Acetoclastic methanogenesis needs either the AMP- and ADP-forming acetylcoenzyme A synthetase (Acs and Acd, resp.) or proceeds via acetate kinase and phosphotransacetylase
. In ANME-1, only the alpha subunit of a homologue of Acd was expressed during AOM , but in an ANME-1 proteome of active AOM biomass, no Acd was detected .
The acetyl-CoA is catalyzed by phosphotransacetylase
(PTA) whereas phosphotransbutyrylase (PTB) catlalyzes butyryl-CoA.
Methods--We performed scanning electron microscopy (SEM) to determine structural and quantitative differences in biofilm produced by ackA (encoding acetate kinase), pta (encoding phosphotransacetylase
), ackArcsB (encoding acetate kinase and regulator of capsule synthesis B), ackA-ompR (encoding acetate kinase and outer membrane porin regulator) and ackA-dcuR (encoding acetate kinase and regulator of (C4)-dicarboxylic acid megabolism) mutants, in comparison with their isogenic parent strain.