02354naa a2200157 a 450000100080000000500110000800800410001910000150006024500900007526000090016552016470017470000190182170000180184070000170185877303210187513150402008-10-06       2008    bl uuuu     u00u1 u    #d1 aLAPIED, E.  aThe role of soil and digestive tract microbial communities in the earthworm survival.  c2008  aWhilst many studies have investigated the influence of earthworms on soil microflora little work has investigated the role of soil microflora on earthworm survival. Here we tested the survival capacities of axenic and non-axenic earthworms exposed to sterile and non-sterile soils. Axenic earthworms were produced by culture in a microcrystalline cellulose and antibiotics solution. Then, they were inoculated in a sterilized soil re-inoculated or not with a suspension of microorganisms extracted from the original non-sterile soil. Non-axenic earthworms were cultured in the same microcrystalline solution without addition of antibiotics. Then, they were added to non-sterile (control) soil, to sterile autoclaved soil or to the re-inoculated soil. Earthworm survival was measured over 5 weeks. A DGGE analysis was performed on the soils and the surviving depurated earthworms. Within two days after their inoculation in the sterile soil, all the axenic earthworms died. In contrast, all the axenic worms in the re-inoculated soil survived until the end of the experiment. The same results were obtained with non-axenic earthworms. The DGGE showed a similar bacterial community structure between the digestive tract of the axenic and non-axenic earthworms coming from re-inoculated soils. However, the bacterial community structure was different in the nonaxenic earthworms in the non-sterile soil (control). The results of this experiment suggest (i) an absolute necessity of soil microflora for the survival of earthworms, and (ii) that this dependence is not mainly linked to bacterial species but probably to bacterial functional roles.1 aNAHMANI, J. Y.1 aHODSON, M. E.1 aPURDY, K. J.  tIn: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.