Based on the form and the size of the cells, the number of
magnetosomes chains, and the crystal type, at least 10
morphotypes were observed by transmission electron
microscopy (Fig. 1). As expected from the light microscope
observations, the majority of MTB from Six-Foursles-
Plages were cocci ([95 % of the MTB population). The
majority was 1.4 9 1.2 (±0.2) lm in size (Fig. 1a); others
were 2.1 (±0.2) lm in diameter (Fig. 1b); and a third group
was 2.7 9 2.4 (± 0.2) lm in size (Fig. 1c, d). Moreover,
we observed at least 2 rods (Fig. 1e, f); two vibrios
(Fig. 1g, h); and two spirilla morphotypes (Fig. 1i, j).