Effective Expression of the Serratia marcescens Phospholipase A1 Gene in Escherichia coli BL21(DE3), Enzyme Characterization, and Crude Rapeseed Oil Degumming via a Free Enzyme Approach.
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ABSTRACT: Crude oil degumming by phospholipid removal is crucial to guarantee oil quality. Phospholipase degumming could produce green vegetable oil by reducing energy consumption and protecting the environment. To develop a novel phospholipase for oil degumming, we cloned the Serratia marcescens outer membrane phospholipase A gene (OM-PLA1) and expressed its 33 KDa protein in engineered Escherichia coli BL21(DE3). OM-PLA1 activity reached 18.9 U mL-1 with the induction of 0.6 mM isopropyl ?-D-1-thiogalactopyranoside for 4 h. The optimum temperature and pH were 50°C and 7.5, respectively. Mg2+, Ca2+, Co2+, and Mn2+ at 0.1 mM L-1 significantly increased OM-PLA1 activity. The kinetic equations of OM-PLA1 and Lecitase Ultra were y = 13.7x+0.74 (Km = 18.53 mM, Vmax = 1.35 mM min-1) and y = 24.42x+0.58 (Km = 42.1 mM, Vmax = 1.72 mM min-1), respectively. The phosphorus content decreased from 22.6 to 9.3 mg kg-1 with the addition of 15 units of free recombinant OM-PLA1 into 150 g of crude rapeseed oil. OM-PLA1 has the close degumming efficiency with Lecitase Ultra. The S. marcescens outer membrane phospholipase gene (OM-PLA1) possessed higher substrate affinity and catalytic efficiency than Lecitase Ultra. This study provides an alternative approach to achieve crude vegetable oil degumming with enzymatic technology.
SUBMITTER: Yang P
PROVIDER: S-EPMC6811509 | biostudies-literature | 2019
REPOSITORIES: biostudies-literature
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