This study explores the ability of lactic acid bacteria (LAB) to ferment soy juice. The ability of 276 LAB strains from 25 species to ferment the principal soy carbohydrates, sucrose, raffinose or stachyose was tested in synthetic media and a soy juice. Fermented soy juices (FSJs) were characterized for their odor. Selected FSJs were characterized by targeted metabolomics. All Streptococcus, 83% of Leuconostoc and Lactobacillus and 41% of Lactococcus strains were sucrose-positive, while only 36% of all the LAB strains tested were raffinose-positive and 6% stachyose-positive. Nearly all (97%) the sucrose-positive strains fermented soy juice, indicating that an ability to use sucrose is a good criterion to select strains for soy juice fermentation. Among the most efficient acidifying strains, 46 FSJs had an odor deemed to be acceptable. FSJ composition was dependent on both species and strains: 17/46 strains deglycosylated soy juice isoflavones, the 27 S. thermophilus strains converted a mean 4.4 ± 0.1 g/L of sucrose into 3.0 ± 0.1 g/L of lactic acid versus 5.2 ± 0.1 g/L into 2.2 ± 0.1 g/L for the 18 Lactobacillus and one Lactococcus strains. This study highlights the diversity of the metabolic profiles of LAB strains in soy juice fermentation.

本研究探讨了乳酸菌 (LAB) 发酵豆汁的能力。在合成培养基和豆汁中测试了来自 25 个物种的 276 种 LAB 菌株发酵主要大豆碳水化合物、蔗糖、棉子糖或水苏糖的能力。发酵豆汁（FSJ）的特征在于其气味。选定的 FSJ 通过靶向代谢组学进行表征。所有链球菌、83% 的明串珠菌和乳杆菌以及 41% 的乳球菌菌株均为蔗糖阳性，而所有测试的 LAB 菌株中只有 36% 为棉子糖阳性，6% 为水苏糖阳性。几乎所有（97%）蔗糖阳性菌株都发酵豆汁，这表明使用蔗糖的能力是选择用于豆汁发酵的菌株的良好标准。在最有效的酸化菌株中，46 个 FSJ 的气味被认为是可以接受的。 FSJ 组成取决于物种和菌株：17/46 株将大豆汁异黄酮去糖基化，27株嗜热链球菌菌株将平均 4.4 ± 0.1 g/L 的蔗糖转化为 3.0 ± 0.1 g/L 的乳酸，而 5.2 ± 0.1 g/L 的乳酸则为5.2 ± 0.1 g/L。对于 18 种乳杆菌和一种乳球菌菌株，将 g/L 调整为 2.2 ± 0.1 g/L。这项研究强调了豆汁发酵中 LAB 菌株代谢特征的多样性。