one sample and 3 bands for the other sample. These
results indicated a low number of dominant bacteri-
al species in this habitat, which was also found by
other investigators (Moyer et al., 1994, 1995) for a
microbial community from another vent site. Sequenc-
ing of excised DGGE bands revealed sequences sim-
ilar to those of members of the genus Thiomicrospi-
ra, sulfur-oxidizing bacteria, which had been isolated
from similar habitats before. The sequence of another
DGGE band gave the highest similarity value with the
sequence of the sulfate-reducer Desulfovibrio salexi-
gens.