FY 2003

Bacterial diversity in a subseafloor habitat following a deep-sea volcanic eruption

Huber, J.A., D.A. Butterfield, and J.A. Baross

FEMS Microbiol. Ecol., 43(3), doi: 10.1111/j.1574-6941.2003.tb01080.x, 393–409 (2003)

The bacterial diversity in a diffuse flow hydrothermal vent habitat at Axial Volcano, Juan de Fuca Ridge was examined shortly after an eruptive event in 1998 and again in 1999 and 2000 using PCR-amplified 16S rRNA gene sequence analyses. While considerable overlap with deep-sea background seawater was found within the - and -proteobacteria, unique subseafloor phylotypes were distinguishable. These included diverse members of the -proteobacteria, high temperature groups such as Desulfurobacterium, Gram-positive bacteria, and members of novel candidate divisions WS6 and ABY1. Phylotype richness was highest in the particle-attached populations from all three sampling periods, and diversity appeared to increase over that time, particularly among the -proteobacteria. A preliminary model of the subseafloor is presented that relates microbial diversity to temperature, chemical characteristics of diffuse flow fluids and the degree of mixing with seawater.