According to FAO 2023, livestock accounts for about 12% of global anthropogenic greenhouse gas emissions (around 6–8 Gt CO₂-eq).
Among them, ruminants (cattle, sheep, buffalo) are the main contributors, with cattle alone responsible for 62%.
Most of these emissions come from methane released during enteric fermentation and manure management.
Dairy farming is a major branch of livestock production. Milk is not only a vital source of human nutrition but also deeply tied to health, culture, and daily life.
However, the high emissions of conventional dairy are drawing increasing concern. While plant-based milks (such as oat, soy, and almond) offer alternatives, they still fall short in protein quality and nutritional profile, making it difficult to fully replace dairy.
In recent years, microbial milk has emerged as a promising solution.
Through synthetic biology and genetic engineering, microbes can be designed to produce the key milk proteins—caseins and whey proteins—paving the way for sustainable dairy alternatives.
We focus on A2 β-casein. Unlike the common A1 variant, A2 does not generate BCM-7 during digestion, and BCM-7 is linked to intestinal inflammation and digestive discomfort.
Thus, A2 is regarded as a healthier and more gut-friendly option, driving the rise of A2 milk as a growing trend in the dairy market.
We employ our in-house developed PGASO platform (Promoter-based Gene Assembly and Simultaneous Overexpression), which enables multi-gene integration in a single step.
Using this system, we introduced the A2 β-casein gene (CSN2) from Bos taurus and Bos mutus into Kluyveromyces marxianus (KM) yeast, together with the RubisCO carbon fixation pathway. This allows yeast to recycle CO₂ released during metabolism into sugars. The design not only helps reduce emissions, but also increases yield and lowers sugar consumption, contributing to a more sustainable dairy industry.
🌿 Bridging Science with Society
From classrooms to boardrooms, we’ve taken our project beyond the lab. By engaging with students, educators, and experts, we explored how synthetic biology can meet real-world needs — from climate action to market innovation.
Through outreach and interviews, we gained insight into how sustainable dairy intersects with carbon credits, artificial fixation, and the future of food.
Read MoreTestimonial
"The value of carbon reduction lies not only in technical achievement, but in whether it can be recognized and measured by society and industry. For innovations like cow-less milk, quantifiable impact, energy efficiency, and transparent methodology are key to accessing carbon credit systems and gaining public trust."
Have a question or want to learn more about our Project? Get in touch with our team to explore potential collaborations, research partnerships, or funding opportunities.
igemteam@email.nchu.edu.tw
+886 - 422840416 # 404
Biotechnology Center
National Chung Hsing University
Taiwan