Diversity of magnetotactic bacteria from a French pristine Mediterranean area.

Magnetotactic bacteria synthesize intracellular magnetite and/or greigite magnetosome crystals. They play a significant role in both iron and sulfur cycles in sedimentary aquatic environments. To get insight into the bio-geochemical contribution of MTB, more studies concerning their ecology and their distribution in diverse habitats are necessary. The MTB community of an oil-industry polluted area of the French Mediterranean coast has been previously investigated. Here, we investigate the MTB community from coastal sediments of a Mediterranean pristine area using optical and transmission electron microscopy and phylogenetic analysis based on 16S rRNA gene sequences. A particularly high diversity of MTB was observed, with cocci phylogenetically distributed across the order Magnetococcales, including a novel cluster with sequences from the Mediterranean Sea designated as "Med group", and novel morphotypes.