Biochemical Engineering Fundamentals, Part 1 - Bailey J., Ollis D. 1989

Applications of enzyme-catalyzed reactions
Applications of hydrolytic enzymes
Applications of esterases

Enzymes of this group cleave ester bonds to form an alcohol and an acid, or catalyze the reverse reaction:

Class="center">R¹COOR^{2 +} Н₂O ⇄ R¹COOH + R²OH

The most important subgroup of esterases are lipases, which hydrolyze fats into glycerol and Fatty acids:

Pancreatic lipase, secreted into the digestive tract after the neutralization of Gastric Acidity, cleaves undigested fats into fatty acids; intermediate Hydrolysis products, mono- and diglycerides, are also formed. As we already mentioned in Ch. 3, the insolubility of high-molecular-weight fats is the reason why lipases exhibit a noticeable catalytic effect only at the Water–lipid interface (see Fig. 3.33).

The Specificity of lipases, as well as that of the second group of esterases, known as aliesterases, is low. Lipases are active in the hydrolysis of high-molecular-weight fats and do not act on fats composed of short-chain carboxylic acids. The latter, on the contrary, are easily hydrolyzed by aliesterases, which are inactive toward high-molecular-weight fats. Lipase activity increases in the presence of Surfactants (such as Bile acids, which stabilize the high specific surface area of fats in emulsions) and Calcium Ions, which apparently bind the resulting fatty acids by precipitation or complexation. The binding of fatty acids removes them from the reaction zone; otherwise, they act as inhibitors.

In aerobic wastewater Treatment processes occurring under natural conditions and used in the activated sludge method (Ch. 14), a constant supply of sufficient oxygen is required to maintain the necessary life forms. Since Oxygen transport through grease films is difficult, The surface of aerated waters in the respective treatment plants must be constantly cleared of such films. The collected liquid, containing large amounts of fats, is then incubated with microorganisms capable of producing extracellular lipases. The formation of oil or grease films over large areas of natural water bodies leads to a sharp decrease in dissolved oxygen concentration, resulting in the death of all microorganisms and more complex life forms unable to exist under anaerobic conditions, unless these organisms can penetrate the lipid layer.

In the meat industry, relatively low-fat meat products can be produced by treating cuts with lipase preparations that cause partial hydrolysis of fats. During food Processing or the treatment of domestic and industrial waste, drains sometimes become clogged with mixtures of insoluble substances containing Proteins, fats, and CARBOHYDRATES. To prevent or clear such blockages, mixtures of proteases, various carbohydrases, and lipases are successfully used.

The second group of esterases includes enzymes called Phosphatases. Phosphatases are essential components of intracellular biosynthetic metabolic pathways that utilize the chemical Free energy released during The oxidation of cellular fuel. There are no data on the Structure/182.html">Practical Application of phosphatases outside living Cells.