Worm Breeder's Gazette 3(2): 32
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
For eight months we cultivate on the A1 medium the Bristol strain primitively grown with E. coli on NG agar medium. The A1 medium is currently used for the Bergerac strain and its composition ( Brun 1966 ) is : [See Figure 1] At 18 C, in this medium, N2 shows a good adaptation. After 60 generations its life cycle duration was less than 3 1/2 days and the adult produced 298 +/- 11 progeny whose 78%, were produced in the 2 first days of laying. This is consistent with results obtained with NG agar medium ( Brenner 1974 ), but very different of those observed with the Bergerac strain on the A1 medium : 137 + 9 progeny per nematode with only 62% in the 2 first days of laying, and a 4 days generation time. Therefore the differences in productivity and development between Bergerac and Bristol strains do not come from the chemical composition of the media. They could result either from intrinsic differences between the 2 strains, or from differences in interaction with bacteria because the N2 cultivation is monoxenic and the Bergerac one is xenic. Since last october, N2 is cultured on A1 medium,in aseptic conditions, without seeding E. coli into the plates. The only transferred bacteria were those carried by worms themselves. After five months of cultivation, the bacterial species associated with N2 were identified. We do not find E. coli, but Enterobacter agglomerans, an Enterobacteriaceae as E. coli, but rather different of it. The identification tests were carried out on 70 characters.