Nanomechanical properties of the sea-water bacterium Paracoccus seriniphilus—A scanning force microscopy approach

Abstract

The measurement of force-distance curves on a single bacterium provides a unique opportunity to detect properties such as the turgor pressure under various environmental conditions. Marine bacteria are very interesting candidates for the production of pharmaceuticals, but are only little studied so far. Therefore, the elastic behavior of Paracoccus seriniphilus, an enzyme producing marine organism, is presented in this study. After a careful evaluation of the optimal measurement conditions, the spring constant and the turgor pressure are determined as a function of ionic strength and pH. Whereas the ionic strength changes the turgor pressure passively, the results give a hint that the change to acidic pH increases the turgor pressure by an active mechanism. Furthermore, it could be shown, that P. seriniphilus has adhesive protrusions outside its cell wall.

FluidFM as a tool to study adhesion forces of bacteria - Optimization of parameters and comparison to conventional bacterial probe Scanning Force Spectroscopy

“…Both bacteria have a size of 0,5–1 μm. The spherical, gram negative seawater bacterium Paracoccus seriniphilus was grown in complex medium as described elsewhere [ 26 ]. For both strains, precultures were incubated for 17 hours at 30° C. Afterwards, the precultures were diluted and kept at 30° C for another 24 hours before they were diluted in 0.9% NaCl solution for subsequent SCFS measurements.…”

“…Both bacteria have a size of 0,5-1 μm. The spherical, gram negative seawater bacterium Paracoccus seriniphilus was grown in complex medium as described elsewhere [26]. For both strains, precultures were incubated for 17 hours at 30˚C.…”

“…For our setup, this was 5 μm/s. In addition, we investigated the effect of viscoelasticity when the z-speed is increased as described in [26]. For all the investigated values of the z-speed the elasticity stays unchanged within the error bars.…”

FluidFM as a Tool to Study Adhesion Forces of Bacteria - Optimization of Parameters and Comparison to Conventional Bacterial Probe Scanning Force Spectroscopy

“…lactis was grown in DSMZ medium 11 (Leibniz Institute DSMZ -German Collection of Microorganisms and Cell Cultures). The spherical, gramnegative seawater bacterium Paracoccus seriniphilus was grown in complex medium as described elsewhere [21]. For both strains, precultures were incubated for 17 hours at 30° C. Afterwards, the precultures were diluted and kept at 30° C for another 24 hours before they were diluted in 0.9 % NaCl solution for subsequent SCFS measurements.…”