Isolation and Identification of Bacillus megaterium Bacteriophages via AFLP Technique

Abstract

Ten bacteriophages specific for Bacillus megaterium were isolated from a clay loam soil sample collected from the Experimental Farm of Faculty of Agriculture, Minia University, Minia, Egypt. Four out of ten isolates were inactivated after exposure to 80°C for 10 min and three isolates were inactivated at 78°C for 10 min. Whereas, the other three phage isolates were inactivated at 82°C for 10 min. The isolated phages were found to be tolerant to wide range of pH 5-9. The longevity in vitro varied between the phage isolates. The highest longevity in vitro was recorded for four phage isolates (192 h). Electron micrographs of the isolated phages indicated that all phage isolates were of the head and tail types. Two different host specificities were observed for the ten phage isolates (two different populations). Six phage isolates (population 1) were found to be infectious to B. megaterium among the four species tested (i.e., B. megaterium, B. circulans, B. polymexa and B. subtilis). Whereas, the rest of the phage isolates (population 2) were found to be infectious to B. megaterium and B. subtilis. The dendrogram separated the 10 phage isolates into two main clusters (two populations) and then each cluster was separated into two sub clusters. Isolates that belonged to the same host range were grouped together. The percentage of variation was 9% among populations and 91% within populations. The five most remarkable isolates were submitted to the bacillus database and named BMC1, BMC2, BMC3, BMC4 and BMC5.