Marine microbes have an important role on biogeochemical cycles, since they manage the recycling and remineralization of many essential nutrients. Due to climate change and global warming, an increase in frequency of heat waves has been observed in the Mediterranean Sea area, which could have an important impact on the resilience and structure of the marine microbial communities. Here, we have addressed the effect of these heat waves on the marine microbes during 20 days in situ mesocosm that was conducted as part of the EuropeanAquacosm-plus-TA project at the CNRS-MEDIMER infrastructure (Sète, France). A scenario of an occurrence of two consecutive heat-waves up to 5°C above natural temperature was tested. Triplicate 1700L mesocosms were heated each 5 days followed by 5 days without heating. Triplicate other mesocosms acted as controls without heating.To assess diversity and abundance changes in bacterial communities, the 16S rRNA analysis, microscopy and flow cytometry analyses were carried out. To analyze the functional changes in microbial communities, metagenomic analyses were performed as well as metabolic activity assays using BONCAT tagging. This method allows tracking metabolically active cells after the incorporation of a non-canonical aminoacid followed by fluorescent labelling of these proteins by CLICK chemistry. In this work, we will show the results from these multi-omic analyses and we will try to highlight the effect of global warming on the microbial communities in the Mediterranean Sea; one of the most sensitive oceanic “biosensor” within global warming.

Primary Presenter: Maria Alvarez-Sanchez, Universidad de Alicante (maria.alvarez@ua.es)

Authors:

Maria Alvarez-Sanchez, Instituto Multidisciplinar Para el Estudio del Medio ‘‘Ramón Margalef’’; Universidad de Alicante, Alicante, Spain; Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain.  (maria.alvarez@ua.es)

Laura Carmona-Valenzuela, Universidad de Alicante  (lcv22@alu.ua.es)

Lucia Maestre-Carballa, Instituto Multidisciplinar Para el Estudio del Medio ‘‘Ramón Margalef’’; Universidad de Alicante, Alicante, Spain; Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain  (l.maestre@ua.es)

Aitana Llorenç-Vicedo, Instituto Multidisciplinar Para el Estudio del Medio ‘‘Ramón Margalef’’; Universidad de Alicante, Alicante, Spain; Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain  (aitana.llorens@ua.es)

Behzad Mostajir, MARBEC (MARine Biodiversity, Exploitation and Conservation), Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France  (behzad.mostajir@umontpellier.fr)

Francesca Vidussi, MARBEC (MARine Biodiversity, Exploitation and Conservation), Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France  (francesca.vidussi@cnrs.fr)

Victoria Orphan, Department of Geological and Planetary Sciences, California Institute of Technology, California, Unite Statates  (vorphan@gps.caltech.edu)

Manuel Martínez-García, Instituto Multidisciplinar Para el Estudio del Medio ‘‘Ramón Margalef’’; Universidad de Alicante, Alicante, Spain; Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain  (m.martinez@ua.es)