DNA polymorphisms in new isolates of 'Deinococcus radiopugnans'

Nineteen new Deinococcus isolates from soil, 18 of which were from samples immediately adjacent to a lake in Nottingham, UK, were characterized by conventional criteria, and found to be identical to each other and to conform most closely to the species D. radiopugnans. However, we detected three different restriction enzyme activities in three different isolates. Because of this suggestion of heterogeneity, we examined the isolates for restriction fragment length polymorphisms (RFLPs). RFLP analysis of the 19 original isolates, using three different probes, distinguished 17 divergent groups. This extraordinary diversity cannot be attributed to geographical differences, nor to the method of isolation, which employed UV-radiation selection.