D-arabino-3-Hexulose 6-phosphate was prepared by condensation of formaldehyde with ribulose 5-phosphate in the presence of 3-hexulose phosphate synthase from methane-grown Methylococcus capsulatus. The 3-hexulose phosphate was unstable in solutions of pH greater than 3, giving a mixture of products in which, after dephosphorylation, allulose and fructose were detected. A complete conversion of d-ribulose 5-phosphate and formaldehyde into d-fructose 6-phosphate was demonstrated in the presence of 3-hexulose phosphate synthase and phospho-3-hexuloisomerase (prepared from methane-grown M. capsulatus). d-Allulose 6-phosphate was prepared from d-allose by way of d-allose 6-phosphate. No evidence was found for its metabolism by extracts of M. capsulatus, thus eliminating it as an intermediate in the carbon assimilation process of this organism. A survey was made of the enzymes involved in the regeneration of pentose phosphate during C1 assimilation via a modified pentose phosphate cycle. On the basis of the presence of the necessary enzymes, two alternative routes for cleavage of fructose 6-phosphate are suggested, one route involves fructose diphosphate aldolase and the other 6-phospho-2-keto-3-deoxygluconate aldolase. A detailed formulation of the complete ribulose monophosphate cycle of formaldehyde fixation is presented. The energy requirements for carbon assimilation by this cycle are compared with those for the serine pathway and the ribulose diphosphate cycle of carbon dioxide fixation. A cyclic scheme for oxidation of formaldehyde via 6-phosphogluconate is suggested.
Skip Nav Destination
Close
Article navigation
December 1974
- Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkAdvertising
Research Article|
December 01 1974
The carbon assimilation pathways of Methylococcus capsulatus, Pseudomonas methanica and Methylosinus trichosporium (OB3B) during growth on methane
T Strøm
;
T Strøm
1Department of Microbiology, University of Sheffield, Sheffield S10 2TN, U.K.
Search for other works by this author on:
T Ferenci
;
T Ferenci
1Department of Microbiology, University of Sheffield, Sheffield S10 2TN, U.K.
Search for other works by this author on:
J R Quayle
J R Quayle
1Department of Microbiology, University of Sheffield, Sheffield S10 2TN, U.K.
Search for other works by this author on:
Biochem J (1974) 144 (3): 465–476.
Citation
T Strøm, T Ferenci, J R Quayle; The carbon assimilation pathways of Methylococcus capsulatus, Pseudomonas methanica and Methylosinus trichosporium (OB3B) during growth on methane. Biochem J 1 December 1974; 144 (3): 465–476. doi: https://doi.org/10.1042/bj1440465
Download citation file:
Close
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Biochemical Society Member Sign in
Sign InSign in via your Institution
Sign in via your InstitutionGet Access To This Article
Cited By
Related Articles
A comparison of the substrate and electron-donor specificities of the methane mono-oxygenases from three strains of methane-oxidizing bacteria
Biochem J (January,1979)
Purification and properties of the methane mono-oxygenase enzyme system from Methylosinus trichosporium OB3b
Biochem J (February,1977)