Prokaryotic cell abundance and biomass measured during Maria S. Merian cruise MSM29 and Polarstern cruise PS85 to the Fram Strait

Prokaryotic cell abundances and biomass were determined in deep-sea sediment samples collected at the deep-sea LTER HAUSGARTEN, located in the Fram Strait. Sampling was performed during two cruises, i.e. RV Maria S. Merian MSM 29 in summer 2013 (23 June-12 July) and RV Polarstern PS85 in summer 2014 (6 June-3 July). Undisturbed sediment cores were collected with a TV-guided multicorer. Prokaryotic cell abundances were determined using acridine orange direct counts, following the procedure described in (Hoffmann et al., 2017; doi:10.3389/fmicb.2017.00266). For each sample two replicate filters were counted. Cell volumes were determined using a stage micrometer and converted to biomass using a conversion factor of 3 x 10^-13 g C /µm³ (Børsheim, K. Y., Bratbak, G., and Heldal, M. (1990). Enumeration and biomass estimation of planktonic bacteria and viruses by transmission electron microscopy. Applied and Environmental Microbiology 56, 352-356).