The large application potential of microbiotas has led to a great need for mixed culture methods. However, microbial interactions can compromise the maintenance of biodiversity during cultivation in a reactor. In particular, competition among species can lead to a strong disequilibrium in favor of the fittest microorganism. In this study, an invert emulsion system was designed by dispersing culture medium in a mixture of sunflower oil and the surfactant PGPR. Granulomorphometric analysis was performed to investigate the effect of incubation and of the introduction of bacteria on the particle size distribution of invert emulsions. Selected bacteria were propagated as single-strain cultures in order to assess the effect of invert emulsion on bacterial growth upon 24 h and 72 h timescales. A two-strain antagonistic model was co-cultivated on a range of inoculum levels in order to inquire into the bacterial interaction alleviation properties of invert emulsions. Finally, the effect of this cultivation system on the structure of bacterial communities was assessed by propagating a bacterial consortium consisting of six bacterial species. Metabarcoding analysis was then conducted by Illumina sequencing of 16S rRNA (v4) gene amplimers.