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Title: NADH-regulated metabolic model for growth of Methylosinus trichosporium OB3b. Model presentation, parameter estimation, and model validation

Abstract

Chlorinated ethenes, such as the environmental pollutant trichloroethene, can be converted aerobically only via cometabolism. In this process, conversion results from the nonspecificity of oxygenating enzymes. Expression of these enzymes occurs during growth on compounds such as alkanes, aromatics, and ammonia. A biochemical model is presented that described growth of Methylosinus trichosporium OB3b on methane. The model, which was developed to compare strategies to alleviate NADH limitation resulting from cometabolic contaminant conversion, includes (1) catabolism of methane via methanol, formaldehyde, and formate to carbon dioxide; (2) growth as formaldehyde assimilation; and (3) storage material (poly-{beta}-hydroxy-butyric acid, PHB) metabolism. To integrate the three processes, the cofactor NADH is used as central intermediate and controlling factor--instead of the commonly applied energy carrier ATP. This way a stable and well-regulated growth model is obtained that gives a realistic description of a variety of steady-state and transient-state experimental data. An analysis of the cells' physiological properties is given to illustrate the applicability of the model. Steady-state model calculations showed that in strain OB3b flux control is located primarily at the first enzyme of the metabolic pathway. Since no adaptation in V{sub MAX} values is necessary to describe growth at different dilution rates, the organismmore » seems to have a ``rigid enzyme system,'' the activity of which is not regulated in response to continued growth at low rates. During transient periods of excess carbon and energy source availability, PHB is found to accumulate, serving as a sink for transiently available excess reducing power.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Univ. of Groningen (NL)
OSTI Identifier:
20080443
Resource Type:
Journal Article
Journal Name:
Biotechnology Progress
Additional Journal Information:
Journal Volume: 16; Journal Issue: 2; Other Information: PBD: Mar-Apr 2000; Journal ID: ISSN 8756-7938
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; CHLORINATED ALIPHATIC HYDROCARBONS; REMEDIAL ACTION; BIODEGRADATION; GROWTH; NADH2; METABOLISM; METHANE; BIOLOGICAL PATHWAYS; METHANOTROPHIC BACTERIA

Citation Formats

Sipkema, E M, Koning, W de, Ganzeveld, K J, Janssen, D B, and Beenackers, A A.C.M. NADH-regulated metabolic model for growth of Methylosinus trichosporium OB3b. Model presentation, parameter estimation, and model validation. United States: N. p., 2000. Web. doi:10.1021/bp9901567.
Sipkema, E M, Koning, W de, Ganzeveld, K J, Janssen, D B, & Beenackers, A A.C.M. NADH-regulated metabolic model for growth of Methylosinus trichosporium OB3b. Model presentation, parameter estimation, and model validation. United States. https://doi.org/10.1021/bp9901567
Sipkema, E M, Koning, W de, Ganzeveld, K J, Janssen, D B, and Beenackers, A A.C.M. 2000. "NADH-regulated metabolic model for growth of Methylosinus trichosporium OB3b. Model presentation, parameter estimation, and model validation". United States. https://doi.org/10.1021/bp9901567.
@article{osti_20080443,
title = {NADH-regulated metabolic model for growth of Methylosinus trichosporium OB3b. Model presentation, parameter estimation, and model validation},
author = {Sipkema, E M and Koning, W de and Ganzeveld, K J and Janssen, D B and Beenackers, A A.C.M.},
abstractNote = {Chlorinated ethenes, such as the environmental pollutant trichloroethene, can be converted aerobically only via cometabolism. In this process, conversion results from the nonspecificity of oxygenating enzymes. Expression of these enzymes occurs during growth on compounds such as alkanes, aromatics, and ammonia. A biochemical model is presented that described growth of Methylosinus trichosporium OB3b on methane. The model, which was developed to compare strategies to alleviate NADH limitation resulting from cometabolic contaminant conversion, includes (1) catabolism of methane via methanol, formaldehyde, and formate to carbon dioxide; (2) growth as formaldehyde assimilation; and (3) storage material (poly-{beta}-hydroxy-butyric acid, PHB) metabolism. To integrate the three processes, the cofactor NADH is used as central intermediate and controlling factor--instead of the commonly applied energy carrier ATP. This way a stable and well-regulated growth model is obtained that gives a realistic description of a variety of steady-state and transient-state experimental data. An analysis of the cells' physiological properties is given to illustrate the applicability of the model. Steady-state model calculations showed that in strain OB3b flux control is located primarily at the first enzyme of the metabolic pathway. Since no adaptation in V{sub MAX} values is necessary to describe growth at different dilution rates, the organism seems to have a ``rigid enzyme system,'' the activity of which is not regulated in response to continued growth at low rates. During transient periods of excess carbon and energy source availability, PHB is found to accumulate, serving as a sink for transiently available excess reducing power.},
doi = {10.1021/bp9901567},
url = {https://www.osti.gov/biblio/20080443}, journal = {Biotechnology Progress},
issn = {8756-7938},
number = 2,
volume = 16,
place = {United States},
year = {2000},
month = {4}
}