FIG. 6.

DGGE analysis of 16S rDNA fragments obtained after PCR amplification with the bacterial primer pair GM5F-GC-clamp and 907R of genomic DNA from environmental samples and standards with a known melting behavior for June 1996 (A) and September 1996 (B). The environmental samples were obtained at specific locations along a transect from the vent center to the surrounding area. The two cores obtained at 117 cm from the vent center in September were taken 1 week apart. During the first sampling (117 cm I), the white precipitate on the sediment surface was present, whereas during the second sampling (117 cm II), it was absent. No PCR product could be obtained from the overlying water at 165 cm. The numbered bands are described in the text. (A) DGGE pattern of the samples taken in June 1996. Lanes: 1 and 17, standards; 2 to 5, samples taken at 10 cm from the vent center (lane 2, surface, lane 3, 0 to 10 mm; lane 4, 10 to 20 mm; lane 5, 20 to 30 mm); 6 to 9, samples taken at 123 cm (lane 6, surface; lane 7, 0 to 10 mm; lane 8, 10 to 20 mm; lane 9, 20 to 30 mm); 10 to 12, samples taken at 165 cm (lane 10, 0 to 10 mm; lane 11, 10 to 20 mm; lane 12, 20 to 30 mm); 13 to 16, samples taken at 235 cm (lane 13, surface; lane 14, 0 to 10 mm; lane 15, 10 to 20 mm; lane 16, 20 to 30 mm). (B) DGGE pattern of the samples taken in September 1996. Lanes: 1 and 18, standards; 2 to 5, samples taken at 30 cm from the vent center (lane 2, surface; lane 3, 0 to 5 mm; lane 4, 8 to 13 mm; lane 5, 16 to 26 mm); 6 to 9, samples taken at 117 cm (lane 6, surface; lane 7, 0 to 5 mm; lane 8, 8 to 13 mm; lane 9, 16 to 26 mm); 10 to 13, samples taken at 117 cm (lane 10, surface; lane 11, 0 to 5 mm; lane 12, 8 to 13 mm; lane 13, 16 to 26 mm); 14 to 17, samples taken at 200 cm (lane 14, surface; lane 15, 0 to 5 mm; lane 16, 8 to 13 mm; lane 17, 16 to 26 mm).