Studies of substrate specificities of lipases from different sources

Abstract

Although lipases are widely applied in a wide variety of reactions, available information on the factors that are responsible for the substrate specificities of lipases from different sources is scarce. In this paper, nine lipase-producing microorganism strains were isolated from oil-containing samples. The properties of these enzymes, including pH optima, temperature optima, thermal stability, and pH stability, vary significantly with the different sources from which these lipases were isolated. The substrate specificities of the nine lipases, including fatty acid and positional specificities, were also studied. The fatty acid specificities of the nine lipases were observably different toward 15 substrates with different carbon chain lengths, different saturation degrees and different side chains. The lipases from S 3 Penicillium citrinum (PCL), MJ 1 Aspergillus niger (ANL), MJ 2 Aspergillus oryzae (AOL), YM Bacillus coughing (BCL), S 9 Geotrichum candidum (GCL), and S 11 Candida lypolytica (CLL) showed the strongest specificities to short-chain esters, and the other lipases showed strong selectivity for medium-or long-chain and branched esters. The positional specificities were examined by analyzing the hydrolytic products of triolein catalyzed by the nine lipases, using TLC. The lipases can be mainly classified into two groups by their specificities for the ester bond at position 2 of triglycerides; one group can selectively hydrolyze the ester bond at position 2 of the triglycerides, the other group cannot. All these nine lipases were divided into four groups by hierarchical clustering analysis on the basis of the results of fatty acid and positional specificities.

Lipid metabolism in the rumen: New insights on lipolysis and biohydrogenation with an emphasis on the role of endogenous plant factors

“…Bauchart et al (1990b) found that lipid hydrolysis was much higher in diets enriched with lipids than in diets without lipid supplements. Several authors also noted that LP in the rumen needs a pH of 6-7 (Tamminga and Doreau, 1991), as does the rumen microbial population and their lipolytic activity (Song et al, 2008). When in vivo results from ruminants fed red clover silage, with higher PPO activity, were compared with those fed grass silage with lower PPO activity, it was found that red clover transfers C18:2 and C18:3 from feed to milk more efficiently than grasses Lee et al, 2009a;Moorby et al, 2009).…”

“…These results do not agree with Bauchart et al (1990b), who found that lipolysis was higher in cows fed lipid-supplemented diets than in those fed non supplemented diets. A strong interaction between ruminal pH and both microbial and endogenous lipases has been discovered: indeed the ruminal microbial population has an optimal pH of 6.0-6.7 (Tamminga and Doreau, 1991), while plant endogenous lypolitic systems need an optimum pH of 7-8, (Song et al, 2008). Since PUFA in forage are in the form of glycolipids, more studies on the endogenous lipolytic system appear required, which should focus on how galactolipase activity is influenced by PSM level, rather than PUFA, on microbial activity.…”

Isolation and characterization of an aspartic protease able to hydrolyze and decolorize heme proteins from Aspergillus glaucus

“…Extracts from solid cultures of strain MA0196 showed higher activity toward pNP‐butyrate than pNP‐palmitate (see Supporting information, Table S1). Previously reported lipases from Aspergillus niger and A. oryzae also preferentially act on short‐chain pNP substrates and short‐chain triglycerides . Further investigation of the effects of temperature, pH, moisture content and cultivation period will enable optimized crude enzyme preparations from strain MA0196.…”

Differences in hydrolytic abilities of two crude lipases from Geotrichum candidum 4013

“…Although they have attracted great attention, as can be seen from the many previous works (Loo et al 2007;Song et al 2008), it is still necessary to add more interesting and helpful information on the specificities of lipases, especially those lipases from different microorganisms. Triacylglycerols, fatty acid methyl esters and p-nitrophenyl esters were used as substrates in lipase hydrolysis trials.…”