Sometimes, answering a long-standing question is the question of finding new perspectives.

Take out methane from cows: For years, people have tried to eliminate gas from cattle burrs in an attempt to limit the impact of livestock on the climate. But they are not in trouble yet. This is partly because they look at the problem from the perspective of climate scientists and not farmers.

Kathryn Polkoff, co-founder and CEO of Hoofprint Biome, has been thinking about this issue, just like farmers.

"The first time I heard about this methane problem is Animal Science 101," Polkov, who has a Ph.D. in animal science, told TechCrunch. It is not in the context of climate change, but animal health and productivity.

Polkoff and her co-founder Scott Collins stumbled upon a novel approach that could use enzymes to modify the bovine’s microbiome, cutting methane while promoting the nutrients available to the bovine.

The startup exclusively told TechCrunch that the discovery has earned Hoofprint a $15 million Series A convergence led by SOSV. Other investors involved include Agrizeronz, Alexandria Venture Investments, Amazon’s Climate Commitment Fund, Breakthrough Energy Fellow, Good Growth Capital, Ponderosa Ventures and Twynam. The new round will help the company try out its enzymes on the farm.

"We spent thousands of years breeding animals to make them more efficient and yield, but there weren't really as many attempts to change the microbiome," she said. "It's like you're engineering to drive, but never changing the engine - that's where all the energy comes from."

Hoofprint's feed additives adjust the microbiome in the rumen of cows and inhibit the growth of methane-producing microorganisms, an effective greenhouse gas that warms the planet 84 times and 84 times more than the same amount of carbon dioxide.

Rumen is the “Hodgepodge assembly line”, said Po Bronson, general partner of SOSV. What cows eat are often difficult to digest and extract nutrients from. Over the millennium, cattle evolved with the complex microbiome in the rumen, helping to break down the forage, thereby releasing nutrients in the process.

Cattle will absorb some of these nutrients, but not all of them. Another group of microorganisms steal some of these nutrients to drive their own growth at the expense of cattle, thus producing methane as a by-product. "This is a very specific subset of microorganisms that make methane," Polkov said.

Hoofprint's enzyme inhibits these microorganisms. The startup will use yeast to make enzymes, similar to other industrial enzymes made, including enzymes used in cheeses, detergents and other products.

For Bronson of SOSV, it is a key fact that Hoofprint's enzyme originates from the rumen itself. When a large food company announced trials in the UK in December, Bovaer, a previous methane-reducing product, faced a wave of false information.

He doesn't think Hoofprint will face the same rebound. "The core concept is that their products are a natural protein. They degrade like any other protein that an animal will eat. They are a little natural to the rumen."

Polkoff said Hoofprint’s goal is to increase “feed efficiency” by 5%, or how many pounds a cow can pay for a given feed.

By increasing the efficiency of cow rumen, Bronson is convinced that Hoofprint will be able to succeed with other startups failing farmers. “Knocking down methane is a table bet,” he said. “Making it more productive is what they have to pay.”