The response of Paracoccus sp. SKG to acetonitrile-induced oxidative stress.

Organic solvents enhance intracellular oxidative stress and induce various physiological responses in bacteria. The study shows the morphological changes in Paracoccus sp. SKG when exposed to higher concentrations of acetonitrile, which alter the composition of the membrane fatty acid that accompanies the increase in K(+) efflux. This enhances the oxidative stress with greater activities of catalase and super oxide dismutase (SOD). The increased oxidative stress results in the generation of free radicals, which was confirmed by electron paramagnetic resonance (EPR) studies. The free radical scavenging activities were measured by ABTS and DPPH to understand the non-enzymatic defensive system during oxidative stress. The studies demonstrate the increase in free radicals in association with enzymatic and non-enzymatic defense systems under solvent stress.