A lysogenic bacterium is one which contains in its
genome the
DNA of a
virus which is lying
dormant, passively letting itself be
replicated by the bacterium whenever the bacterium replicates its own genome (a
lysogenic virus). However, the virus is able to reactivate and destroy the bacterium at any time (it becomes a
lytic virus).
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.