Sources of Lipases

Lipases can be extracted from microbial organisms (bacteria, yeast, and fungi), plants (wheat, oats, corns, and palms), or animals (pancreas, stomach, pharynx, and other tissues) (Taipa et al., 1992). Regardless of the source, most lipases have similar three-dimensional structures and are able to catalyze similar reactions. Nevertheless, they may differ under the same reaction conditions (Yahya et al., 1998). However, Jaeger et al. (1994) showed that there are large differences between amino acid sequences of screened lipases obtained from different sources. 

Supercritical Fluids Technology in Lipase Catalyzed Processes 

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Triacylglycerol lipases (EC 3.1.1.3) are attracting renewed attention since they were demonstrated to be active in organic solvents and to be suitable catalysts in industrial important reactions, such as the synthesis of flavors, emulsifiers, and chiral compounds, and the transesterifi cation of tow-value fats to triacylglycerols of high commercial value. Fbngi are a particularly valuable source of lipases because the enzymes produced by the majority of them are extracellular and readily separable from the mycelia after fermentation. The recent availability of... 

Source of Lipase Laurie acid (mole-%) Oleic acid (mole-%) Non-specificity index... 

Reactor Source of lipase Immobilization method Reference... 

While dairy products may become lipolyzed due to indigenous enzymes, the lipases may also be from outside sources. Bacterial activity, spices, and some fruits contain lipases that may attack the triglycerides of milk. It is relevant that different lipases (different sources) will have a different preference for lipolysis of fatty acids. MiUc lipase and other ruminant sources of lipases tend to preferentially lyse butyric acid from triglycerides. Lipases from Pseudomonas fluorescens and all porcine lipases have little preference for short chain fatty acids. Lipases from molds and Chromobacterium viscosum produce less butyric acid but more capric acid [108]. Lipases that preferentially lyse the short chain fatty acids have a greater impact in the production of off-flavors than do those lipases that lyse the longer chain fatty. 

In the dairy industry, lipases are used in the hydrolysis of milk fat. Applications include flavor enhancement of cheeses, acceleration of cheese ripening, manufacture of cheeselike products, and lipolysis of butterfat and cream. Sources of lipases for cheese enhancement are the pancreatic glands or pregastric tissues of lamb, calf, or kid. Each pregastric lipase leads to its own characteristic flavor pattern, and these enzymes are essential in the production of quality cheeses such as Romano and provolone [15]. Pregastric lipases have also been used for the treatment of calf diarrhea or scours [15] and have potential for the treatment of malabsorption syndrome in children. 

Figure 25-5. Metabolism of high-density lipoprotein (HDL) in reverse cholesteroi transport. (LCAT, lecithinxholesterol acyltransferase C, cholesterol CE, cholesteryl ester PL, phospholipid A-l, apolipoprotein A-l SR-Bl, scavenger receptor B1 ABC-1, ATP binding cassette transporter 1.) Prep-HDL, HDLj, HDL3—see Table 25-1. Surplus surface constituents from the action of lipoprotein lipase on chylomicrons and VLDL are another source of preP-HDL. Hepatic lipase activity is increased by androgens and decreased by estrogens, which may account for higher concentrations of plasma HDLj in women.

Dalmau, E., Montesinos, J.L., Lotti, M. and Casas, C., Effect of different carbon sources on lipase production by Candida rugosa. Enzyme Microb. Technol., 2000, 26, 657-663. 

Polymers derived from natural sources such as proteins, DNA, and polyhy-droxyalkanoates are optically pure, making the biocatalysts responsible for their synthesis highly appealing for the preparation of chiral synthetic polymers. In recent years, enzymes have been explored successfully as catalysts for the preparation of polymers from natural or synthetic monomers. Moreover, the extraordinary enantioselectivity of lipases is exploited on an industrial scale for kinetic resolutions of secondary alcohols and amines, affording chiral intermediates for the pharmaceutical and agrochemical industry. It is therefore not surprising that more recent research has focused on the use of lipases for synthesis of chiral polymers from racemic monomers. 

Finally, the purity-related performance of the enzyme preparation would appear to be a constant throughout a series of measurements. This, however, may not be the case when several enzyme species are present and different activities are expressed as a function of the medium composition [100]. Although it would appear that this source of error is abolished by the present-day availability of highly pure enzyme preparations (but see also [101, 102]), the intrinsic properties of i.e. Upases may lead to different E-values as a result of interfacial activation [103] and the conformation of the lid structure of lipases [56]. 

Modification of nascent chylomicron particles The particle released by the intestinal mucosal cell is called a "nascent" chylomicron because it is functionally incomplete. When it reaches the plasma, the particle is rapidly modified, receiving apo E (which is recognized by hepatic receptors) and C apolipoproteins, The latter include apo C-ll, which is necessary for the activation of lipoprotein lipase, the enzyme that degrades the triacylglycerol contained in the chylomicron (see below). The source of these apolipoproteins is circulating HDL (see Figure 18.16). 

Fatty acids are released from chylomicrons and VLDL by the action of lipoprotein lipase (see pp. 226, 229). However, fatty acids are of secondary importance as a fuel for muscle in the well-fed state, in which glucose is the primary source of energy. 

Bovine blood serum is lipolytically active, but cows producing milk which goes rancid quickly do not have sera that are more lipolytically active than those producing normal milk. Leukocytes, which are present in large numbers in milk, are especially high in mastitic milk they are the source of milk catalase but are apparently not the source of milk lipases (Nelson and Jezeski 1955). 

Jensen, R.G. 1983. Detection and determination of lipase (acylglycerol hydrolase) activity from various sources. Lipids 18 650-657. 

Soon after the initial discovery, it became apparent that neither the source of the enzyme, nor the type of enzyme, nor the type of solvent seem to constrain the use of organic solvents (Zaks, 1986a). Various types of enzymes, such as lipases, proteases (chymotrypsin, subtilisin), oxidoreductases (alcohol dehydrogenase, oxidases, and peroxidases), and others, react in organic solvents. A selection of enzymes... 

We conclude that a commercial immobilized lipase from C. antarctica (Novozym 435) was stable in SCC02 for all experimental conditions investigated. Based on the results obtained here and comparison of them with the results obtained by other investigators, it can be concluded that the magnitude of pressure, temperature, decompression rate, and exposure time needed to inactivate the enzyme strongly depends on the nature and the source of enzyme and, primarily, whether the enzyme is in its native or immobilized form. For the purpose of using this enzyme to catalyze the transesterification reaction of vegetable oils in order to produce esters, the results obtained herein are relevant, because the immobilized lipase can be used with low activity loss at typical conditions of temperature and pressure employed in many biotransformations of raw materials. 

The major source of free fatty acids in the blood is from the breakdown of triacylglycerol stores in adipose tissue which is regulated by the action of hormone-sensitive triacylglycerol lipase (see Topic K4). Fatty acid breakdown and fatty acid synthesis are coordinately controlled so as to prevent a futile cycle (see Topic K3). 

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