ISOLATION AND CHARACTERIZATION OF BACTERIAL VIRUSES SPECIFIC TO BACILLUS MEGATERIUM

This study was conducted to isolate and characterize bacteriophages specific to Bacillus megaterium. Seven single lytic phage isolates specific to B. megaterium were successfully isolated from rhizosphere soil of maize plants, growing in the Experimental Farm of Faculty of Agriculture, Minia University, Minia, Egypt. The phages were characterized on the basis of the optimum pH for viral infection, thermal inactivation point, sensitivity to UV radiation, host specificity, as well as particle size, and morphology. The isolated phages exhibited tolerance to alkaline and acidic reactions. All phage isolates were found to be of head and tail types. On the basis of the differences in the studied characteristics of these phages, the seven phage isolates were divided into four groups (A, B, C and D). Phages of each group exhibited the same features (i.e. the optimum pH for infection, thermal inactivation point, sensitivity to UV radiation, host specificity, as well as phage particle size and morphology). Accordingly, the seven phage isolates are belonging to four phage types. These four phage types were designated ÆBm1, ÆBm2, ÆBm3 and ÆBm4.