Is gut bacteria Succinivibrionaceae's low methanogenesis understood well enough for GM of cattle gut bacteria to be considered?

Question

After watching the Periodic Table of Videos episode linked in this question I watched the episode Wallabies and Methane where Sir Poliakoff says (a bit after 02:00):

So the point of this paper was that Wallabies have different bacteria in their stomachs, which instead of producing methane, produced succinic acid, which is the diacid of butane.

Succinic acid, Source

The paper he references seems to be Isolation of Succinivibrionaceae Implicated in Low Methane Emissions from Tammar Wallabies Pope, P. B. et al. Science 29 Jul 2011: Vol. 333, Issue 6042, pp. 646-648 DOI: 10.1126/science.1205760

Question: I can not understand the abstract, and the paper is paywalled. Presumably much more work has been done since its publication in 2011. How well is Succinivibrionaceae's low methanogenesis understood; well enough for the genetic modification of cattle gut bacteria to be considered?

Abstract

The Tammar wallaby (Macropus eugenii) harbors unique gut bacteria and produces only one-fifth the amount of methane produced by ruminants per unit of digestible energy intake. We have isolated a dominant bacterial species (WG-1) from the wallaby microbiota affiliated with the family Succinivibrionaceae and implicated in lower methane emissions from starch-containing diets. This was achieved by using a partial reconstruction of the bacterium’s metabolism from binned metagenomic data (nitrogen and carbohydrate utilization pathways and antibiotic resistance) to devise cultivation-based strategies that produced axenic WG-1 cultures. Pure-culture studies confirm that the bacterium is capnophilic and produces succinate, further explaining a microbiological basis for lower methane emissions from macropodids. This knowledge also provides new strategic targets for redirecting fermentation and reducing methane production in livestock.

Answer 1

Old question, but: it's worth noting that there is substantial variation in methane emissions even among ruminants such as cattle. And indeed, even among cattle, Succinovibrionaceae are associated with lower methane emissions. So quite possibly you don't need to do any engineering, though there are apparently a large number of (then) poorly described metabolic genes that might be relevant:

Lower emissions were accompanied by higher Succinovibrionaceae abundance and changes in acetate and hydrogen production leading to less methanogenesis, as similarly postulated for Australian macropods. Large numbers of predicted protein sequences differed between high- and low-methane-emitting cattle. Ninety-nine percent were unknown, indicating a fertile area for future exploitation.

Instead of sorting through all those proteins (which might be fun but would probably take a lot of work), it might be more effective and easier to simply make cattle rumens better places for low-methane bugs to live, if your goal is to reduce methane. Possibly unrelated to these bugs, but for example feeding seaweed to cattle lowers their methane production by affecting their microbiome through antimicrobial activity.

The old adage in microbial ecology is often wrong but always helpful to remember: "everything is everywhere, and the environment selects". So set up an environment that selects for the kind of bug you want!