Image caption The bacteria were grown from 19-year-old samples taken from the Titanic

A never-before-seen microbe has been found in the wreck of RMS Titanic.

The Halomonas titanicae bacterium was found in "rusticles", the porous and delicate icicle-like structures that form on rusting iron.

Various bacteria and fungi live within the delicate structures - first identified on the Titanic - actually feeding off the rusting metal.

The find is described in the journal International Journal of Systematic and Evolutionary Microbiology.

Samples of rusticles from Titanic were gathered in 1991 by the Mir 2 robotic submersible.

Image caption The rusticles are delicate, poorly-understood homes for many bacteria

Researchers from Dalhousie University and the Ontario Science Centre in Canada and the University of Seville in Spain isolated the H. titanicae bacteria from those samples.

They sequenced the microbes' DNA before discovering that they constituted a new member of the salt-loving Halomonas genus.

The bacteria are of particular interest because they may shed light on the mechanism by which rusticles form, and thus on the general "recycling" that such microbes carry out on submerged metal structures.

That, the authors point out, has relevance also to the protection of offshore oil and gas pipelines, and the safe disposal at sea of ships and oil rigs.