Isolation and complete genome sequence of a bacteriophage lysing Tetrasphaera jenkinsii, a filamentous bacteria responsible for bulking in activated sludge

The Nosticoida limicola filamentous morphotype is held responsible for incidents of bulking and foaming in activated sludge. Members of the actinobacterial N. limicola II have been isolated and grown in pure culture and shown to belong to the genus Tetrasphaera, and play an important role in phosphorus removal. This article describes the isolation and genomic characterization of a phage able to lyse Tetrasphaera jenkinsii, TJE1. This lytic phage is a member of the Caudovirales specific for T. jenkinsii. The complete DNA sequence of TJE1 phage revealed it to have a circularly permuted genome (49,219 bp) with 66 putative open reading frames, a single transcriptional terminator, and 6 pairs of inverted repeats within the genome sequence. The TJE1 phage genome is organised into a modular gene structure, but shares only limited sequence identity with other phages so far described.