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Identification des interactions positives entre bactéries lactiques en fermentation de jus de soja

Abstract : Lactofermented soy juices represent an interesting alternative to milk yogurt to increase the part of plant-based proteins in our diet. The choice of lactic acid bacteria (LAB) used for soy juice fermentation is crucial as it determines the organoleptic and nutritional properties of the product. LAB metabolisms are however not well known in soy juice fermentation. In this thesis, 276 strains of 25 species were screened in synthetic media on their ability to ferment stachyose, raffinose and sucrose as unique source of carbon and soy juice. We showed that i) LAB capacity to catabolize sucrose is important to ferment soy juice ii) S. thermophilus strains are the most efficient to ferment soy juice iii) Lactobacillus LAB produce diverse aromatic notes according to the specie and the strain. LAB association can help to improve fermentation, the organoleptic and the nutritional properties. We associated then LAB in duo according to their metabolic complementarities. One coculture out of 32 improved the organoleptic properties of fermented soy juices compared to the monocultures. One coculture out of 12 reduced of 30% the SJ fermentation time (L. plantarum CIRM-BIA777 (Lp777) and L. delbrueckii CIRM-BIA865 (Ld865)). Genomic, metabolomics and transcriptomics approaches were set up to identify the molecular bases of these two LAB cooperation. These approaches revealed three factors of stress of LAB in soy juice fermentation: the limitation of sucrose, the limitation of free amino acids and the oxidative stress. The level of these three stresses were lowered with Lp777 and Ld865 coculture in soy juice. Limiting these stresses is then of interest in order to improve soy juice fermentations.
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https://hal.inrae.fr/tel-03135726
Contributor : Anne Giboulot <>
Submitted on : Tuesday, February 9, 2021 - 11:13:16 AM
Last modification on : Wednesday, February 17, 2021 - 3:32:44 AM
Long-term archiving on: : Monday, May 10, 2021 - 6:29:19 PM

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  • HAL Id : tel-03135726, version 1

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Olivier Harle. Identification des interactions positives entre bactéries lactiques en fermentation de jus de soja. Alimentation et Nutrition. Institut Agro, Rennes, 2020. Français. ⟨tel-03135726⟩

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