Carbonic anhydrase 1 is an enzyme that in humans is encoded by the CA1 gene. Carbonic anhydrases are a large family of zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide.
It is becoming more common that the latte macchiato will have a layer of milk foam on the top of the drink as well. A latte is steamed milk, espresso, and a 1/4 inch of foam ontop. It is prepared in this order: flavored syrup (if applicable), espresso, steamed milk, topped with 1/4 inch of foam.
Fior di latte (written also as one word), is made from fresh pasteurized or unpasteurized cow's milk and not water buffalo milk, which greatly lowers its cost. Outside Italy mozzarella not clearly labeled as deriving from water buffalo can be presumed to derive from cow milk.