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Food Lipids: Chemistry, Nutrition, and Biotechnology

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Table 3 Selectivities of Multiple Extracellular Lipases from Geotrichum Species/Strains <strong>and</strong><br />

Mucor miehei<br />

Fungus/strain<br />

Molecular<br />

mass (kDa) Selectivity Ref.<br />

Hydrolysis<br />

G. c<strong>and</strong>idum ATCC 34614<br />

Lipase I 50.1 No preference for C18:1 15<br />

Lipase II<br />

G. c<strong>and</strong>idum CMICC 335426<br />

55.5 No preference for C18:1<br />

Lipase A 53.7 Preference for C16:0 relative to C18:1� 9<br />

Lipase B<br />

G. c<strong>and</strong>idum ATCC 66592<br />

48.9 Selectivity for fatty acids with cis-9 double bond<br />

Lipase I 61 Hydrolyzed C16:0 methyl ester at 60% of initial 126<br />

velocity of that of C18:1 methyl ester<br />

Lipase II 57 Hydrolyzed C16:0 methyl ester at initial velocity<br />

that was only 7% of that of C18:1 methyl<br />

ester<br />

G. c<strong>and</strong>idum ATCC 34614<br />

Lipase I 64 Showed high preference for triolein <strong>and</strong> TAG<br />

with C-8<br />

Lipase II 66 Same as lipase I<br />

Geotrichum sp. F0401B<br />

Lipase A 62 Incompletely 1,3-specific toward triolein but<br />

able to hydrolyze at 2-position at slower rate<br />

Lipase B — Nonspecific positional specificity (presumed<br />

mixture of A <strong>and</strong> C)<br />

Lipase C 58 Incompletely 2-specific<br />

Synthesis<br />

G. c<strong>and</strong>idum NRRL Y-553 Reactivities slow for �-linolenic <strong>and</strong> ricinoleic<br />

acids relative to oleic acid; oleic acid<br />

esterifies 2.5 times faster than C16:0 to 1butanol,<br />

but 50 times faster with 2-methyl-1propanol<br />

or cyclopentanol<br />

to tributyrin <strong>and</strong> triolein 9131). Also, substitution of Thr 83 , which is believed to be<br />

involved in oxyanion binding, with Ala eliminated activity.<br />

At least five genes encoding lipases have been found in C. cylindracea (rugosa),<br />

but the individual isoforms have not been purified <strong>and</strong> had their specificities<br />

determined (132). Based on gene sequences, the lipase genes of C. cylindracea <strong>and</strong><br />

G. c<strong>and</strong>idum appear to belong to the cholinesterase family.<br />

E. Immobilization<br />

One of the limitations to the industrial uses of lipases is cost effectiveness. This can<br />

be improved by reuse of the lipase which can be accomplished by immobilizing the<br />

enzyme on an inert support. Immobilized lipases have been studied for hydrolytic<br />

(12,43,133–138), synthetic (139–143), <strong>and</strong> inter-/transesterification (144–147) reactions<br />

in both aqueous <strong>and</strong> organic media. Materials tested as solid supports for<br />

Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.<br />

127<br />

128<br />

129

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