Introducing Sterosaurus

Project Abstract

Our project proposes a novel system that tackles the climate crisis by repurposing carbon dioxide (CO₂) emissions from manufacturing industries, transforming this waste into a valuable resource. Specifically, we utilize CO₂ to fuel algae bioreactors that produce high-value pharmaceutical compounds. By recycling industrial CO₂ and converting it into ergosterols, a precursor of steroid hormones, we create a circular economy model that emphasizes sustainability, innovation, and improved efficiency in pharmaceutical production.

Introduction

Hamilton, Ontario, otherwise affectionately known as “Steeltown” has a rich industrial history, which has sustained our economy for over a hundred years. However, the coal-burning manufacturing needed for steel production makes this a very emissions-intensive process. As we continue our education in this city, we are inspired to find new ways to take advantage of the carbon dioxide emissions and turn waste into wealth.

Project Sterosaurus was developed based on project ChloroNova, which our team, McMasterU, presented at iGEM 2024. ChloroNova proposed the use of algae as a platform for biomanufacturing antimicrobial peptides (AMPs), which have emerged in recent years as a promising alternative to antibiotics that can be used for the treatment of bacterial infections without concern of developing resistance. However, we learned that much of AMP production is rooted in traditional bacterial systems or through chemical synthesis, is highly inefficient and expensive. Our project proposed exploiting the existing machinery for producing AMP in the algal chloroplast, bypassing the need for expensive sugar feed for bacteria or the chemical waste of traditional processes. This project solidified our idea for a biomanufacturing system fuelled by CO₂ that enables the sustainable and decentralized production of high-value bioactive molecules. After receiving ample validation from experts in academia, industry, and at iGEM 2024, our team sought to explore novel applications using algae as a platform for sustainable biomanufacturing.

Building on the knowledge we obtained from our exploration of algae cultivation and engineering last year, we have chosen to pursue the production of a new type of bioactive molecule: sterols. Sterols many applications, including the production of vitamin D2, hormonal therapies, birth controls, and dietary supplements, and more. The demand for sterol-based therapeutics is steadily increasing in Hamilton, and Canada altogether, leading to shortages and rising costs. Different sterols, such as brassicasterol, beta-sitosterol, and ergosterol, are readily produced in algae in relatively small quantities. By engineering the nuclear DNA of algae, we can upregulate the pathway for sterol production in algae. Thus, project Sterosaurus was conceived - our team sought to apply our validated idea for using microalgae as a biomanufacturing platform for the production of ergosterol.

A key focus of our team's recent projects has been optimizing the algae as a biomanufacturing platform through genetic engineering. Due to their robust biological features, algae are a longstanding keystone organism in many biomes, but a very underutilized organism for genetic engineering and sustainable development. The name, Sterosaurus, combines two distinct facets of our project: “stero” as referring to a sterol, the type of lipid of an ergosterol, and “saurus” as a nod to the names of dinosaurs, a period in which algae first colonized and boomed within our world.

Algae is an ideal platform for our purpose as they possess fast growth rates and require minimal resources. Our engineering efforts focus on maximizing both CO₂ uptake and pharmaceutical yield. We have customized our algal strains to efficiently convert CO₂ into targeted bio-products, thereby enhancing overall system performance. Additionally, our system is tailored to match the CO₂ output of local industries in Hamilton, such as breweries, which produce food-grade CO₂ ideal for pharmaceutical applications. This strategic alignment ensures that our process remains not only efficient but also safe and commercially viable.

A 2019 McMaster News article stated, “Big pharma emits more greenhouse gases than the automotive industry… The global pharmaceutical industry is not only a significant contributor to global warming, but is also dirtier than the global automotive production sector” (Belkhir, 2019). Manufacturing companies, for instance, produce large amounts of GHG, which come from heating, ventilation, and other sources. Out of 200 companies that represent the big pharma market, only 25 reported their direct/indirect GHG for the past five years and only 15 reported emissions since 2012. Between automotive and pharma, pharms had 48.55 tonnes of carbon dioxide equivalent/million dollars. This is 55% greater than the automotive sector which sits at 31.4 tonnes CO2 emissions/million dollars. The total global emission from the pharma sector amounted to approximately 52 megatonnes of CO2 in 2015. In the same year, about 46.4 megatonnes of CO2 was generated by the automotive sector. This shows us that despite the pharma market being about 28% smaller than the automotive sector, it pollutes 13% more. This gap becomes even more apparent when examining that just 180 fossil fuel and cement producers are responsible for 60% of humanity’s total emissions from 1850 to 2023.

Environmental Compliance Approval (ECA) consists of a robust full technical review, whereas an Environmental Activity and Sector Registry (EASR) is a self-registration process. As a result, companies fill out the required forms, pay the fees, and are licensed to begin operating. This flexible alternative for companies results in significantly reduced transparency on the regulation the province uses for different companies and industries. Combined with weak enforcement from the ministry, individual facilities can therefore deviate from emission limits and air quality standards, and exemptions are observed to be more common in regions with already poor air quality such as Hamilton.

Unfortunately, the EASR unlike the ECA, has no public comment period, automatically diminishing the voices of those affected by the emission sources. For instance, in Hamilton there are many sites emitting benzene/benzo(a)pyrene, and claim to be operating under site-specific standards. In reality, this means that levels are much higher than set provincial standards, and a lack of power and accountability has made it nearly impossible to enforce regulatory change.

Value creation is central to our mission. By turning industrial CO₂ into a platform for pharmaceutical biosynthesis, we redefine waste as an economic asset, contributing to our circular economy model. Our system produces ergosterols that can be chemically modified into a wide range of steroid hormones, adding flexibility and commercial appeal. Unlike traditional bacterial systems, algae offer post-translational modification capabilities, allowing for the development of customized therapeutics tailored to specific market needs. This adaptability enhances the value proposition for potential industry partners and end users.

The City of Hamilton has developed a robust community energy and emissions plan, aiming to increase industrial efficiency outside of steel mills by 50% from 2016 levels by 2050. At the steel mills, the city hopes to reduce GHG emissions by 50% from 2016 to 2035, and achieve net-zero by 2050. This will likely mean switching from coal to emission-free alternatives like sustainably sourced biochar or green hydrogen.

This has a large impact on the residents from the city of Hamilton as, “three of my family friends have moved out of Hamilton [in the lower city] because of health problems related to breathing concerns” (Morgan, 2023). A study by Health Canada found that the concentrations of benzo(a)pyrene, a known carcinogen, was higher across the entire city than what was set as provincial standards. This was equal to smoking one cigarette a day.

Sustainability is a cornerstone of our initiative. Rather than viewing CO₂ emissions as waste, we reimagine them as a renewable input for valuable production. Our integrated carbon capture system solidifies exhaust CO₂ and delivers it in a usable form for algae cultivation. Through partnerships with local breweries, wineries, and distilleries, we source clean, food-grade CO₂ while promoting community-based industrial symbiosis. We further close the loop by repurposing spent algal biomass as organic fertilizer for local agriculture, contributing to a regenerative, zero-waste ecosystem. Our bioreactor and sequestration technologies are engineered to outperform existing systems in both energy efficiency and output, further reinforcing the sustainability and scalability of our approach.

The Role of Breweries

Between 1990 and 2008, Canadian breweries reduced their CO2 emissions by 200,000 tonnes, and energy efficiency was the main catalyst for this change (Natural Resources Canada). While breweries were not big GHG contributors, improving on-site combustion systems (e.g. boilers, heaters) still helped create a direct and indirect emissions drop. In 2018, research conducted on Ontario Craft Breweries offered more insight into GHG production. Scope 1 of the study highlighted that 14.9% came from direct emissions (natural gas burned on site), Scope 2 that 38.7% was from indirect energy use (e.g. electricity), and 46.4% in scope 3 was from upstream and downstream work (e.g. barley farming, bottle production, transport, etc). The study shows that even small breweries have major indirect emissions, that are often overlooked. The role of breweries is crucial to our project, however, as they produce food-grade CO2 which is ideal for pharmaceutical applications.

From Conceptualization to Implementation

Through our newly developed Human Practices framework (IRUS): we Inquire, Reach out, Understand and Synthesize new and thoughtful information about how our work is built from and impacts our community. We found that major communities in Hamilton lack accessible pharmaceutical care. First, to identify the needs of the Hamilton community, we connected with community members to inquire about how they wanted to see our project integrated in the community and what they wished to come out of these inter-community connections. This educated our Hamilton ethnography analysis, rooting the understanding portion of IRUS. Additionally, we achieved scientific and social validation through symposiums, conversations, town halls, and pitch competitions. By connecting with the government, local city council, and change makers, we addressed barriers to Hamilton, ensuring our project is by the community, for the community.

After identifying gaps, we took it to the lab. After our own research and conversations with pharmacists, we found that the precursor for progesterone, ergosterol, is both a needed pharmacological agent and is naturally produced by algae through the mevalonate (MVA) pathway. We engineer the algae to upregulate the MVA pathway, and in doing so replace the rate-limiting SQS with a homologue SQE to maximize sterol production. Using Golden Gate cloning and Gibson assembly plasmids were transformed into our chassis, Chlamydomonas reinhardtii, to upregulate the MVA pathway.

Our models help integrate our biological plans into the real-life biological functioning of our chassis and improve the scalability of our pilots. Our first financial model represents the financial feasibility of the project and the scalability to profit-margins ratio, representing revenues on a quarterly and annual basis. Our next model is kinetics which projects the metabolic parameters of ergosterol production in C. reinhardtii in MATLAB. This model not only resulted in projected ergosterol production but also explored strategies to accelerate the MVA pathway, which was further integrated into our market reporting and financial modelling. We then modelled the transportation of ergosterols out of the C. reinhardtii using transmembrane proteins, exploring their molecular dynamics using a computer-based simulation. These results found that ergosterols maintain stable binding sites in ergosterol-rich environments, and that this tolerable phenotype is different from typical cholesterol. Lastly ran a flux-balance analysis (FBA) model to improve expression targets. Overall, all of these modelling contributions advance the project beyond our proof of concept and contribute to a feasible and scalable product.

Challenging the Future of Synthetic Biology Education

As students, we are privy to the idea that education shapes how we view the world. A thoughtful and holistic education inspires the scientists of the future, and without a strong educational foundation, it is difficult to demand growth as a society.

Throughout our project, we have worked on reframing how we think of synthetic biology education. From our conversations with lawmakers, students, teachers, and the Ministry of Education, we found a narrow understanding of the topic of synthetic biology.

We promoted learning about the topic through workshops for high school students, classes for elementary students, and symposiums for post-secondary students, to promote the application of synthetic biology to save the world. Hosting the largest synthetic biology event at McMaster, iGEMulate, a case competition, we were able to further carve out a place for synthetic biology at an institutional level. All throughout this outreach, we were gathering feedback from stakeholders to develop a curriculum proposal to further integrate synthetic biology into the Ontario curriculum.

Final Remarks

Our research project exemplifies performance, sustainability, and value through an integrated, circular approach that transforms carbon waste into high-impact pharmaceuticals. By combining advanced genetic engineering, efficient carbon capture, and a deep commitment to environmental stewardship, we offer a scalable solution that redefines both how we manage emissions and how we produce medicine. Our system not only reduces carbon footprints but also adds tangible economic and social value, demonstrating that scientific innovation can simultaneously meet industrial, environmental, and healthcare needs.

Sterosaurus proves that sustainability, efficiency and innovation aren’t separate goals, they are core values of our initiative and the foundation of a new industry.