Bacteriocins are potent antimicrobial polypeptides and proteins produced by most lineages of Bacteria and, perhaps, by all members of Archaea (O'Connor & Shand, 2002; Riley & Wertz, 2002a, 2002b; Tagg et al., 1976). Although initially the focus of numerous
biochemical, evolutionary, and ecological studies, more recently, their potential to serve in
human and animal health applications has taken center stage (Gillor et al., 2008). The use of
bacteriocins in probiotic applications, as preservatives, and, (most excitingly) as alternatives
to classical antibiotics is being broadly explored (Abee et al., 1995; Einarsson & Lauzon,
1995; Gillor & Ghazaryan, 2007; Gillor et al., 2007).
Most bacterial species produce one or more bacteriocins (Cascales et al., 2007). One of the
most prolific bacteriocin-producing species is Pseudomonas aeruginosa, of which 90% or more
of the strains tested produce their own version of bacteriocins, known as pyocins (Govan &
Harris, 1985). In contrast, only 15-50% of Escherichia coli produce their brand of bacteriocins,
known as colicins (Riley & Gordon, 1992). The colicins are exceedingly well characterized
proteins, and have been the subject of numerous detailed biochemical, molecular,
evolutionary, and ecological analyses (Cascales et al., 2007; Riley et al., 2003; Riley &
Gordon, 1999; Riley & Wertz, 2002a, 2002b). Some species of bacteria produce toxins that
may exhibit numerous bacteriocin-like features, but have not yet been fully characterized;
these toxins are referred to as bacteriocin-like inhibitory substances, or BLIS (Messi et al.,
2003; Moro et al., 1997).
In this chapter, we will explore the bacteriocins of aquatic bacteria, particularly those of
potential interest in the seafood industry. A short primer of bacteriocin biology is followed
by a detailed review of the diversity of bacteriocins described from marine microorganisms.
These toxins have received far less attention than bacteriocins produced by terrestrial or
human-commensal bacteria, yet they have equivalent potential as antibiotics and even
greater promise for use in the creation of probiotic strains for the seafood industry.