Work

Loss of PA0619 Enhances Crude Rhamnolipid Extract Yield and Attenuates Virulence in P. aeruginosa

Year: 2026

Type: article

Abstract: Rhamnolipids are versatile biosurfactants with immense industrial potential, yet their scalable production in P. aeruginosa is constrained by limited yields. To identify novel regulators, we constructed a rhlAB-luxCDABE reporter strain to screen a genome-wide transposon insertion library containing 30,000 mutant colonies and identified 53 candidate genes whose disruption resulted in more than two-fold changes in the normalized rhlAB reporter activity. Among the four selected candidates with 15-fold variation in rhlAB reporter activity, PA0619 disruption consistently enhanced PrhlAB promoter activity and shifted P. aeruginosa toward a stronger extracellular biosurfactant-associated output. Furthermore, ΔPA0619 also increased crude rhamnolipid extract yield and elevated rhlAB promoter activity. In parallel, ΔPA0619 showed reduced pyocyanin production, biofilm formation, and tissue damage in a Chinese cabbage infection model. These findings identify PA0619 as a genetic locus connecting rhlAB expression, extracellular biosurfactant-associated phenotypes, and selected virulence-related traits in P. aeruginosa.

Source: Microorganisms

DOI: 10.3390/microorganisms14112564