ARS | Publication request: (R)-3-hydroxyacyl-ACP:CoA transacylase of Pseudomonas chlororaphis: gene cloning, characterization and knock-out on PHA and rhamnolipid syntheses

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: October 26, 2011
Publication Date: N/A

Technical Abstract: Pseudomonas chlororaphis is a useful microorganism capable of producing polyhydroxyalkanoate (PHA) biopolymer and rhamnolipid (RL) biosurfactants by using carbon- and nitrogen-sources derived from renewable feedstocks as substrates of fermentation. We are interested in increasing the yield of RL production to economize the process. The biosynthesis of PHA and RL both require 3-hydroxyacyl molecule as a precursor. (R)-3-hydroxyacyl-ACP:CoA transacylase (PhaG) is the enzyme responsible for diverting the flow of 3-hydroxyacyl precursor to the PHA biosynthesis pathway. We hypothesize that by inactivating the PhaG activity, the precursor flow could be directed to favor RL production. In this presentation, we describe the cloning and characterization of the P. chlororaphis phaG gene, and the subsequent construction of phaG-negative knock-out P. chlororaphis mutants. These mutants are important for testing the effects of phaG inactivation on PHA and RL biosynthesis, which could lead to increased and economic production of RL biosurfactant.