Metal recognition by in-vitro selection

The influence of external factors on bacteriophages--review

The ability of bacteriophages to survive under unfavorable conditions is highly diversified. We summarize the influence of different external physical and chemical factors, such as temperature, acidity, and ions, on phage persistence. The relationships between a phage’s morphology and its survival abilities suggested by some authors are also discussed. A better understanding of the complex problem of phage sensitivity to external factors may be useful not only for those interested in pharmaceutical and agricultural applications of bacteriophages, but also for others working with phages.

Metal-ion discrimination by phage T7

The discovery of new metal-selective complexing agents may be facilitated by applying an in vitro selection strategy. Such a strategy was recently devised to identify and enrich populations of bacteriophage that rely on Mg(II)-, Zn(II)-, or Au(III)-selective stabilization for survival in the presence of denaturing urea. The potential for extension of the strategy to other metal ions is investigated here. The kinetics of phage inactivation in 5 M urea was measured for a spectrum of metals. At a concentration of 1 mM, Mg(II), Ca(II), Co(II), and Ni(II) were found to be the most stabilizing, followed by Cd(II), Cu(II), and Zn(II), respectively. K(I) had virtually no effect. In contrast, Al(III) and Au(III) significantly destabilized the phage, even at concentrations of 0.25 mM.