T10,c12-conjugated linoleic acid engineering bacterial strain, recombinant expression plasmid thereof, construction method and application thereof

The invention provides a t10,c12-conjugated linoleic acid engineering bacterial strain, a recombinant expression plasmid thereof, a construction method and an application thereof. By means of high-efficient expression of linoleic acid isomerase gene sourced from propionibacterium acnes in an oil-producing mildew mortierella ramanniana, a genetic transformation system of the mortierella ramanniana which is mediated by agrobacterium tumefaciens with hygromycin as a selection marker is established and optimized for the first time, and further a mortierella ramanniana engineering strain for synthesizing the single-activity isomer t10,c12-CLA through catalysis on endogenous linoleic acid through linoleic acid isomerase is constructed, wherein the t10,c12-CLA is synthesized successfully through fermentation by the strain. The method is used for producing the single CLA isomer through a one-step method with the endogenous linoleic acid. In the invention, the linoleate isomerase (PAI) is expressed in the mortierella ramanniana to produce the t10,c12-conjugated linoleic acid with the linoleic acid in mycelia of the mildew as a catalytic substrate.