Levi Gadye (2015) gives a history of rennet and the beginnings of fermentation-produced chymosin (FPC).
Rennet was used for thousands of years to make cheese. It is necessary to kill a ruminant animal and remove rennet from its stomach before it begins to eat a plant-based diet. When meat became more popular, and veal less popular, the supply of rennet dropped. FPC was developed as a replacement in the late 1980’s.Pfizer developed FPC by a one-time splicing of the chymosin calf genes into other DNA (CheeseScience.net, n.d.).
Approved by the Federal Drug Administration (FDA) in 1990, “… it produced a more consistent cheese with less waste than an equivalent amount of crude calf stomach extract…An estimated 80 to 90% of cheese in the US and UK is made using FPC” (Gadye, 2015).Despite the fact that it is a byproduct of genetic engineering, FPC contains no living genetically engineered organisms in its finished form. This is the same as human insulin (CheeseScience.net, n.
d.). Thus, fermentation-produced chymosin is difficult to categorize, and why it is part of the genetic engineering debate.