Circe
Circe is a Boston-based climate biotech, spun out of Harvard's Wyss Institute, that uses proprietary gas fermentation to convert CO2 into carbon-negative oils, butters, sugars, fuels, and plastics for enterprise customers in food, chemical, and fuel manufacturing.
- Company typePrivate
- Founded2021
- HeadquartersBoston, United States
- Headcount11–50
- GTM typeB2B
- OfferingHardware or Manufacturing
What Circe does
Circe is a Boston-based climate biotech company spun out of Harvard University's Wyss Institute in 2024 that uses proprietary gas fermentation technology to convert point-source CO2 emissions into high-value industrial molecules. Its core platform employs genetically engineered microorganisms that consume CO2 and hydrogen to produce drops-in such as oils, butters, sugars, fuels, and plastics, with water as the primary byproduct; the company claims each kilogram of product removes roughly 3 kilograms of CO2. The technology is licensed exclusively from the Wyss Institute, and Circe operates what it describes as the world's most advanced aerobic gas fermentation pilot facility in Waltham, Massachusetts, which opened in late 2024 with support from the U.S. Department of Energy.
Circe sells carbon-negative molecules to enterprise customers in three primary verticals: food manufacturers seeking sustainable fats and oils, chemical manufacturers seeking lower-carbon feedstocks, and fuel producers exploring low-carbon fuel alternatives. The company states it achieves price parity with incumbent solutions by leveraging abundant low-cost CO2 feedstock. Its go-to-market is direct enterprise sales and partnership-driven pilot collaborations, supported by a single-website marketing footprint and outreach to industry partners. Distribution is single-country/domestic through the Waltham pilot facility.
The business model is a pre-revenue, B2B hardware-and-molecule sale model transitioning from pilot to commercial supply. Circe has raised approximately $14.5 million across multiple 2024 funding events from investors including Bee Partners, Elementum Ventures, Ponderosa Ventures, ReGen Ventures, Undeterred Capital, Climate Capital, Exceptional Ventures, Safar Partners, and the Mass. Manufacturing Innovation Initiative. The company is led by co-founder and CEO Shannon Nangle, with a headcount in the 11–50 range and headquarters in Boston, Massachusetts.
Circe firmographics
Firmographics- Name
- Circe
- Legal name
- Circe
- Website
- https://circebioscience.com
- Company type
- Private
- Founded year
- 2021
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- Circe is a Boston-based climate biotech, spun out of Harvard's Wyss Institute, that uses proprietary gas fermentation to convert CO2 into carbon-negative oils, butters, sugars, fuels, and plastics for enterprise customers in food, chemical, and fuel manufacturing.
- Ownership category
- akta.pro rank
Circe industry classification
Industry- Product category
- Industrial Biotechnology / Carbon-Negative Ingredient Manufacturing
- NAICS
- Basic Chemical Manufacturing (3251), Other Basic Organic Chemical Manufacturing (32519), Chemical Manufacturing (325)
- akta.pro primary industry
- C1 & Synthesis Gas Derivatives (Methanol, Formaldehyde, Acetic Acid) (IMAEADAC)
Keywords
Where Circe is headquartered
LocationHeadquarters
- HQ city
- Boston
- HQ country
- United States
- HQ region
- North America
Offices2 records
Markets served
Circe business model
Business model- GTM type
- B2B
- Offering type
- Hardware or Manufacturing
- Cost components
- Technology or R&D, Operations, Personnel, Infrastructure, Supply Chain
Revenue model
- Carbon-negative Molecule Sales: Circe produces and sells carbon-negative molecules (fats, oils, and other chemicals) manufactured via gas fermentation. The company targets industrial customers in food, chemical, and fuel manufacturing sectors who need sustainable ingredient alternatives.
Go-to-market motion1 record
Distribution channels1 record
Marketing channels2 records
Circe product offering
Product offeringCore offering
Circe manufactures and sells carbon-negative molecules — including oils, butters, sugars, fuels, and plastics — produced via proprietary gas fermentation that converts CO2 and hydrogen into high-value chemicals using engineered microbes. The company sells these drop-in ingredient equivalents directly to industrial manufacturers in the food, chemical, and fuel sectors, removing 3 kilograms of CO2 per 1 kilogram of product produced.
Product overview
Circe operates a modular gas fermentation platform that transforms CO2 into high-value molecules through a proprietary biological manufacturing process. The platform combines biology and chemistry to deliver both precision and scalability—creating complex, tailored products at scale directly from CO2. The company's product portfolio includes five core offerings: Oils, Butters, Sugars, Fuels, and Plastics. These products serve as drop-in, on-spec equivalents to traditionally manufactured ingredients, enabling manufacturers to reduce supply chain costs while meeting environmental targets. The platform is industry-agnostic with applications across food, chemical manufacturing, and sustainable fuel production. The process removes 3 kilograms of CO2 per 1 kilogram of product.
Differentiator
Problem solved
Functional benefit
Products and services
- Oils Carbon-negative oils produced via gas fermentation using CO2, water, and electricity as feedstocks, serving as sustainable, drop-in alternatives to traditionally manufactured oils for food, chemical, and industrial manufacturers.
- Butters Sustainable butter alternatives produced through gas fermentation, including fats like milkfat and palm oil equivalents, created by engineered microbes consuming greenhouse gases; serves food manufacturers seeking drop-in fat ingredients.
- Sugars Carbon-negative sugars produced via gas fermentation, providing sustainable alternatives for food and chemical manufacturing applications where traditional sugar feedstocks are required.
- Fuels Biofuels produced through gas fermentation technology that absorbs CO2 during production, offering sustainable fuel alternatives that reduce industrial carbon emissions for fuel producers.
- Plastics Biodegradable plastics produced via carbon-negative manufacturing processes that utilize CO2 as a resource, providing sustainable alternatives to carbon-intensive chemical manufacturing.
Quantifiable outcome
- 3 kg CO2 removed per 1 kg product produced
Companies that use Circe
Customer profileSegments3 records
Ideal customer profiles3 records
Circe technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature3 records
Circe partnerships and signals
Strategic signalPartnerships
One partnership is on record.
- Harvard University Wyss InstitutecoreExclusive licensing agreement with Harvard's Wyss Institute to commercialize gas fermentation technology. The technology uses microbes to eat greenhouse gases and produce valuable products. This is the foundational technology upon which Circe's business is built.
Scale indicators3 records
Recent moves8 records
Expansion highlights4 records
Circe competitors and assessment
Company assessmentMarket position
Competitive moat4 records
Key highlights6 records
Customer concentration
Circe financial estimates
Financial estimateRevenue estimate
Valuation estimate
Circe leadership team
Management profileNumber of profiles
Profiles1 record
Circe funding detail
Funding detailFunding overview
Funding rounds5 records
Investors9 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Circe M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Circe
What does Circe do?
Circe manufactures and sells carbon-negative molecules — including oils, butters, sugars, fuels, and plastics — produced via proprietary gas fermentation that converts CO2 and hydrogen into high-value chemicals using engineered microbes. The company sells these drop-in ingredient equivalents directly to industrial manufacturers in the food, chemical, and fuel sectors, removing 3 kilograms of CO2 per 1 kilogram of product produced.
Is Circe a public or private company?
Circe is a private company. It is classified as venture growth investor backed and is currently operating.
When was Circe founded?
Circe was founded in 2021. It employs 11 to 50 people.
Where is Circe based?
Circe is headquartered in Boston, United States, in the North America region.
How does Circe make money?
One revenue line is on record: carbon-negative Molecule Sales.
Does Circe have an API?
No public API is recorded for Circe.
What industry is Circe in?
Circe's product category is Industrial Biotechnology / Carbon-Negative Ingredient Manufacturing. Its primary akta.pro industry code is IMAEADAC, C1 & Synthesis Gas Derivatives (Methanol, Formaldehyde, Acetic Acid). Its NAICS code is 3251.