Welcome to Boku Viennas iGEM 2023 team page!


This team wants to thank our generous sponsors for making this project possible.

Our sponsors

“Towards an Open-Source Biomanufacturing Protocol of Sex Hormones: Addressing Shortages of Testosterone using Synthetic Biology via De Novo Fermentation of Simple Carbon Sources in the yeast Pichia Pastoris.”

Through our Human Practices work, which involves expert interviews with community biotech labs, patient advocacy groups, biomanufacturing leaders, metabolic engineering experts, and IP professionals; engagement with stakeholders, including the Viennese queer community and biohackers; and writing, revising, and conducting a 55-question professional-grade social science survey distributed globally in three languages (English, German, and Chinese); and our Engineering work, which includes designing modular biobricks and comparing metabolic engineering strategies in yeast, we have verified the crystallization of our ideas into a single thought.

You can use this sentence to explore our work and our ideas.

Or you can read a summary of our project below:

Among the many promising ideas that our team considered this year we were particularly inspired by a 2011 paper from another Austrian research university. The paper, featuring researchers from TU Graz, showed something quintessentially synthetic biology. That the eukaryotic fungal family of organisms known as yeasts could be engineered to stably and efficiently express a sterol from another kingdom of life entirely. Cholesterol, rather than their native Ergosterol.

Cholesterol is a type of lipid molecule called a sterol, and is responsible for the structural stability of the cell membrane. It’s such an important molecule that 13 Nobel Prizes have been awarded to scientists who studied the structure of cholesterol, its biosynthetic pathway, and metabolic regulation. It is the main precursor molecule for all hormones, which make up the 2nd largest class of drugs on the market today, it is the basis for everything from hydrocortisone in anti-itch cream, antihistamines to manage asthma and COPD, to birth control. It’s even a key ingredient in maintaining vaccine stability!

It’s clearly a major pharmaceutical ingredient, but until very recently the only viable source for cholesterol production was from the slaughterhouse. Cholesterol is extracted from bovine gallbladders, often in unsafe and unsanitary conditions, and then chemically treated to extract the valuable cholesterol.

This pressing problem is what initially drew our attention to working with a cholesterol derived product in yeast, and while other researchers have stepped up with potential plant derived cholesterol alternatives we still believe that the process can still be revolutionized with our budding buddies. The killer app that sets our cell factories apart, is that they can do the whole process from simple feedstock to pharmaceutical.

And we couldn’t be aiming for a more timely target than testosterone. According to the Endocrine Society “Hypogonadism (low testosterone) is a common condition in the male population, with a higher prevalence in older men, obese men, and men with type 2 diabetes. It is estimated that approximately 35% of men older than 45 years of age and 30-50% of men with obesity or type 2 diabetes have hypogonadism.”

With an aging population and studies showing a decline in natural testosterone in the western world leading to severe health and quality of life challenges, it's important that we ensure access to this important pharmaceutical.

Leveraging both the literature and the KEGG enzyme database we have constructed and theoretically validated a novel pathway in our host, the model organism Komagataella pastoris. (Formerly Pichia)

We chose this yeast species as a host due to its well characterized genome, biotechnological importance and the deep expertise of supporting BOKU researchers. Boku iGEM has an excellent track record of exciting projects in K. pastoris, including the synthesis of spider silk proteins in 2022, and a complete library of specific promoters and terminators.

We hope to prove through our exploration of this novel process that yeast are capable producers of testosterone and potentially create a platform technology that eventually enables the efficient production of all relevant human hormones.

Producing Steroids in Yeast

skeletal structure of testosterone

Our simplified pathway:

diagram of the metabolic pathway

What is our process?

  • “De novo synthesis of Testosterone in Komagataella phaffii (Pichia pastoris)”

Who is affected by our process

  • Medication against hypogonadism (sub-normal testosterone)
    • Affects both men and women (~12 cases per 1000 people and year)
  • Symptoms worsen / are more prevalent in:
    • Men over 45 (~35%), the Obese / those with Type-2 Diabetes (~30-50%), HIV/AIDS or other chronic health conditions and Pre/Post Menopausal Women
  • Symptoms for adult male hypogonadism include:
    • ED, Reduced Sex Drive and Mood, Lethargy, Difficulty Focusing,Depression, Hot Flashes, Loss of Hair, Loss of Muscle Mass, Loss of Bone Density (possible Osteoporosis), and Infertility

What are the alternatives/existing processes?

  • Cholesterol/phytosterol containing raw materials and waste streams are converted to pharmaceutical grade steroids by Mycobacteria sp.

What are the alternatives/existing processes?

  • No specific starting materials needed - just a simple carbon source
  • One stage fermentation within one organism, no need to process intermediates
  • No hazardous waste streams!
  • No high temperatures or pressures!
  • Fermentation could be performed in a decentralized manner.

What are the disadvantages of our process?

  • Competitiveness dependent on the costs/availability of complex precursors
    • Cholesterol, Phytosterols, Androstenedione, etc