Complete genome sequences of StopSmel and Aussie, two Mu-like bacteriophages of Sinorhizobium meliloti

Abstract

We report the complete genome sequences of two bacteriophages, Aussie and StopSmel, isolated from soil using the host Sinorhizobium meliloti NRRL L-50. The genomes are similar in length and gene content and share 76% nucleotide identity. Comparative analysis of Aussie and StopSmel identified core functional modules associated with Mu-like bacteriophages.

Keywords: Mu-like bacteriophage; Sinorhizobium meliloti; agriculture.

Fig 1

Plaque morphology for phages (A) Aussie and (B) StopSmel infecting Sinorhizobium meliloti NRRL L-50 after incubation on tryptone yeast agar plates at 28°C for 48 h. (C) Electron micrograph of StopSmel prepared by applying 10 µL of phage solution to the top of 200 mesh formvar-coated copper grids (Ted Pella, Redding, CA, USA) for 1 minute. Phage solutions were wicked and grids were then stained with a 1% uranyl acetate solution for 1 minute. TEM was performed to visualize the phage morphology using an accelerating voltage of 25 kV. StopSmel has siphovirus morphology with a non-contractile tail of 123 nm and capsid of 54 nm (scale bar = 200 nm). Samples viewed with a Hitachi 4800 STEM electron microscope (USDA, ARS, U.S. Horticultural Research Lab, Fort Pierce, FL, USA).