Incubation Experiments of DOM with Prokaryotic Community at the NW Mediterranean Sea site MOLA in 2021

The water samples for the incubation experiment were collected on the RV Néréïs II at the Microbial Observatory Laboratory Arago 42N and 4E on 31 May and 26 August 2021. The parameters include DOC/TDN/DON/TDP/DOP, dissolved hydrolyzable amino acids, fluorescent dissolved organic matter (FDOM), enzyme activity, prokaryote heterotrophic production (PHP), prokaryote and viral abundance. The incubation temperature was temperature +13ºC for both experiments. DOC/TDN was analyzed using High-Temperature Catalytic Oxidation (TOC-VCSH). DIN/TDP/DOP was analyzed using a Technicon Auto Analyzer. Dissolved hydrolyzable amino acids were analyzed using High Performal Liquid Chromatography (HPLC). FDOM was measured on a FP-8500 Spectrofluorimeter (Jasco, Japan). Enzymatic activities were measured using 4-methylumbelliferyl-butyrate (esterase), 4-methylumbelliferyl phosphate for alkaline phosphatase (APase), and L-leucine-7-amido-4-methyl coumarin for leu-aminopeptidase (AMA). PHP was measured using 3h-leucine and the microcentrifuge method. Prokaryote and viral abundance were measured on a flow cytometer (Cytoflex, Beckman Coulter, USA). The purpose of data collection was to understand the seasonal cycling of organic matter and heterotrophic bacteria dynamics within the microbial loop.