ABSTRACT

The classical approach of comparing biochemical and cultural characteristics is the one used most widely for studying the taxonomy of Xenorhabdus. The increasing interest in Xenorhabdus reflects growing awareness that the bacterial partner plays a significant role in nematode/ bacterium associations beyond mass production of the nematode vector. Clarification of the taxonomy of Xenorhabdus serves two utilitarian purposes: providing labels to report data obtained with different Xenorhabdus isolates so that meaningful comparisons can be made, and providing the basis for a system of identification that may be required for government registration purposes. The usefulness of electrophoresis in the taxonomy of Xenorhabdus has yet to be tested by extensive examination of intraspecific variation. The variety of antimicrobial agents produced by each species of Xenorhabdus suggests that antimicrobial activity is very important for the nematode/bacterium associations. Taxonomic studies confirm that each species of entomopathogenic nematode has a specific natural association with only one Xenorhabdus species.