Résumé
A culturomic approach involves the use of a range of different culture conditions coupled with a high-throughput method of identification to be able to isolate and identify microorganisms in a sample. A number of studies have shown that using plant-based culture media rather than conventional media that contain chemically synthesized or animal-based extracts can successfully increase the cultivability of plant-associated microbiota. This study aimed to use a culturomic approach to build a collection of grapevine foliar microorganisms, which can subsequently be used to build Synthetic microbial Communities (SynComs) for biocontrol of downy mildew (caused by Plasmopara viticola). For the collection, leaves were sampled from parcels that showed high and low susceptibility to downy mildew. Alongside four conventional culture media, we developed a grapevine leaf based culture medium to cultivate epiphytic and endophytic bacteria, yeast and filamentous fungi. We proceeded to identify the isolates by MALDI-TOF MS and Sanger sequencing. Overall, we isolated 1091 microorganisms including 544 bacteria, 217 yeast and 330 filamentous fungi. We were able to identify 86% of the isolates with 93 total genera identified across the five culture media used. Using the grapevine leaf based culture medium enabled the cultivation of 4 genera of bacteria, 1 yeast genus and 13 genera of filamentous that were not seen on the other media.