Impact of nanoscale zero valent iron on bacteria is growth phase dependent

Role of oxidative stress in inactivation of Escherichia coli BW25113 by nanoscale zero-valent iron

“…2c). This might due to the adaptation of bacterial cells toward stationary phase since cells in stationary phase exhibited higher resistance to nZVI (Chaithawiwat et al, 2016). This was further confirmed by the inactivation of cells from stationary phase, in which all the mutants except rpoS showed less than 2 log inactivation after exposed to nZVI for 1 h (Fig.…”

“…nZVI was characterized for size, zeta potential, and elemental composition. The characterization methods and results are available in Chaithawiwat et al (2016).…”

“…Six mutants including JW3879-1 (ΔsodA), JW1648-1 (ΔsodB), JW1638-1 (ΔsodC), JW3914-1(ΔkatG), JW1721-1 (ΔkatE), and JW5437-1 (ΔrpoS) were obtained from the Coli Genetic Stock Center at Yale University and used in this study. E. coli is a common model strain used in previous studies on impact of nZVI on bacteria (Auffan et al, 2008;Chaithawiwat et al, 2016;Lee et al, 2008). The BW 25113 strain was chosen because the availability of targeted mutants.…”

“…Despite the wide applications of nZVI, several studies suggested that the particles can post adverse effects on living cells, including both prokaryotic and eukaryotic cells (Auffan et al, 2008;Chaithawiwat et al, 2016;Diao and Yao, 2009;Keenan et al, 2009;Lee et al, 2008;Saccà et al, 2013). Exposure of high concentrations of nZVI to human bronchial epithelial cells can rapidly inactivate these cells (Keenan et al, 2009).…”

“…In a study conducted by Chaithawiwat et al (2016), the responses of bacterial cells in different growth phases to nZVI were determined, and higher resistance in stationary phase cells was observed. Many oxidative stress related gene expressions are highly dependent on the growth phase.…”