Open AccessMethanofuran‐b is required for CO 2 formation from formaldehyde by Methanosarcina barkeri
Author(s) -
Mahlmann Andreas,
Deppenmeier Uwe,
Gottschalk Gerhard
Publication year - 1989
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1989.tb03563.x
Subject(s) - methanosarcina barkeri , methanogenesis , formaldehyde , chemistry , electron acceptor , cofactor , methanosarcina , electron donor , catalysis , stereochemistry , photochemistry , methane , organic chemistry , enzyme
Extracts of Methanosarcina barkeri strain Fasaro oxidized formaldehyde to CO 2 with methyl‐coenzyme M as the natural terminal electron acceptor resulting in methanogenesis. A combination of the artificial electron acceptors methylviologen and metronidazole could substitute for methyl‐coenzyme M. The rate of formaldehyde oxidation was thereby increased. Taking advantage of this artificial electron acceptor system the role of cofactors in formaldehyde oxidation was investigated. Cofactor‐free extract of M. barkeri did not catalyze the oxidation of formaldehyde. CO 2 formation could be restored by the addition of tetrahydromethanopterin‐b (H 4 MPT‐b) and methanofuran‐b (MFR‐b) from M. barkeri . Other low molecular weight or heat‐resistant compounds stimulating formaldehyde oxidation were not found. Formaldehyde oxidation seems, therefore, to proceed via H 4 MPT‐b and MFR‐b‐derivatives already shown to be involved in methanogenesis from H 2 + CO 2 .