We are testing a number of biocontrol bacteria (eg. Burkholderia, Pseudomonas and Stenotrophomonas) for toxicity to bacterial feeding nematodes including C. elegans N2 and
pgp-3. Serratia marcescens in particular had a measurable effect on number of eggs over 24 hours and relative motility in microtiter wells. Serratia marcescens strains with increasing amounts of red pigmentation (BF1-5@ (albino), D1, N4-5, NIMA) were tested for relative motility to C. elegans N2,
pgp3, Oscheius myriophila DF5020, Panagrellus redivivus PS 1163, Mesorhabditis sp. PS1170 and Zeldia punctata PS 1153. Toxicity directly increases with decreasing amount of pigment in Caenorhabditis, Oscheius and Panagrellus. The order of relative toxicity is reversed for the 2 highly pigmented strains and the 2 least pigmented strains (2143 vs. 1234) in Mesorhabditis and Zeldia. These nematodes are phylogenetically distant from C. elegans. Bacterial strains were provided by Phyllis Martin and Dan Roberts, USDA.