Photorhabdus luminescens ssp. laumondii strain TT01 was
the first completely sequenced member of this group of
entomopathogenic bacteria and nematode symbionts bacteria
[3]. Within the genome sequence several insecticidal
proteins, hydrolytic enzymes (proteases, lipases, and
chitinases) have been identified which are involved in the
complex life cycle between the bacterium, its nematode
host Heterorhabditis, as well as the insect prey. Moreover,
several gene-encoding enzymes involved in secondary
metabolite biosynthesis have been identified and a careful
reanalysis of the genome sequence led to the identification
of at least 23 biosynthesis gene clusters that
correspond to more than 6.5% of the overall genome
sequence (HB Bode, unpublished data). These numbers
would put Photorhabdus very close to the Gram-positive
bacteria of the genus Streptomyces that are usually
regarded as potent secondary metabolite producers. Most
of the identified biosynthesis gene clusters encode NRPS
[26] that are involved in the biosynthesis of linear or
cyclized peptides, lipopeptides or depsipeptides, and two
encode hybrids of PKS [27,28] and NRPS. Moreover, one
biosynthesis gene cluster encoding an unusual fatty acid
synthase (FAS) or a FAS/PKS hybrid, a type II PKS, as
well as two biosynthesis gene clusters involved in siderophore
biosynthesis have been identified.