Characteristics of Bacteriophages specific to salt tolerant Azotobacter sp. in Minia Soils.

Five isolates of Azotobacter were isolated from different locations in Minia Governorate - Egypt anddesignated Az1, Az2 Az3, Az4 and Az5. Az3 was found to be most tolerant isolate to NaCl. Bacterialviruses of Azotobacter (Az3) were isolated from soil samples collected from Minia Governorate. Twelvesingle plaques of Azotobacter phages, were isolated. Due to the similarity of the phage isolates in theiroptimum pH sensitivity to UV (260 nm), thermal inactivation point and host range the phages ofAzotobacter were classified into groups A and B. On the basis of electron microscope study, Azotobacterphages of every group were found to be similar in their size and morphology. Generally, the obtainedresults indicated that, the twelve isolates of Azotobacter phage belong to two types of phage. These twophage types were named Az 1, Az 2.