[en] This thesis addressed issues related to rice wine production development in Cambodia. The choice of alcoholic ferment starter is one of the most influencing factors on the yield and quality of the alcoholic beverage. The microbial composition of starters varied according to the regions where they were produced and was influenced by the environment and the material used. Through this study, a first rRNA pyro-sequencing to study the microbiota of traditional Cambodian starters was developed. The results of Chapter 3.1 highlighted the impact of the composition of the microbiota on the profile of the synthesized aromatic compounds. The dominant strains, mainly the filamentous fungus Rhizopus oryzae, the yeast Saccharomyces cerevisiae and the lactic acid bacteria Lactobacillus plantarum have been identified. These three strains have been reported to significantly affect the aromatics profile of the wine. The results of Chapter 3.2 detailed the important role of these three strains in the process of replacing the natural community. The aromatic profile was complementary to that of the natural community (Dombea); moreover, some unpleasant aromas have been reduced when using the controlled and known synthetic community. Another part of the study highlighted the importance of choosing the type of device used for biofilm cultivation to favour its attachment. Chapter 3.3 focused on the evaluation of the fermentation system on the attachment of Trichoderma spp. and the production of hydrophobins. In this respect, two fermentation systems (SFE, DFR) were evaluated. All the results showed the importance of the choice of the device for the biofilm culture, especially in the case of the study of microbial interactions. Thus, the alternative bioreactor design makes it possible to understand and better control the interaction as well as the structuration of the synthetic community studied. Biofilm reactors have made it possible to better control the complex morphology of the mycelium. The results of this study could be considered as a promising avenue for the development of rice wine fermentation technology in Cambodia.
