Which enzyme helps to make acidic chyme alkaline in nature?

Pancreatic secretions/juices help to make acidic chyme alkaline in nature.

Chyme is the term that is used for the partially digested food mass that has just passed out of the stomach.

Pancreatic juice is secreted by the pancreas, that contains enzymes like amylase, trypsin, lipase and bicarbonate ions for the digestion of carbohydrates and fat.

Whereas,

Bile or gall juice does not contain any types of enzymes. It is a dark-green-to-yellowish-brown fluid formed in the liver and stored in gallbladder aids the digestion of lipids in the small intestine.

Bicarbonate present in the pancreatic juices is responsible for its alkaline nature. This flow of alkaline fluid into the small intestine helps to neutralize the acidic pH of the chyme that comes from the stomach. 

Both bile and small intestinal juice just help in this neutralization.