Effect of corona plasma on Agrobacterium tumefaciens

Yulia Lazra, The Department of Chemical Engineering and Biotechnology, Ariel University, Ariel, Israel
Dr. Rivka Cahan, The Department Of Chemical Engineering And Biotechnology, Ariel University, Ariel, Israel

Around a third of agricultural crops is lost as a result of nematodes, viruses and pathogenic fungi and bacteria found in the soil. The problem increases when the agricultural crops grow continuously without brake between the seasons. Chemical treatment is the main method of soil disinfection. The chemicals contaminate the soil, impair its fertility, and cause decreases in water and air quality.

Plasmas are considered as an ionized gas which can be divided into two types according to their gas temperature, "Hot" plasmas (near-equilibrium plasmas) and "Cold" plasmas (non-equilibrium plasmas). Hot plasmas are characterized by very high temperatures of electrons and heavy particles, whereas cold plasmas are composed of low temperature particles and relatively high temperature electrons. Cold plasmas include low-pressure direct current (DC), radio frequency (RF) discharges (silent discharges) and discharges appearing in fluorescent (neon) illuminating tubes and corona plasma discharges (atmospheric pressure). Cold plasma was reported as an efficient technology for bacterial eradication.

Agrobacterium tumefaciens is a soil rod shaped, motile, Gram-negative bacteria. Grows aerobically, without forming endospores, having one to six peritrichous flagella. The cells width is 0.6-1.0 µm and length is 1.5-3.0 µm, and may exist as a single or in pair. A. tumefaciens cause plant diseases such as crown gall and hairy root.
In this study, the disinfection efficiency of corona plasma was examined on Agrobacterium tumefaciens, in order to find an environmentally friendly eradication method.