I'm a biology professor and I use cheesemaking in freshman bio labs to teach about enzyme function. As part of this, they get to experiment with changing parameters to see the effect. One of the options I like to give them is changing enzyme type and I offer animal, "vegetable" (I use the quotes because I can't bring myself to call a fungus a vegetable), and GM rennets. I've been using Chymostar but now that my stock is depleted and I need to get more, I find it's unavailable. I know of Chymax and Maxiren, but finding a place to purchase small quantities has been tough. I thought that instead of me spending hours searching, folks here could probably point me in the right direction more quickly.