Thesis title: Analysis of the diversity of endophytic and rhizospheric bacteria in order to isolate bacteria that can stimulate the growth of Synsepalum dulcificum (Schumach & Thonn.) Daniell.

Synsepalum dulcificum (Schumach & Thonn.) Daniell is a shrub native to West Africa that is famous for its red berries known to be, to date, the only natural source of "miraculin", a glycoprotein with sweetening properties contained in the fruit pulp. In West Africa, this plant species has more than 70 documented local food, medicinal, pharmaceutical and economic applications, making it a strategic bio-economic resource whose significant production would accelerate the socio-economic development of producing and exporting countries. However, its cultivation is still underdeveloped and is subject to several production constraints including: slow growth, prolonged juvenile period and pest attacks. Thus, in a context of agro-ecological protection of plant productions, the use of bacteria of interest called PGPR (Plant Growth Promoting Rhizobacteria) and PGPE (Plant Growth Promoting Endophyte), promoting on the one hand, the absorption of nutrients by plants and on the other hand, the growth of inoculated plants, appears as an innovative and sustainable lever.  It is within this framework that this thesis study aims to i) study the diversity of rhizospheric and endophytic bacterial communities of a panel of S. dulcificum accessions, ii) isolate bacteria of interest in order to create a consortium that can stimulate the growth of the species, iii) evaluate the effect of the mixed bacterial inoculum created on the juvenile growth of S. dulcificum and iv) identify the genes expressed by plants after the inoculation by RNAseq approaches.

This study will provide farmers with sustainable strategies for intensifying production of this crop and improving its nutritional quality to meet the needs of national and international markets.