series of progressive steps, starting with identification of
opportunities for adding functionality to paints and coatings
(see Figure 1). Once a specific market need has been identified, the judicious selection of an appropriate biocatalyst
from nature’s palette of functionalities follows. An assessment of polymer compatibility and functional limits in the
solid state must then be conducted. Finally, formulation of
biocatalytic coatings relative to industry accepted cast/cure
coating standards is required. Let’s discuss how this worked
for Reactive Surfaces’ DeGreez additives.
STEP ONE: IDENTIFY THE MARKET NEED
In recent years, a major effort has been made by coating
manufacturers to develop oil-resistant, self-cleaning coatings
for applications such as optics, electronic displays, kitchen
surfaces and textiles. The use of these coatings would eliminate or reduce the need for corrosive/caustic soaps, detergents and solvents; prevent oil-degradation of coatings and
underlying substrates; and improve odor control and
hygiene. For low oil-load applications, the industry has
offered novel coatings with good roll-off properties and very
high water and oil contact angles to reduce the visual impact
of oil contamination. For high oil-load applications, such as
kitchen surfaces, more traditional protective coatings have
been used that are resistant to penetration/uptake. However,
these surfaces remain difficult to clean without the use of
excessive surfactants or solvents.
An alternative and novel approach is to functionalize coat-
ings with lipid hydrolyzing enzymes from nature, enabling
the auto-decontamination and removal of oil from surfaces.
Lipases (triacylglycerol acylhydrolase, E.C. 3.1.1.3) have
emerged as key enzymes in the biotechnology sector. The
natural substrates of lipases are long-chain triacylglycerols,
which are hydrolyzed by the addition of water across the car-
boxyl ester bonds to liberate fatty acids and glycerol (Figure
2). They are robust and versatile with respect to the range of
substrates they can act upon, while at the same time being
highly specific for the reactions they catalyze. In addition to
their hydrolytic activity on triglycerides, lipases catalyze
esterification, transesterification, acidolysis, alcoholysis and
aminolysis (Table 3). They also exhibit good chemoselectivi-
ty, regioselectivity and enantioselectivity, and as hydrolases
they do not require cofactors. Finally, lipases possess broad
substrate specificity and exhibit optimum activities over a
wide range of temperatures. This versatility makes lipases
important industrial biocatalysts. 4-11
Table 1: Examples of Industrial Enzymes
Industrial/Commercial Application Enzyme(s)
Starch modification: alteration of starch for food, syrups, and industrial use, including fermentation for ethanol production for gasoline blends.
Food industry: Enzymes are used in various food processing and nutrition
enhancement applications.
Pharmaceutical production: enzymes are used in the production of certain antibiotics. penicillin C acylases
