초록
<P>The multifunctional lipoxygenase PhLOX cloned from <I>Pyropia haitanensis</I> was expressed in <I>Escherichia coli</I> with 24.4 mg·L<SUP>–1</SUP> yield. PhLOX could catalyze the one-step bioconversion of C18–C22 fatty acids into C8–C9 volatile organic compounds (VOCs), displaying higher catalytic efficiency for eicosenoic and docosenoic acids than for octadecenoic acids. C20:5 was the most suitable substrate among the tested fatty acids. The C8–C9 VOCs were generated in good yields from fatty acids, e.g., 2<I>E</I>-nonenal from C20:4, and 2<I>E</I>,6<I>Z</I>-nonadienal from C20:5. Hydrolyzed oils were also tested as substrates. The reactions mainly generated 2<I>E</I>,4<I>E</I>-pentadienal, 2<I>E</I>-octenal, and 2<I>E</I>,4<I>E</I>-octadienal from hydrolyzed sunflower seed oil, corn oil, and fish oil, respectively. PhLOX showed good stability after storage at 4 °C for 2 weeks and broad tolerance to pH and temperature. These desirable properties of PhLOX make it a promising novel biocatalyst for the industrial production of volatile aroma compounds.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2018/jafcau.2018.66.issue-5/acs.jafc.7b05341/production/images/medium/jf-2017-053418_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf7b05341'>ACS Electronic Supporting Info</A></P>