Dimethyl phthalate destroys the cell membrane structural integrity of Pseudomonas fluorescens

Abstract

A Gram-negative bacteria (Pseudomonas fluorescens) was exposed to different concentrations (0, 20, and 40 mg/L) of dimethyl phthalate (DMP) for 8 h, and then Fourier transform infrared spectroscopy (FTIR) analysis, lipopolysaccharide content detection, analysis of fatty acids, calcein release test, proteomics, non-targeted metabolomics, and enzyme activity assays were used to evaluate the toxicological effect of DMP on P. fluorescens. The results showed that DMP exposure caused an increase in the unsaturated fatty acid/saturated fatty acid (UFA/SFA) ratio and in the release of lipopolysaccharides (LPSs) from the cell outer membrane (OM) of P. fluorescens. Moreover, DMP regulated the abundances of phosphatidyl ethanolamine (PE) and phosphatidyl glycerol (PG) of P. fluorescens and induced dye leakage from an artificial membrane. Additionally, excessive reactive oxygen species (ROS), malondialdehyde (MDA), and changes in antioxidant enzymes (i.e., catalase [CAT] and superoxide dismutase [SOD]) activities, as well as the inhibition of Ca2+-Mg2+-ATPase and Na+/K+-ATPase activities in P. fluorescens, which were induced by the DMP. In summary, DMP could disrupt the lipid asymmetry of the outer membrane, increase the fluidity of the cell membrane, and destroy the integrity of the cell membrane of P. fluorescens through lipid peroxidation, oxidative stress, and ion imbalance.

Is aromatic plants environmental health engineering (APEHE) a leverage point of the earth system?

“…DMP is known to affect the activity of several bacteria [ [143] , [144] , [145] , [146] ], and many plants, such as Osmanthus fragrans, Black tea, Crabapple (Malus sp.) fruit, and the same composition has been found in volatiles [ [147] , [148] , [149] , [150] ].…”

Engineering the synthesis of unsaturated fatty acids by introducing desaturase improved the stress tolerance of yeast

“…33 Regulation of fatty acid content helps cells adapt to varying stress conditions by maintaining membrane fluidity, lipid bilayer permeability and protein activity. 34,35 The recombinant S. cerevisiae cells exhibited enhanced multiple stress resistance due to the improvement of membrane fluidity and integrity (Figs 4 and 5). The fluidity and integrity of cell membranes are closely related to the maintenance of cell membrane homeostasis to improve the stress tolerance of yeast.…”

“…Maintaining cell membrane structure and functionality is essential for cell metabolism under stressful environments 33 . Regulation of fatty acid content helps cells adapt to varying stress conditions by maintaining membrane fluidity, lipid bilayer permeability and protein activity 34,35 . The recombinant S. cerevisiae cells exhibited enhanced multiple stress resistance due to the improvement of membrane fluidity and integrity (Figs 4 and 5).…”