Methane Eating Microbes – A Novel Solution For Greenhouse Gas Mitigation

Methane is a potent greenhouse gas and a significant contributor to human-driven climate change. It is emitted from a wide variety of sources some of which are fossil fuel-related, but many of which involve microbes. Fortunately many of these are being addressed. There are feed additives that greatly reduce the methane emissions in “cow burps.” Large dairy operations are increasingly installing anaerobic digesters which intentionally use the same microbes that generate problematic methane emissions from manure and use that gas to generate clean energy in the form of electricity or portable sources of renewable natural gas. Other relatively large volume sources of organic materials such food processing waste can also be beneficially handled using anaerobic digestion. For instance there is a company called Bioenergy Devco which is leveraging European technologies to expand the use of digesters for these applications in the US. They recently received a Top Project of the Year Award in the Environment + Energy Leader Awards Program for its bioenergy center in Maryland.

But there are many other sources of methane emissions that have been more difficult to address because they are in settings and at levels for which something as capital-intensive as AD isn’t affordable or practical. These include landfills, compost facilities, smaller animal operations and various types of natural gas leaks. A company called Windfall Bio is pursuing a novel solution for these diverse sources of methane which is based on an interesting category of microbes called “methane eaters.”

Methane Eating Microbes

The technical name for these organisms is methanotrophs and they are actually quite common in nature. They can only get the energy they need to survive and grow from methane or methanol – they can’t use sugars or fats like most other organisms. They can exist under a wide range of conditions as “biofilms” and so they can be put into streams of air containing methane gas on various sorts of filter supports and effectively scrub the greenhouse gas out to “eat” and then “breath out” carbon dioxide. If the methane is from an organic source like manure of food waste, then that CO2 is considered to be “carbon neutral” and if the methane is from a fossil source at least the warming impact is dramatically reduced. Getting rid of the methane is great, but the story is even better because in the process some of these microbes are also able to “fix” nitrogen out of the air and use it as a key nutrient. This is comparable to the way that plants known as “legumes” partner with another kind of microbe to get the nitrogen they need to grow and that can become valuable as a fertilizer. Windfall Bio calls this process “waste to value.”The nitrogen that methane eaters generate and turn into protein can then be turned into a natural, controlled-release fertilizer for crops of any kind, and it is also suitable for precision application methods such as “spoon feeding” through drip irrigation.

There is considerable interest in the potential uses of these organisms. Dr. Mary Lidstrom at the University of Washington is part of a research network developing uses for these organisms and confirms their ecological importance and potentially important role in a variety of methane emissions situation. She does caution that in certain settings where oxygen is limiting some of the organisms involved could produce some nitrous oxide which is an even more potent greenhouse gas – an outcome that could be addressed by insuring adequate aeration.

The scientists at Windfall Bio have identified and patented a particular mix (or consortia) of Methane eating or MEM strains that have the characteristics needed to be deployed in practical solutions for dealing with sources of methane.

Manufacturing is not going to require a large investment because Windfall has successfully worked out how to grow their strains on a contract basis in the existing base of commercial fermentation capacity that is already used to produce everything from bakery yeast to the heme ingredient for Impossible Burgers. The difference is that these microbes are fed methanol instead of sugars. They have also worked out a method to stabilize the bacteria in a dry form for distribution to customers. At this point the economics of producing stable, whole-cell MEMs are promising for a range of potential uses. The company recently announced a $28 million Series A round of investment just one year after a seed round in 2023. There are 9 investor groups involved and the fund is coordinated by Prelude Ventures.

The next step to in the development of solutions for specific methane emission “hot spots” is to put the bacterial mix on a support matrix where they can form their natural biofilm which allows them to be exposed to air containing methane while still being in an environment that is moist enough to allow them to grow. Suitable supports include biochar, tiny glass or plastic beads, or the top layer of a compost pile. Other support materials are certainly possible to fit various situations. In the case of the biochar or compost, the nitrogen fertilizer the bacteria generate is simply part of the final product. With the bead or other reusable supports, the bacteria and associated fertilizer can be washed off for direct use or for drying to make as much as a 15% nitrogen product suitable for commercial mixing and use. The engineering details of any of these uses need to be worked out by experts in each industry.

There are two dimensions to the value created using this technology. The first is something like a “carbon inset” based on the net climate impact of avoided methane emissions and the avoided carbon footprint incurred with synthetic nitrogen fertilizer production using the Haber-Bosch process. The nitrogen fertilizer the MEMs make as they eat the methane has value in and of itself whether it offsets the cost for a farmer at the source or if it is sold to others.

Without any concerted promotional effort, Windfall has already drawn project interest from dozens of players in diverse sectors and geographies. For instance, Whole Foods is interested in using the MEMs to mitigate the manure-related methane emissions from small dairy operations and thus be able to make climate-friendly claims for their milk and other products. Other potential customers include fertilizer manufacturers such as Wilbur Ellis, Amazon AMZN , landfill operators, composting facilities and oil and gas players. At this point the challenge for Windfall Bio is partially how to prioritize cooperative efforts across the many potential applications as they currently have around 25 employees. The recent round of funding will aid in this next interesting chapter.


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