Epoxidation and Ketone Formation by C1-Utilizing Microbes

Hou, C. T.; Patel, Ramesh N.; Laskin, Allen I.

doi:10.1016/s0065-2164(08)70329-0

Cited by 35 publications

(9 citation statements)

References 38 publications

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“…Due to their lack of specificity, the soluble methane monooxygenases (MMOs) produced by some type II methanotrophs can initiate degradation of chlorinated volatile organic compounds (VOCs) and aromatic compounds through cometabolism (Colby et al, 1977;Oldenhuis et al, 1989;Tsien et al, 1989). They also possess commercial potential in the production of alkene epoxides, such as propene oxide (Higgins et al, 1980;Hou et al, 1980;Hou, 1984).…”

Section: Introductionmentioning

confidence: 99%

On‐line estimation of dissolved methane concentration during methanotrophic fermentations

Ramsay

2006

Biotech & Bioengineering

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Knowledge of the aqueous phase methane concentration is critical to understanding and controlling process kinetics in methanotrophic bioreactors. Unfortunately since no dissolved methane probe is commercially available, this data must be obtained off-line by the time-consuming gas-liquid partition method. In this study we demonstrate how knowledge of the reactor's k(L)a for oxygen combined with gas phase methane analysis can be used to continuously estimate the aqueous phase concentration of dissolved methane. The on-line estimation was verified in two reactor systems with greatly different values of k (L)a. In both systems the measured and calculated dissolved methane concentrations were in good agreement although dissolved methane was underestimated in both cases. The utility of this methodology was demonstrated by revealing a possible metabolic bottleneck in the model system.

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Section: Introductionmentioning

confidence: 99%

On‐line estimation of dissolved methane concentration during methanotrophic fermentations

Ramsay

2006

Biotech & Bioengineering

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“…[108] Die Hydratase war nicht aktiv gegenüber trans-ungesättigten Fettsäuren wie Elaidinsäure E-1 a und ungesättigten Fettsäuren ohne Doppelbindung in 9-Position wie Erucasäure 3 a. [109] Man erwartet in Zukunft, dass die Proteinstrukturaufklärung bei Algen, höheren Pflanzen und marinen Lebewesen Fortschritte macht und diese Enzyme in Mikroorganismen kloniert werden, sodass Biokatalysatoren in gröûeren Mengen als bisher für präparative Anwendungen zur Verfügung stehen. Da Hydratasen aus einer Vielzahl von Bakterien und Hefen (9Z)-Fettsäuren in 10-Hydroxyfettsäuren umwandeln, kann vermutet werden, dass die C10-Spezifität universeller Natur ist.…”

Section: Mikrobielle Hydratisierungen Ungesättigter Fettsäurenunclassified

Neue Synthesen mit Ölen und Fetten als nachwachsende Rohstoffe für die chemische Industrie

Biermann¹,

Friedt²,

Lang³

et al. 2000

Angewandte Chemie

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“…The enzyme was not linked directly to NADH, but electrons could be transferred from NADH via an electron transport system to the "physiolog- Inhibition of methane monooxygenase activity by the immunoglobulin fraction from antisera prepared against the purified hydroxylase. Various amounts of immunoglobulin fraction from immune and normal rabbit sera were incubated with a constant amount of purified hydroxylase for about 15 min. The immnunoglobulin-treated hydroxylase was used as hydroxylase in the methane monooxygenase assay, and the epoxidation of propylene to propylene oxide was measured.…”

Section: Fig 2 Sds-page Of the Purified Hydroxylasementioning

confidence: 99%

Purification and properties of the hydroxylase component of methane monooxygenase

Patel¹,

Savas²

1987

J Bacteriol

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Methane monooxygenase from Methylobacterium sp. strain CRL-26 which catalyzes the oxygenation of hydrocarbons was resolved into two components, a hydroxylase and a flavoprotein. An anaerobic procedure was developed for the purification of the hydroxylase to homogeneity. The molecular weight of the hydroxylase as determined by gel filtration was 220,000, and that determined by sedimentation equilibrium analysis was about 225,000. The purified hydroxylase contained three nonidentical subunits with molecular weights of about 55,000, 40,000, and 20,000, in equal amounts as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is an a272'y2 protein. Optical absorption spectra revealed peaks near 408 and 280 nm, and fluorescence spectra revealed emission peaks at 490 and 630 nm. The purified hydroxylase contained 2.8 ± 0.2 mol of iron and 0.5 ± 0.1 mol of zinc per mol of protein but negligible amounts of acid-labile sulfide. The antisera prepared against the hydroxylase showed cross-reactivity with hydroxylase components in soluble extracts from other methanotrophs.Methanotrophs, organisms capable of utilizing methane as their sole source of carbon and energy, oxidize methane to carbon dioxide via methanol, formaldehyde, and formate. Higgins and Quayle (14) have presented evidence for an oxygenase step in the utilization of methane by showing that the oxygen in the methanol excreted by cell suspensions of Methanomonas methanooxidans and Pseudomonas methanica is derived exclusively from 1802 and not from water. The role of NADH in the reaction was inferred when oxidation and oxygen consumption catalyzed by the particulate fractions of various methane-utilizing bacteria (10,21,22,27) correlated with NADH oxidation. Tonge et al. (27) partially purified the methane monooxygenase system from particulate fractions derived from the obligate methane-utilizing bacterium Methylosinus trichosporium OB3b, and they concluded that three components are required for activity. Also, Colby et al. (5)(6)(7)(8) and Dalton (9) have described a multicomponent soluble methane monooxygenase from a strain of Methylococcus capsulatus (Bath). Recently we reported that a variety of hydrocarbons are oxidized by cell-free preparations of Methylobacterium sp. strain . We have resolved methane monooxygenase into two components, a hydroxylase and a flavoprotein. This report describes the purification and properties of the hydroxylase component.The methane-utilizing organism Methylobacterium sp. strain CRL-26 was isolated from soil samples by enrichment culture with methane as a carbon source, as described previously (20). The organism was maintained at 30°C on agar plates containing mineral salts (11) in a dessicator under an atmosphere of methane and air (1:1, vol/vol). Strain CRL-26 was grown on methane at 300C in 4.0-liter flasks containing 1 liter of mineral salts medium (11) A600 of 0.5. A gas mixture of 25% methane (containing 2 to 5% carbon dioxide) and 75% air was continuously sparged through the fermentor ...

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Epoxidation and Ketone Formation by C1-Utilizing Microbes

Cited by 35 publications

References 38 publications

On‐line estimation of dissolved methane concentration during methanotrophic fermentations

On‐line estimation of dissolved methane concentration during methanotrophic fermentations

Neue Synthesen mit Ölen und Fetten als nachwachsende Rohstoffe für die chemische Industrie

Purification and properties of the hydroxylase component of methane monooxygenase

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