bacterial synthesis in a sentence

1. Sulfadimethoxine inhibits bacterial synthesis of folic acid ( pteroylglutamic acid ) from para-aminobenzoic acid.
2. Vitamin K2 is from the extensive bacterial synthesis of the vitamin in the intestines.
3. The two important forms are Vitamin K ( phylloquinones ) which occurs naturally in green plants, and Vitamin K2 ( menaquinone ) which is a product of bacterial synthesis in the intestines.
4. It's difficult to find bacterial synthesis in a sentence.