Diversity of diatom resting stages in surface sediments using V4 fragment of 18S.

Sediments were collected with a gravity corer equipped with three collectors, each 4 cm in diameter, at LTER station MareChiara in the Gulf of Naples (depth 70 m; Tyrrhenian Sea, Mediterranean Sea) on February 7th 2014. The surface sediment (0-1 cm) of each of the three cores were pooled together, gently mixed and placed in a Falcon tube. Before carrying out DNA extraction the samples were stored in the dark at 10°C for 7 weeks in order to ensure that only resting stages survived in the sediments. Two subsamples of 5 g of sediment sample were used to extract DNA. One of them was pre-treated according to Fortin et al. (2004) to remove most of the PCR inhibiting compounds and the extracellular DNA from the sediment. DNA extraction was performed with the PowerMax™ soil DNA isolation kits.