Influence of some chemicals and solvents on the lytic activity and the adsorption of bacteriophages on Pectobacterium carotovoroum subsp. carotovorum

Abstract

Recently, bacteriophages have been used to control hazardous bacterial soft rot disease on crops. However, agricultural plants are frequently treated with different chemicals (fertilizers, pesticides and solvents), so we assessed the effect of some commonly used chemicals and solvents on the lytic activity of tested bacteriophages and their adsorption potential. This study reports the isolation of three specific phages against the Pectobacterium carotovorum subsp. carotovorum DSM 30170 strain, designated as ϕPC1, ϕPC2 and ϕPC3, then partially characterized using electron microscopy and genome size. The 3 isolated phages belong to the Myoviridae family. The results obtained were based on the plaque-forming unit observed after incubation. By increasing the chemical concentrations (from 0.1 to 0.5 mM), calcium chloride (CaCl2) and potassium chloride (KCl) showed a significant increase in the lytic activity of the phages. Copper sulphate (CuSO4) and copper chloride (CuCl2) showed a substantial decrease in the activity of ϕPC3; however, such a decrease was insignificant for ϕPC1 and ϕPC2. By increasing the solvent concentrations (from 30 % v/v to 70 % v/v), propanol, ethanol and methanol showed a significant decrease in the count of the three isolated phages, ϕPC1, ϕPC2 and ϕPC3, compared to the control. Chloroform was the only solvent that did not reduce the phage titer. Our findings offer significant information for developing a strategy to combat the P. carotovorum subsp. carotovorum caused bacterial soft rot disease. avoiding copper compounds and alcoholic solvents such as propanol, ethanol and methanol in plots where phages are applied seems advisable.