Modulating lipid metabolism for enhancement of coenzyme Q10 production in Rhodobacter sphaeroides

Coenzyme Q10 (CoQ 10 ), a lipid-soluble isoprenylated benzoquinone essential for electron transfer, is synthesized in the inner mitochondrial membrane of eukaryotes and plasma membrane of prokaryotes like Rhodobacter sphaeroides . Despite its natural production capacity, industrial-scale CoQ 10 synthesis remains limited by ineffective metabolic regulation and scarce genetic tools in R. sphaeroides . This study investigated the relationship between CoQ 10 and intracellular lipid accumulation to enhance production. The engineered strains with higher cardiolipin (CL) levels showed enlarged membrane surfaces, synergistically increasing CoQ 10 production. However, increased triacylglycerol (TAG) accumulation reduced CoQ 10 yields. Disrupting phospholipase D (PLD) and lysophospholipase (PLDB) genes, which reduce phospholipid hydrolysis, further improved CoQ 10 biosynthesis. The optimized strain RS-SQCL04, incorporating all the effective strategies, achieved 824 mg/L CoQ 10 via fed-batch fermentation, a 57.9 % increase over the control. This study provides a promising strategy for industrial CoQ 10 production through phospholipid engineering in R. sphaeroides .