Inhibition of methanogenesis by sulphate reducing bacteria competing for transferred hydrogen

Abstract

A methanogenic bacterial consortium was obtained after inoculation of benzoate medium under N₂/CO₂ atmosphere with intertidal sediment. A hydrogen donating organotroph andMethanococcus mazei were isolated from this enrichment. H₂-utilising sulphate reducing bacteria were isolated under H₂/CO₂ in the absence of organic electron donors. TheMethanococcus was able to produce methane in yeast extract medium under N₂/CO₂ if the H₂ donating organism was present, and sulphate reduction occurred if the hydrogen utilising sulphate reducing bacteria were grown with the H₂ donating organism. The ability of the H₂ utilising sulphate reducing bacteria to inhibitMethanococcus competitively was shown in cultures containing both of these H₂ utilising bacteria.