Bacterial Diversity at a Shallow-Water Hydrothermal Vent (Espalamaca) in Azores Island

A low-temperature shallow-water hydrothermal vent field was discovered during the summer of 2010 in the Faial-Pico channel off the Espalamaca headland, Faial Island, Azores, Portugal, NE Atlantic. The present study analyses bacterial communities present in shallow-water hydrothermal vent of Espalamaca using SSU rRNA-based clone library approach. Clones of shallow vent sediment sample revealed the dominance of Proteobacteria (including alpha, gamma, epsilon, delta, zeta subdivisions) and Bacteroidetes with 36% and 28% of the whole community respectively. The dominance of gamma-Proteobacteria is the unique characteristic of this shallow vent and it coincides with the South Tonga Arc and Bahia Concepcion (Pacific Ocean), whereas epsilon-Proteobacteria groups were reported to be high in the majority of the hydrothermal vents. Though the sampling sites of the venting and non-venting regions of Espalamaca were only 500 m apart, high variation (>80%) of phylotypes was found between the regions.