The Complete Genome Sequence of Methanobrevibacter sp. AbM4

Abstract

Methanobrevibacter sp. AbM4 was originally isolated from the abomasal contents of a sheep and was chosen as a representative of the Methanobrevibacter wolinii clade for genome sequencing. The AbM4 genome is smaller than that of the rumen methanogen M. ruminantium M1 (2.0 Mb versus 2.93 Mb), encodes fewer open reading frames (ORFs) (1,671 versus 2,217) and has a lower G+C percentage (29% versus 33%). Overall, the composition of the AbM4 genome is very similar to that of M1 suggesting that the methanogenesis pathway and central metabolism of these strains are highly similar, and both organisms are likely to be amenable to inhibition by small molecule inhibitors and vaccine-based methane mitigation technologies targeting these conserved features. The main differences compared to M1 are that AbM4 has a complete coenzyme M biosynthesis pathway and does not contain a prophage or non-ribosomal peptide synthase genes. However, AbM4 has a large CRISPR region and several type I and type II restriction-modification system components. Unusually, DNA-directed RNA polymerase B′ and B′′ subunits of AbM4 are joined, a feature only previously observed in some thermophilic archaea. AbM4 has a much reduced complement of genes encoding adhesin-like proteins which suggests it occupies a ruminal niche different from that of M1.

Development of Multiwell-Plate Methods Using Pure Cultures of Methanogens To Identify New Inhibitors for Suppressing Ruminant Methane Emissions

“…Prior to inoculation, 0.3 ml of 2.5% Na 2 S · 9H 2 O (wt/vol) was added per 15 ml of medium to ensure sufficient reducing conditions (final concentration, 0.05% Na 2 S · 9H 2 O). Methanobrevibacter species AbM4 was isolated in New Zealand (37,42) and maintained using H 2 and CO 2 at 38°C in either Hungate tubes, Balch tubes, or serum vials using a 5% rumen fluid-based (RM02) medium (11). The medium was supplemented with a mixture of ethanol and methanol (both at 20 mM final concentration) which supported good growth and avoided the necessity for culturing with an overpressure of H 2 and CO 2 .…”

An adhesin from hydrogen‐utilizing rumen methanogen Methanobrevibacter ruminantium M1 binds a broad range of hydrogen‐producing microorganisms

“…smithii PS , Methanobrevibacter sp. AbM 4 and M ethanosphaera stadtmanae MCB ‐3 is publicly available (Fricke et al ., ; Samuel et al ., ; Leahy et al ., 2010; 2013). Draft genome sequences for M .…”

“…The amino acid sequences of putative protein homologues from Methanobrevibacter sp. AbM4 (Leahy et al, 2013), M. smithii PS, Methanobrevibacter sp. D5 (Y. Li, S.C. (Fricke et al, 2006;Samuel et al, 2007;Leahy et al, 2010;.…”

0224 Methane matters: From blue tinged moos, to boozy roos, and for the health of humans too

“…For instance, there are four isolates (and draft genomes) of Methanomassiliicoccus spp. currently described in the literature, recovered in recent years from both the rumen and human digestive tracts (Rea et al, 2007;Leahy et al, 2010;Hansen et al, 2011;Dridi et al, 2012;Leahy et al, 2013). In contrast, the isolation of Methanosphaera stadtmanae DSMZ 3091 T from human feces and Methanosphaera cuniculi DSMZ 4103 T from rabbit feces occurred in the mid-1980s (Miller and Wolin, 1985;Biavati et al, 1988), but very few isolates have since been obtained, and until very recently, genome sequence data was only publically available for the human isolate, leaving this genus significantly under explored.…”