Cofactor contents of methanogenic bacteria reviewed
Gorris, L.G.; van der Drift, C.
Biofactors 4(3-4): 139-145
1994
ISSN/ISBN: 0951-6433 PMID: 7916957 Document Number: 431389
The content of specific methanogenic cofactors was assessed for a range of hydrogenotrophic and methylotrophic methanogenic bacteria grown on different substrates using high performance liquid chromatography. In general, all methanogens were found to contain coenzyme F-420 analogues, methanopterin (MPT) analogues and 5-hydroxybenzimidazolylcobamide (vitamin B-12-HBI). In hydrogenotrophic methanogens of the genera Methano-bacterium and Methanobrevibacter, as a rule, coenzymes F-420-2 and F-420-3 as well as MPT were present. Members of the closely related genera Methanospirillum, Methanogenium, Methanoculleus and Methanoplanus contained the same coenzyme F-420 analogues but tatiopterin and/or thermopterin were present instead of MPT. In contrast, methylotrophic methanogens predominantly contained coenzymes F-420-5 and F-420-4, and sarcinapterin (SPT). In Methanolobus tindarius, both MPT and SPT were found, whereas no MPT analogue could be detected in Methanosphaera stadtmanae. In the hydrogenotroph Methanococcus voltae, SPT occurred as the sole MPT analogue. The levels of the various cofactors varied markedly among different methanogens and also for individual methanogens as a function of growth substrate or batch number. A correlation of cofactor levels and substrate utilized was not established. However, with methylotrophic methanogens it was noticed that the ratio of the contents of vitamin B-12-HBI and SPT was independent of growth substrate.