Improvement of Agrobacterium tumefaciens strains for enhancing CoQ10 producibility

Abstract

Coenzyme Q10 (CoQ10) plays a role in electron transport and is one of the important components of the respiratory chain. In present CoQ10 is used more as a source of functional food or treatment supporting dmg due to strong antioxidant properties and its beneficial role in the treatment of many serious diseases as cancer, cardiovascular, diabetes,... Many biological processes have been developed to produce CoQ10 on a large scale. These processes are mainly relied on microorganisms because they have the ability to generate high levels of CoQ10. Among the CoQlO producing microorganisms, Agrobacterium tumefaciens is considered as species with CoQ10 producibiliiy in lai'ge scale due to their ability to produce large amounts of CoQ10 on the simple, inexpensive media. The purpose of this research is to increase the activity of tvi'o key enzymes of CoQ10 synthesis (decaprenyl diphosphate synthase and 1 - deoxy - D - xylulose 5 - phosphate synthase), leading to improve the CoQ10 producibility OĨA. lumefaciens. Two genes dps and dxs from A. tumefaciens TT4 strain encoding decaprenyl diphosphate synthase and I - deoxy - D - xylulose 5 - phosphate synthase respectively were successfully cloned in the cloning vector pJETl.2. These two genes were further inserted into the expression vector pCAMBlA130l I, in turn transferred into the host strain A. tumefaciens ERA 105. The CoQ10 producing ability of recombinants was determined 1.8 rimes higher than the original one. Of the 28 clones of A. fume/aciens carrying recombinant structure pCAM-dps-dxs, 3 clones with capable of the highest CoQ10 biosynthesis were selected for subsequent studies.