ENZYMES CONCERNED WITH DIGESTION OF LIPIDS 13 



Kvamme el aL 68 reported that wheat-germ lipase is inhibited by concen- 

 trations of sodium 2,4-dichlorophenoxyacetate greater than 0.009 M; 

 this inhibition was shown to be 400 times as effective with castor-bean 

 lipase as with that from wheat germ. 68 The primary type of inhibition was 

 shown to be noncompetitive. Longenecker 69 has reviewed the earlier litera- 

 ture on plant esterases, and Sullivan 70 has summarized the information on 

 the relationship of esterases to milling and baking. 



f. Lipases in Molds and Bacteria. The presence of lipase has been 

 noted in molds, such as the saprophytic fungus (Aspergillus niger 71 ) and in 

 yeasts. 35 Shipe 72 found that the lipases produced by Aspergillus niger (A) 

 and the green cheese mold (Penicillium roqueforti) (P) are quite distinct. 

 Thus, the ^.-lipase hydrolyzed tricaprylin, tributyrin, tricaproin, and tri- 

 propionin, in decreasing order, while the order of activity of the P-lipase on 

 these triglycerides was tributyrin > tricaproin > tricaprylin > tripropionin. 

 Neither of these lipases was able to hydrolyze triacetin. The optimum pH 

 was 5.0 to 5.5 for both enzymes, while the optimum temperatures were 30 

 to 35°C. for P and 35 to 40°C. for A. Calcium chloride accelerated the 

 action of both enzymes, while both were inhibited by acetone, ethanol, 

 formaldehyde, dioxane, toluene, and diethyl ether, although not to the 

 same degree. Ramakrishnan and Banerjee 73 were able to prove the pres- 

 ence of lipase in the green mold found in dairy products (Penicillium chrys- 

 ogenum Si), which had been grown on sesame (Sesamum indicium). In this 

 case, the optimum pH was found to be 6.2 to 6.8. The lipase was able to 

 effect the synthesis of w-butyl oleate. In the case of the lipase from the 

 saprophytic "imperfect" fungus, which causes flax wilt (Fusarium lini 

 Bolley), Fiore and Nord 74 reported an optimum pR of 7.0 at 37°C. This 

 enzyme was found to be intracellular. It was very stable in the dry state, 

 but unstable in aqueous solution. There was no dissociable prosthetic 

 group. The instability in water was believed to be due to proteolysis. 

 This Fusarium lipase was shown to be capable of hydrolyzing triacetin. 

 Yeast lipase has been reported to have an optimum pH of 6.6 to 6.8, and an 

 optimum temperature of 30° C. 75 



68 C. J. Kvamme, C. O. Clagett, and W. B. Treumann, Arch. Biochem., 24, 321-328 

 (1949). 



69 H. E. Longenecker, '"Esterases," in J. A. Anderson, ed., Enzymes and Their Role 

 in Wheat Technology, Chap. IV, Interscience, New York and London, 1946, pp. 127-152. 



70 B. Sullivan, "Esterases in Relation to Milling and Baking," in Enzymes and Their 

 Role in Wheat Technology, Chap. V, 153-174. 



71 R. Schenker, Biochem. Z., 120, 164-196 (1921). 



72 W. F. Shipe, Jr., Arch. Biochem., 30, 165-179 (1951). 



73 C. V. Ramakrishnan and B. N. Banerjee, Arch. Biochem., 37, 131-135 (1952). 



74 J. V. Fiore and F. F. Nord, Arch. Biochem., 26, 382-400 ( 1950). 



75 C. Gorbach and H. Giintner, Monatsh., 61, 47-60 (1932). 



