The most viable route to cost-effective production of feed supplements to reduce methane emissions from burping cows remains synthetic chemistry, not large-scale seaweed cultivation, plant extracts, or biomanufacturing, claims Sydney, Australia-based startup Number 8 Bio.
A potent greenhouse gas, methane is produced in ruminants such as cows and sheep in a stomach compartment called the rumen. Here, microbes break down complex carbs to produce carbon dioxide and hydrogen, which are in turn converted into methane by another set of microbes (methanogens) and belched out.
To tackle the problem, startups are exploring everything from supplements made from plant extracts, red seaweed, or a combination of nitrate and a bio-based alcohol (Bovaer), to vaccines, breeding animals that produce less methane, and even editing the genes of the microbes in the rumen.
Strategic pivot
Founded in 2022 by Dr. Tom Williams and Dr. Alex Carpenter, Number 8 Bio originally focused on biomanufacturing: genetically engineering yeast in fermentation tanks to produce methane inhibitors including bromoform, a compound found in red seaweed that interferes with methanogens in the cattle rumen.
But ultimately, even if this sounds simpler than large-scale seaweed cultivation, the economics “don’t really make sense,” even with a strategy of ditching costly downstream purification to extract the bromoform and just selling the dried yeast directly as a feed supplement, said Williams.
“The thing that will be most successful in this market has to be very low cost and very high efficacy. And right now I don’t see how that can be achieved with anything that’s not a synthetic chemical,” said Williams, who was speaking to AgFunderNews after raising a AUD7 million ($4.7 million) seed funding round.
“We got yeast to work quite well in terms of making bromoform and other organohalides that seaweed normally makes. But we basically found that the cost was likely to be too high and it was too difficult to scale up.
“On top of that, there is a clear need in the market for something that’s not bromoform, as there are negative perceptions around it among the public and some corporates. Plus, it seems to us that bromoform alone doesn’t necessarily give rise to a productivity boost for the animals and farmers.”
That said, “My opinion is that several solutions will have to exist because farming is quite diverse,” said Williams. “So I don’t think it’s going to be a case of winner takes all.”
Small molecules
Like fellow startup Volta Greentech, which has recently moved away from seaweed cultivation for livestock methane reduction as the numbers weren’t adding up, Number 8 Bio has turned its attention to methane inhibitors that can be made far more cheaply by third parties via synthetic chemistry, said Williams.
“We screened a whole bunch of things using our invitro rumen platform, as well as in live animals, and found a host of molecules that inhibit methane production. They’re all small molecules, and we outsource their manufacturing to the global chemical industry, but we have intellectual property on their use in ruminants and on the combinations of the ingredients.”
He added: “What we’ve landed on is a non-bromoform synthetic inhibitor which is working quite well, both in terms of methane mitigation and animal productivity. We’ve also been looking at a host of prebiotics that promote the growth of beneficial bacteria in the rumen that can outcompete the methanogens [microbes that produce methane in the animal’s stomach] and lead to the production of nutritious molecules such as volatile fatty acids.”
Novel inhibitor not found in red seaweed
According to Williams, part of the seed funding is for Number 8 Bio to establish a manufacturing facility in Sydney, “basically a warehouse with some simple mixing and managing equipment.”
He added: “One combination we’re looking at is an inhibitor [combined] with some prebiotics. We’re also investigating the use of this novel inhibitor on its own as it appears not to have the negative effects on the rumen that some other inhibitors have.”
The inhibitor in question is “not a haloform [one of several classes of bioactives in red seaweed],” he noted.
Next steps: more testing and validation
Number 8 Bio is continuing to screen potential candidates in its lab “so we have as many shots on goal as we possibly can,” and has now tested “about 15 product variants so far this year in live animals with about the same number remaining [to test] before the end of December,” said Williams.
“From there, we go into larger, longer trials with commercial partners.”
But what kind of reductions in enteric methane has Number 8 Bio been able to deliver with its novel methane inhibitors compared with other players in the market such as Bovaer from dsm-firmenich, which can on average deliver a 30% reduction in enteric methane emissions in lactating dairy cows?
According to Williams, “In a total mixed ration, we can get up to about a 90% reduction, and we’ve achieved that with a few different inhibitors, but it will be different with different delivery formats. So if the cows are getting fed in a milking shed twice daily, the extent of abatements is likely to be lower, for example. Same with a grazing scenario with a lick block.”
Who will pay for livestock methane reduction?
But who will ultimately foot the bill for livestock methane reduction? Farmers, processors, or consumers?
“All of the above,” predicted Williams. “A successful product in this space has to do two jobs. It has to inexpensively and scalably reduce the scope three emissions of a company that cares about that. And second, it has to give a direct productivity benefit to the producer, ideally, I think, with a three to one return on investment relative to the cost of the additive.”
He added: “What we’ve found is that corporates and brands are unwilling to push something onto the farmers that the farmers themselves aren’t enthusiastic about, so both aspects above are really important.”
It’s early days, he acknowledged, “but we have seen productivity increases in some of our trials that would more than cover the cost of the additive. However, we need bigger trials.”
Right now, Number 8 Bio is lining up commercial trials and partnerships in Australia for next year, and should those go well, would be ready for a wider launch in Australia at the end of the year (2025), he said.
“We’re working on some versions of the product that might also have a relatively simple regulatory path in other jurisdictions. We’re also working on products that will have to go through the full FDA type process being marketed in the US.”
Further reading:
ArkeaBio: Vaccination is ‘the lowest cost and easiest to scale’ livestock methane reduction solution
Bovaer is ‘creating a self-sustaining carbon inset market for American agriculture’ says Elanco
