Rapid microbial production of filamentous sulfur mats at hydrothermal vents

During recent oceanographic cruises to Pacific hydrothermal vent sites (9 degrees N and the Guaymas Basin), the rapid microbial formation of filamentous sulfur mats by a new chemoautotrophic, hydrogen sulfide-oxidizing bacterium was documented in both in situ and shipboard experiments. Observations suggest that formation of these sulfur mats may be a factor in the initial colonization of hydrothermal surfaces by macrofaunal Alvinella worms. This novel metabolic capability, previously shown to be carried out by a coastal strain in H2S continuous-flow reactors, may be an important, heretofore unconsidered, source of microbial organic matter production at deep-sea hydrothermal vents.

Comparison of a new thiomicrospira strain from the mid-atlantic ridge with known hydrothermal vent isolates

A new autotrophic Thiomicrospira strain, MA-3, was isolated from the surface of a polymetal sulfide deposit collected at a Mid-Atlantic Ridge hydrothermal vent site. The DNA homology among three vent isolates, Thiomicrospira crunogena, Thiomicrospira sp. strain L-12, and Thiomicrospira sp. strain MA-3, was 99.3% or higher, grouping them as the same species, T. crunogena (type strain, ATCC 35932). The fact that T. crunogena and Thiomicrospira sp. strain L-12 were isolated from Pacific vent sites demonstrates a cosmopolitan distribution of this species.