BACKGROUND : Soda lakes are unique environments in terms of their physical characteristics and the biology they
harbour. Although well studied with respect to their microbial composition, their viral compositions have not, and
consequently few bacteriophages that infect bacteria from haloalkaline environments have been described.
METHODS : Bacteria were isolated from sediment samples of lakes Magadi and Shala. Three phages were isolated on
two different Bacillus species and one Paracoccus species using agar overlays. The growth characteristics of each
phage in its host was investigated and the genome sequences determined and analysed by comparison with
RESULTS : Phage Shbh1 belongs to the family Myoviridae while Mgbh1 and Shpa belong to the Siphoviridae family.
Tetranucleotide usage frequencies and G + C content suggests that Shbh1 and Mgbh1 do not regularly infect, and
have therefore not evolved with, the hosts they were isolated on here. Shbh1 was shown capable of infecting two
different Bacillus species from the two different lakes demonstrating its potential broad-host range. Comparative
analysis of their genome sequence with known phages revealed that, although novel, Shbh1 does share substantial
amino acid similarity with previously described Bacillus infecting phages
(Grass, phiNIT1 and phiAGATE) and belongs to the Bastille group, while Mgbh1 and Shpa are highly novel.
CONCLUSION : The addition of these phages to current databases should help with metagenome/metavirome
annotation efforts. We describe a highly novel Paracoccus infecting virus (Shpa) which together with NgoΦ6 and
vB_PmaS_IMEP1 is one of only three phages known to infect Paracoccus species but does not show similarity to