1. Initial results from the screening of PROSOPE and Roscoff cultures Florence LE GALL, Héloïse FELMAN, Frédéric PARTENSKY, Nathalie SIMON, Dominique MARIE, Daniel VAULOT

2. The first steps of isolation Surface water of ASTAN 2 filtrations on 3µm Enumeration by flow cytometry Culture in liquid medium K/10, K/100, K/10+Si,F/20 Serial dilutions K/10 Culture on plate K medium (0,6%agar)

3. Isolation and purification of microalgae Flow cytometry sorting Serial dilutions 160 precultures (PROSOPE) 38 strains isolated 24 eukaryotes 14 Synechococcus

4. Synechococcus spectra wavelength PROSOPE 157-13 PUB PEB wavelength PROSOPE 53-4 PEB PUB

5. HPLC analysis and presence of caracteristic pigments PROSOPE culture 3 PROSOPE culture 18 MgDVPPrasViolaNeo Diadchr Chl b Chl a Neo Viola Lut Chl b Chl a ß-car MgDVP : Mg-2,4-divinyl pheoporphyrin a5 Pras : Prasinoxanthin Diadchr : Diadinochrome Neo : Neoxanthin Viola : Violaxanthin Chl b : Chlorophyll b Chl a : Chlorophyll a Lut : Lutein ß-car : ß-carotene Prasinophyceae Chlorophyceae

6. PROSOPE culture 96 ASTAN culture R 000412-4 Chl c2 Chl c3 19HF Fuco Diadino Chl a Chl c3 Chl c2 Fuco Diadino Diato Chl a ß-car 19HF :19-Hexanoyloxyfucoxanthin Fuco : Fucoxanthin Diadino : Diadinoxanthin Chl c2 : Chlorophyll c2 Chl c3 : Chlorophyll c3 Chl a : Chlorophyll a Diato : Diatoxanthin ß-car : ß-carotene Prymnesiophyceae Bacillariophyceae

7. Morphological characterization Optical microscopy Transmission electronic microscopy

8. 0.11.010.0 Scatter 0.1 1 10 100 1000 Chl fluorescence Ostreo. ocea Bolid.med Bolid.pacifi Ostreo. taur Micro pusi Iso. Galb. E. huxleyi Phaeocystis PRO_3 PRO_22 PRO_5 Peuk Astan PRO_36 PRO_63 Euk Astan (K) PRO_114-2 PRO_18-1 PRO_96 PRO_118-1 PRO_90 Euk Astan (F/2) PRO_140-3 PRO_1 PRO_64 PRO_32 PRO_54 Prymnesiophyceae Bolidophyceae Prasinophyceae Chlorophyceae Prymnesiophyceae Cultures from - Med Sea (PRO) - Roscoff Diatom

9. Summary Prymnesiophyceae : 11 strains Prasinophyceae : 3 strains Chlorophyceae : 1 strain Bacillariophyceae : 1 strain