Scientists Engineer Microalgae to Produce Cheese-Making Enzymes

Researchers at the University of the Punjab in Pakistan successfully harvested functional chymosin, a key milk-clotting enzyme used in cheese production, from microalgae by engineering the chloroplast genome of Chlamydomonas reinhardtii. This method bypasses traditional animal-derived extraction from calf stomach linings, offering a more sustainable, cost-effective, and ethical solution for industrial food manufacturing.

Through the insertion of the bovine cym gene directly into the microalga's chloroplasts, the researchers created a transgenic microalgal strain that is capable of expressing self-activating chymosin, eliminating the extra step typically required to turn prochymosin into chymosin in traditional preparation methods. The resulting recombinant enzyme's ability to curdle milk proteins was subsequently confirmed through standard milk-clotting tests, which demonstrated activity that is comparable to conventional chymosin.

While current volumetric yields remain lower than established industrial fungal platforms, this study provides a foundational framework for scaling up microalgal biomanufacturing. Using a safe and edible microalga offers a sustainable alternative to calf-derived rennet, growing quickly on just light and carbon dioxide while naturally providing extra nutrients like proteins and omega-3 fatty acids.

For more information, read the full study in the World Journal of Microbiology and Biotechnology.