Engineering the β-Oxidation Pathway in for the Production of -10, -12-Conjugated Linoleic Acid.

-10, -12-Conjugated linoleic acid (10, 12-CLA) is an octadecadienoic acid with various biological benefits. Previously, linoleic acid isomerase from (PAI) was overexpressed in () to produce 10, 12-CLA. However, the 10, 12-CLA yield was restricted by the peroxisomal β-oxidation pathway. In this study, to minimize the degradation of 10, 12-CLA, four genetically modified strains of ( and ) were constructed and compared in terms of production stability and yield of 10, 12-CLA using safflower seed oil as substrates. The strain exhibited the best results, as revealed by the reduction of the 10, 12-CLA degradation rate from 58.5 to 18.6 mg/L/h. Additionally, the YLUpex10mP recombinant strain bearing six copies of o combined with deletion enhanced 10, 12-CLA production to 7.4 g/L and exhibited a CLA degradation rate of 19.7 mg/L/h, a 78% decrease from that of the control strain. Finally, in a bioreactor containing low-cost volatile fatty acids as partial carbon sources, the 10, 12-CLA content in the YLUpex10mP strain increased to 9.7 g/L, 1.3 times higher than in flasks. To our knowledge, this is the highest 10, 12-CLA yield through microbial synthesis reported to date.