Effect of toluene onPseudomonas stutzeriST-9 morphology — plasmolysis, cell size, and formation of outer membrane vesicles

Abstract

Isolated toluene-degrading Pseudomonas stutzeri ST-9 bacteria were grown in a minimal medium containing toluene (100 mg·L(-1)) (MMT) or glucose (MMG) as the sole carbon source, with specific growth rates of 0.019 h(-1) and 0.042 h(-1), respectively. Scanning (SEM) as well as transmission (TEM) electron microscope analyses showed that the bacterial cells grown to mid-log phase in the presence of toluene possess a plasmolysis space. TEM analysis revealed that bacterial cells that were grown in MMT were surrounded by an additional "material" with small vesicles in between. Membrane integrity was analyzed by leakage of 260 nm absorbing material and demonstrated only 7% and 8% leakage from cultures grown in MMT compared with MMG. X-ray microanalysis showed a 4.3-fold increase in Mg and a 3-fold increase in P in cells grown in MMT compared with cells grown in MMG. Fluorescence-activated cell sorting (FACS) analysis indicated that the permeability of the membrane to propidium iodide was 12.6% and 19.6% when the cultures were grown in MMG and MMT, respectively. The bacterial cell length increased by 8.5% ± 0.1% and 17% ± 2%, as measured using SEM images and FACS analysis, respectively. The results obtained in this research show that the presence of toluene led to morphology changes, such as plasmolysis, cell size, and formation of outer membrane vesicles. However, it does not cause significant damage to membrane integrity.

Quartz Crystal Microbalance with Dissipation Monitoring of Dynamic Viscoelastic Changes of Tobacco BY-2 Cells under Different Osmotic Conditions

“…A comparison of the transcriptional changes induced by water stress resulted in the identification of genes whose expression was specifically affected in most species [ 44 , 45 ]. Some special chemicals should change the membrane permeability, in order to change the concentration of ions that induced initial plasmolysis [ 46 ]. So osmotic stress can affect the plant cell to adapt to its environment, through affecting the composition the cell wall.…”

Proteomic Assessment of the Expression of Genes Related to Toluene Catabolism and Porin Synthesis in Pseudomonas stutzeri ST-9

“…Transmission as well as scanning electron analyses indicated that strain ST-9 of P. stutzeri, which was grown in the presence of toluene possesses a plasmolysis space and is surrounded by an additional "material" with small vesicles in between. 18 We assume that the morphological changes of P. stutzeri ST-9 are correlated to its response to the presence of toluene.…”