Switch Bioworks’ Tim Schnabel: ‘We don’t sell fertilizer, we create the thing that makes the fertilizer’

Nitrogen is a crucial nutrient for plants, playing a key role in various vital functions that impact their growth and survival. It is a fundamental component of amino acids, the building blocks of proteins and all life. Nitrogen is also a significant part of chlorophyll, the molecule in plants that gives them their green color and plays a critical role in photosynthesis, allowing plants to use sunlight to produce sugars from water and carbon dioxide. Farmers know that growing healthy crops requires nitrogen fertilizer in one form or another — traditionally, these are mineral or organic fertilizers that supply plants with this much-needed chemical element that stimulates healthy growth, but is there anything else?

According to the Silicon Valley startup Switch Bioworks, there is! It calls itself “the living fertilizer company” and develops microbes that produce sustainable nitrogen fertilizer powered by next-generation synthetic biology. We met with the startup’s Founder and CEO, Dr. Tim Schnabel, to discuss what Switch Bioworks brings to the table for farmers.

FD: Tim, we are so grateful for this opportunity to discuss Switch Bioworks’ transformative technology of making microbes that become sustainable fertilizers. Can you share with our readers how this all works?

TS: Yes, absolutely. As you may know, there are microbes that live on plant roots that have the ability to make ammonia — the most common form of nitrogen fertilizer. In a normal environment, these microbes would not share the ammonia that they make with plants, as they have no reason to do that. It takes a lot of energy to produce ammonia.

At Switch Bioworks, we engineer those microbes so they can start sharing the ammonia they produce with plants. Then, plants can use this ammonia as fertilizer. Our starting points are naturally occurring microbes that we have isolated from fields across the Midwest of the United States and the world.

The product itself will be an inoculum that could be applied at planting, as an in-furrow application or as a seed coating. After planting, the seeds germinate, and the microbes first start making a home for themselves on the plant roots. After a couple of weeks – once established – they start making fertilizer. At the end of the season, the crop is harvested, and you have to apply the product again next year.

Our goal is to replace 25% of nitrogen fertilizer at yield parity with our first-generation products and then 50% with our second-generation products.

FD: Interesting, how do these microbial bacteria work?

TS: Let me explain why we are called Switch Bioworks and what platform we are creating. If you want to make nitrogen fertilizer with a microbe, that process takes energy. If we engineer a microbe to make ammonia for a plant, it will begin to use all of its energy for that process, and it cannot use that same energy for other things that it would normally use it for, like competing with other microbes in the soil or establishing itself on the plant root.

Competition and fertilizer production are similarly important, and since microbes cannot do both things simultaneously, we are separating those processes with a switch. Our microbes are engineered to first colonize plant roots and establish themselves reliably and robustly, and only after that process finishes, they start making fertilizer. We have many different switches that accomplish this task, and we are working on many different types of microbes. These switches are encoded into DNA and activate when the time is right.

What we have done in the first couple of years of the company is develop all of these switches and get proof of concepts in a diversity of microbes. That is essentially our platform: a lot of switches, and a lot of microbes. What we are doing now is putting the best switches into the best microbes, which generates a list of product candidates.

FD: Do you expect farmers to replace fertilizer application practices with your microbes to generate the nitrogen that plants need? Or is your approach capable of supplementing their current workflows?

TS: Our solution does not completely substitute fertilizer use. Instead, it acts as a supplement, which means that you need less conventional fertilizer for the crop to grow to the same yield. There are debates on how much of the traditional fertilizer a biological solution can replace, and we don’t know how high we can push it as of yet. We are starting at 25%, and then our aim is to get to an impressive 50%. So far, we don’t know where the limit is. It will get harder and harder, of course.

It is unlikely we will be able to replace the use of chemical fertilizer completely, but our product works hand in hand with existing farming practices that include the application of chemical fertilizers.

The reason it would be advantageous to replace traditional fertilizer with our microbes is the cost to the farmer. It will be much cheaper to use our product compared to conventional fertilizer. This is mainly because we don’t actually sell fertilizer. We sell the thing that makes the fertilizer, and it is needed in a much smaller quantity — an ounce of powder per acre. That, of course, costs much less than 25-70 pounds of nitrogen.

FD: What markets are you focusing on? Do you focus on any particular crops?

TS: We are initially targeting corn in the U.S., however, the solution we are building is not inherently limited to corn or the US. With more investment, we could build it for other crops and regions.

That being said, I have to mention that if we are working on a new crop in a new region, we might need a different microbial chassis that will be the host microbe. A microbe that does well on corn in Iowa might not do the same on cassava in Kenya. That means that any expansion would require finding the best microbe for that crop in that region. Then, we would have to engineer it to release ammonia. And then it would be a product. That is a lot of work, so for now, we have decided to focus on U.S. corn and some projects in Sub-Saharan Africa to help smallholder farmers.

FD: Why have you decided to focus on corn? What is the market for this crop in the U.S.?

TS: Corn uses the most amount of nitrogen and is a large market. There are 93-94 million acres of corn in the U. S. The only larger market for corn is China with 105 million acres dedicated to this crop. If we can replace 25 to 50 percent of nitrogen fertilizer for U.S. corn, this will turn us into a very successful business – the opportunity is huge.

As a startup, we want to do a lot of things. Opportunities are not just defined by crop type and region, but also by what the microbes are engineered to produce. We could move beyond nitrogen and engineer for phosphate biofertilizer and potentially other properties like biocontrol or biostimulant. However, as a startup, we have to focus so that we don’t run out of funding before reaching revenue. Since we are solving a very complex problem, we want to be careful not to stretch ourselves too thinly by tackling too many things at the same time.

FD: Is it safe to use your microbes instead of traditional fertilizer?

TS: It is important to us that we ensure the utmost safety of our microbes. We have created a huge biobank, hundreds of different microbes that we isolated from corn plants around the world. We put them through a filter that determines whether they are an elite chassis. One of the filter elements is safety. We are working with EPA and USDA to ensure that all of our t’s are crossed and i’s are dotted on safety.

At a later stage, we put selected microbes back onto corn plants under a controlled environment that ensures safety and then measure the plant’s health and the microbe’s colonization of the root. We eliminate microbes that make the plant unhappy and select only those microbes as hosts for our engineering that can colonize the plant strongly, fix nitrogen, and are safe.

FD: Do you already have paying clients, or are you yet in the R&D stage?

TS: Switch Bioworks is in the product development phase. This year, we are testing our nitrogen-generating microbes in greenhouse and field trials. We will continue the trials until we have a sufficient data package to be commercial. Commercialization is still a couple of years away, but we will have our own product in the market.

At the same time, because we have our platform, there is an opportunity to work with other companies. These can be startups, fertilizer producers, or seed companies with which we look to collaborate to improve their products with our switches. Any biological product that produces something will consume energy, and by placing a switch in front of it, we can achieve better colonization and better production. That part of our business model will probably kick off faster, and we already have a lot of interest from potential partners.

FD: Switch Bioworks recently raised a $17M Series Seed round. Was that difficult in the current market turmoil? What will you accomplish with this funding?

TS: Yes, it was hard to raise this money in the currently very challenging market. In fact, we are one of the very few – maybe the only – ag-biotech company that raised a series seed round of this size in 2024. That is a testament to our differentiation, our technology and also the team that we have assembled. We are proud to have experts from all across the world that have come, to work at Switch Bioworks. We also have a very strong syndicate of investors that includes farmers and many funds that deeply care about the planet and human health. We are very grateful for the support we brought around the table with this round.

With the new funding, we plan to expand the platform of switches and microbes and introduce our first-generation products into the field. We also want to start piloting our scale-up production, which will enable us to produce the product for a hundred thousand acres.

FD: Will you need to partner with seed producers to make your technology work on the production scale?

TS: It depends on the application method. If we are talking about the in-furrow application as a liquid that gets sprayed onto the seeds at planting, then about 25% of U.S. farmers will have the necessary equipment. This would allow us to go through the agricultural retail channel. Farmers would purchase the product and then add it as a powder to their in-furrow tank, and then it gets applied.

If it is a seed coat, there are several ways of getting into the field. The first and preferred method would be to work with a seed manufacturer and apply the microbe upstream when the seed is made. That is very difficult from a shelf-life perspective because seed producers expect your product to have a three-year shelf life. Microbe needs to survive on the seed for three years in the presence of other seed coats, such as herbicides, fungicides, or anything else.

Another way to apply the seed coat is to do it right before planting. In this case, farmers would treat the seeds. However, using this method has certain challenges with seed warranty. The seed manufacturers don’t like their seed being coated again before planting because they have already optimized the coat without that process coming over the top.

A third method is using a seed lubricant. As the seeds go through the planter, they get coated with the powder that lubricates them. We could put a microbe in that way, which is an up-and-coming method of applying biological solutions. We are keeping a close eye on that.

We are focusing on the in-furrow method first, as it is an easier and faster route to market, but if you want to get on a lot of acres, you have to come onto the seed.

FD: Based on your experience, what can you recommend to the founders of AgTech startups who have yet to raise their first rounds — what should they focus on, and how should they approach fundraising?

TS: Don’t give up. Start fundraising before you need it, and plan for the raise to take much longer than you think it will. A tough market is a good and rigorous filter that vets technologies with the biggest potential. Be prepared that the pressure of the market will reshape your priorities and your business plan and force you to operate as efficiently as possible. And that is a good thing — uncomfortable but good.

The truth is that we went through about forty different versions of the pitch deck and around ten different versions of the business plan. We ended up at a point where it was much better than it was before. And we found people who really believe in what we are building and its long-term future.

Non-dilutive funding can also help you get further. We have grants from the King Philanthropies and the Gates Foundation that helped us with product development. There are plenty of people who deeply care about food and the planet who are not venture capitalists.

FD: Speaking about the grants from the Bill & Melinda Gates Foundation and King Philanthropies — why did they support Switch Bioworks, and what do you expect from this partnership in terms of R&D and market expansion?

TS: Switch Bioworks’ mission is to feed the world sustainably, and the world is much bigger than just America. The philanthropic funds, for example, are helping us build products for smallholder farmers in sub-Saharan Africa, which is a separate project from the for-profit part of our business. Surprisingly, there are a lot of learnings that benefit both lines of work.

We are super excited to be on those projects. We have traveled to Nigeria, Kenya, Zambia, and Tanzania and learned a lot about the world and what it means to have an impact. We spoke to farmers, and you know, farmers in sub-Saharan Africa apply seven times less fertilizer than in the U.S. If you have a microbe that can make 40 pounds of nitrogen, it makes a huge difference for Africa. You could more than double the amount of fertilizers people have, which will feed forward to increased crop yield, and that really impacts food security.

FD: Summarizing our interview, I would like to ask a personal question: What drives you forward in your journey as the CEO of Switch Bioworks, and why do you think your work is important?

TS: What really supports me is the thought, that my life is a mission to improve the lives of as many people as possible. The problem I picked to solve was fertilizer because it is at the intersection of food and climate.

There are over four billion people on this planet who are reliant on fertilizer to grow enough food to eat. And from a climate standpoint, you know, everyone is affected. Fertilizer production releases over a gigaton of CO₂ equivalent emissions, which is about the same as all cars in America. This makes it a hugely impactful problem.

I also really enjoy the business building aspects, as I have always been a builder. Whether it is a piece of scientific strategy, an important addition to the team, a new company policy, thinking about the company culture, or bringing on a new investor or a strategic partner, all of those things really excite me. I feel like every day, I am adding another piece to the puzzle that I hope, in the end, will improve as many lives as possible.

Sometimes, it means working for 16 hours a day, and I sometimes question myself as to why I keep doing this. The answer I always find is that there is just something in me that keeps it going, and I don’t know who I would be without that flame. Honestly, a lot of things would not be where they are now if it weren’t for a few good people who would just keep working when they could have quit.