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Immobilization, Regiospecificity Characterization and Application of Aspergillus oryzae Lipase in the Enzymatic Synthesis of the Structured Lipid 1,3-Dioleoyl-2-Palmitoylglycerol.

Cai H, Li Y, Zhao M, Fu G, Lai J, Feng F - PLoS ONE (2015)

Bottom Line: The sn-1,3-specific lipase from Aspergillus oryzae (AOL) is highly and efficiently immobilized with the polystyrene-based hydrophobic resin D3520, with a significant 49.54-fold increase in specific lipase activity compared with the AOL powder in catalyzing the synthesis of OPO through the acidolysis between palm stearin and oleic acid (OA).The following conditions were optimized for the synthesis of structured lipid OPO: 65 °C temperature; 1:8 substrate molar ratio between palm stearin and OA; 8% (w/w) enzyme load; 3.5% water content of the immobilized lipase; and 1 h reaction time.Under these conditions, highly efficient C52 production (45.65%) was achieved, with a tripalmitin content of 2.75% and a sn-2 palmitic acid (PA) proportion of 55.08% in the system.

View Article: PubMed Central - PubMed

Affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China; Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, China.

ABSTRACT
The enzymatic synthesis of 1,3-dioleoyl-2-palmitoylglycerol (OPO), one of the main components of human milk fats, has been hindered by the relatively high cost of sn-1,3-specific lipases and the deficiency in biocatalyst stability. The sn-1,3-specific lipase from Aspergillus oryzae (AOL) is highly and efficiently immobilized with the polystyrene-based hydrophobic resin D3520, with a significant 49.54-fold increase in specific lipase activity compared with the AOL powder in catalyzing the synthesis of OPO through the acidolysis between palm stearin and oleic acid (OA). The optimal immobilization conditions were investigated, including time course, initial protein concentration and solution pH. The sn-1,3 specificity of lipases under different immobilization conditions was evaluated and identified as positively associated with the lipase activity, and the pH of the immobilization solution influenced the regiospecificity and synthetic activity of these lipases. Immobilized AOL D3520, as the biocatalyst, was used for the enzymatic synthesis of the structured lipid OPO through the acidolysis between palm stearin and OA. The following conditions were optimized for the synthesis of structured lipid OPO: 65 °C temperature; 1:8 substrate molar ratio between palm stearin and OA; 8% (w/w) enzyme load; 3.5% water content of the immobilized lipase; and 1 h reaction time. Under these conditions, highly efficient C52 production (45.65%) was achieved, with a tripalmitin content of 2.75% and a sn-2 palmitic acid (PA) proportion of 55.08% in the system.

No MeSH data available.


Effect of adsorption time on fixation level and protein amount in particle (a) and lipase activity and specific activity of AOL D3520 (b).
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pone.0133857.g002: Effect of adsorption time on fixation level and protein amount in particle (a) and lipase activity and specific activity of AOL D3520 (b).

Mentions: The interaction between the lipase and the carrier in lipase immobilization through adsorption is reversible[31], suggesting that the immobilized lipase was sensitive to variations in immobilization conditions. A time course for fixation and acidolysis during AOL D3520 immobilization was conducted. The results, shown in Fig 2A, demonstrated that the fixation level reached 91.29% in only 0.5 h and was slightly increased after 1.0 h. Adsorption at 1.5 h, with a fixation of 98.42%, lipase activity of 147.62 U/g and specific activity 1.00 U/mg, was considered as the time required for the completion of the adsorption of the enzyme into the support, demonstrating through the following plateau of fixation and catalytic efficiency. Although 1 h of adsorption showed slightly higher lipase activity and specific activity, this process was hypothesized as a combination transition state that might influence the stability of the catalyst. Consequently, 1.5 h was used as the immobilization time for further tests.


Immobilization, Regiospecificity Characterization and Application of Aspergillus oryzae Lipase in the Enzymatic Synthesis of the Structured Lipid 1,3-Dioleoyl-2-Palmitoylglycerol.

Cai H, Li Y, Zhao M, Fu G, Lai J, Feng F - PLoS ONE (2015)

Effect of adsorption time on fixation level and protein amount in particle (a) and lipase activity and specific activity of AOL D3520 (b).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4517815&req=5

pone.0133857.g002: Effect of adsorption time on fixation level and protein amount in particle (a) and lipase activity and specific activity of AOL D3520 (b).
Mentions: The interaction between the lipase and the carrier in lipase immobilization through adsorption is reversible[31], suggesting that the immobilized lipase was sensitive to variations in immobilization conditions. A time course for fixation and acidolysis during AOL D3520 immobilization was conducted. The results, shown in Fig 2A, demonstrated that the fixation level reached 91.29% in only 0.5 h and was slightly increased after 1.0 h. Adsorption at 1.5 h, with a fixation of 98.42%, lipase activity of 147.62 U/g and specific activity 1.00 U/mg, was considered as the time required for the completion of the adsorption of the enzyme into the support, demonstrating through the following plateau of fixation and catalytic efficiency. Although 1 h of adsorption showed slightly higher lipase activity and specific activity, this process was hypothesized as a combination transition state that might influence the stability of the catalyst. Consequently, 1.5 h was used as the immobilization time for further tests.

Bottom Line: The sn-1,3-specific lipase from Aspergillus oryzae (AOL) is highly and efficiently immobilized with the polystyrene-based hydrophobic resin D3520, with a significant 49.54-fold increase in specific lipase activity compared with the AOL powder in catalyzing the synthesis of OPO through the acidolysis between palm stearin and oleic acid (OA).The following conditions were optimized for the synthesis of structured lipid OPO: 65 °C temperature; 1:8 substrate molar ratio between palm stearin and OA; 8% (w/w) enzyme load; 3.5% water content of the immobilized lipase; and 1 h reaction time.Under these conditions, highly efficient C52 production (45.65%) was achieved, with a tripalmitin content of 2.75% and a sn-2 palmitic acid (PA) proportion of 55.08% in the system.

View Article: PubMed Central - PubMed

Affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China; Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, China.

ABSTRACT
The enzymatic synthesis of 1,3-dioleoyl-2-palmitoylglycerol (OPO), one of the main components of human milk fats, has been hindered by the relatively high cost of sn-1,3-specific lipases and the deficiency in biocatalyst stability. The sn-1,3-specific lipase from Aspergillus oryzae (AOL) is highly and efficiently immobilized with the polystyrene-based hydrophobic resin D3520, with a significant 49.54-fold increase in specific lipase activity compared with the AOL powder in catalyzing the synthesis of OPO through the acidolysis between palm stearin and oleic acid (OA). The optimal immobilization conditions were investigated, including time course, initial protein concentration and solution pH. The sn-1,3 specificity of lipases under different immobilization conditions was evaluated and identified as positively associated with the lipase activity, and the pH of the immobilization solution influenced the regiospecificity and synthetic activity of these lipases. Immobilized AOL D3520, as the biocatalyst, was used for the enzymatic synthesis of the structured lipid OPO through the acidolysis between palm stearin and OA. The following conditions were optimized for the synthesis of structured lipid OPO: 65 °C temperature; 1:8 substrate molar ratio between palm stearin and OA; 8% (w/w) enzyme load; 3.5% water content of the immobilized lipase; and 1 h reaction time. Under these conditions, highly efficient C52 production (45.65%) was achieved, with a tripalmitin content of 2.75% and a sn-2 palmitic acid (PA) proportion of 55.08% in the system.

No MeSH data available.