ENZYMATIC OIL DEGUMMING USING A NOVEL GLYCEROPHOSPHOLIPID:CHOLESTEROL ACYL TRANSFERASE

HAILS, GUILLERMO; CERMINATI, SEBASTIÁN; AGUIRRE, ANDRÉS; ANSELMI, PABLO ARIEL; CASTELLI, MARÍA EUGENIA; PEIRÚ, SALVADOR; MENZELLA, HUGO G.

Congreso; 54th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2018

In the last decades, the need for oils to be used as food and for the production of fuels has been in constant increase. Crude vegetable oils are acomplex mix of triglycerides, phospholipids (or gums), sterols, glycolipids, tocopherols, free fatty acids, metallic traces and other minorcompounds. The refining of oil involves many steps, including the removal of phospholipids (also known as oil ―degumming‖), which causes themajor losses in the industrial process of oil refining. Thus, degumming is an important issue that needs to be addressed with cost effectivemethods. Traditionally, physical and chemical methods have been used. More recently, developments were made to use enzymatic degumming,which possess several advantages over chemical and physical processes. Enzymatic degumming has been employed using a wide variety ofenzymes to hydrolyze phospholipids, generating products that are more easily removed by centrifugation. The most common enzymes used arephospholipase C (PLC) and phospholipase A (PLA), which reduce the phospholipid content and leave less oil trapped by the gums. Thus, uponenzymatic treatment the overall yield increases, which represents a significant economic benefit for the oilindustry.Glycerophospholipid:cholesterol acyl tranferases (GCAT) are enzymes that attack acyl groups from phospholipids just like PLAenzymes. However, they additionally transfer the acyl group to a free sterol, reducing the amount of free fatty acids in treated oil.In this work, 6different GCAT candidates obtained from an in silico analysis were evaluated in terms of their expression, thermal stability and ability to removephospholipids using oils with different phospholipid contents, expecting to formulate a new enzyme for oil degumming. A GCAT fromAeromonas enteropelogenes was selected, due to its ability to work at temperatures up to 60 ºC, and to efficiently remove all phospholipids fromcrude oils (1200 ppm of phosphate). These and other features from this GCAT from A. enteropelogenes are described herein.