydrogen-oxidising nitrate reduction and rapid cell growth, resulting in a 2.3-fold higher OD600 than the control. Assays using cell lysates showed that 10 μM nitrate suppressed CO oxidation below the detection limit without affecting hydrogen production, indicating that nitrate affects the CO-oxidising function. These findings imply that CO oxidation in P. thermoglucosidasius is primarily coupled to proton reduction, and deactivated during nitrate respiration. Therefore, hydrogenogenic CO oxidation serves as an auxiliary energy-obtaining mechanism, functioning in the absence of alternative electron acceptors such as nitrate. This study enhances our understanding of CO-dependent energy generation and highlights the supplemental use of CO in P. thermoglucosidasius.
More Related Videos
08:31Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition
Published on: October 3, 2018
08:05Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
Related Concept Videos
Catalysis
Oxygen Transport in the Blood
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
2° Amines to N-Nitrosamines: Reaction with NaNO2
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...