New plant-based method for cheese-making enzyme

The study, recently accepted for publication in Plant Biotechnology Journal, focuses on cyprosin B – a milk-clotting enzyme traditionally extracted from cardoon flowers and used in Portuguese cheese making for centuries. By producing the enzyme in the model plant Nicotiana benthamiana, the researchers achieved high yields of functional cyprosin B and clarified the role of a plant-specific protein domain in its activity and localisation.

– We have demonstrated that plants can serve as efficient biofactories for industrial enzymes, supporting the transition towards greener, non-animal-derived coagulants for the dairy industry, says Saraladevi Muthusamy, first author of the study.

From tradition to innovation

Cardoon flower extracts have long been used in Portugal to make cheeses such as the famous Serra da Estrela. By transferring this traditional knowledge into a plant biotechnology setting, the researchers show how cultural heritage can inspire modern, sustainable innovations for the food industry. 

Using a plant-based expression system instead of microbial fermentation, the researchers achieved yield of up to 81 mg of enzyme per kilogram of fresh leaf tissue, outperforming many existing production systems. 

– This show how important it is to do fundamental research, in this case on protein domains. Now, we are taking this fundamental research to industrial biotechnology, says corresponding author Selvaraju Kanagarajan.

– Just like biocontrol aims to replace pesticides with biological solutions, this work shows how plants can also produce key enzymes for food production. Both approaches reduce dependence on chemical or animal-based inputs, and together they point toward a more sustainable and resilient agriculture. In the future, such plant-based biofactories could also be engineered to produce pathogen- and pest-inhibiting compounds, opening new opportunities for crop protection alongside food and enzyme production, says co-author Ramesh Vetukuri.

Read the scientific article:
Heterologous Production of Cyprosin B in Nicotiana benthamiana: Unveiling the Role of the Plant-Specific Insert Domain in Protein Function and Subcellular Localisation