Which of the following is used as an immunosuppressive agent in organ transplant patients?

Rennin used in the cheese industry is

Identify the correct pair:

With the exception of water,which one of the following is possibly the most important accessory chemical substance in industrial processes?

Assertion: Vitamin $B_2$ is found in cereals,green vegetables,brewer's yeast,egg white,milk,and liver.
Reason: It can be commercially produced by some yeasts.

Which organism is used for the preparation of alcohol?