Nematology (1999) 1, 687-693

R.C. Han and R.U. Ehlers (1999)
Trans-specific nematicidal activity of Photorhabdus luminescens
Nematology 1 (7-8), 687-693
Abstract: Mixed culture filtrates of Photorhabdus luminescens isolated from Heterorhabditis bacteriophora H06 and from H. indica LN2 had a toxic effect on axenic H. bacteriophora H06 dauer juveniles. Single culture filtrates had no effect. When one filtrate originated from a secondary phase culture, the toxic effect was lost. Heat treatment of one of the filtrates to 80°C destroyed the effect. The toxin is probably synthesized de novo after mixing the culture supernatants of these two P. luminescens symbionts. Dilution of the filtrate reduced the effect, and it was lost when P. luminescens was cultured for more than two days. Steinernema carpocapsae A24 was not affected by the mixture, and was affected only by the filtrate of primary phase P. luminescens H06. The toxic effect was recorded also when axenic dauer juveniles of H. bacteriophora were inoculated into a mixed bacterial culture of H06 and LN2. Inoculating monoxenic dauer juveniles of H. bacteriophora H06 into P. luminescens LN2 or into mixtures containing LN2 bacteria resulted in significant dauer juvenile mortality. These manifestations of the interaction of bacteria to produce toxic effects on the non-symbiotic nematode (trans-specific activity) may have an impact on competitive interactions when one insect host is infected by different nematode species.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ralf-Udo Ehlers

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Steinernema carpocapsae/Xenorhabdus nematophila (entomopathogen)
Heterorhabditis bacteriophora/Photorhabdus (entomopathogen)