TECNALIA, Basque Research and Technology Alliance (BRTA), Health and Food Area, Health Division, Parque Tecnológico de Álava, Leonardo Da Vinci 11, 01510, Miñano, Spain.
Lactiker Research Group, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de La Universidad 7, 01006, Vitoria-Gasteiz, Spain.
Sci Rep. 2022 Nov 7;12(1):18904. doi: 10.1038/s41598-022-22875-w.
Probiotic metabolites, known as postbiotics, have received attention due to their wide variety of promoting health effects. One of the most exciting postbiotic is gamma-aminobutyric acid (GABA), widely produced by lactic acid bacteria, due to its benefits in health. In addition, the performance of the biosynthesis of GABA by Lactiplantibacillus plantarum could be modulated through the modification of fermentation parameters. Due to their high nutritional value, agri-food by-products could be considered a useful fermentation source for microorganisms. Therefore, these by-products were proposed as fermentation substrates to produce GABA in this study. Previously, several experiments in Man Rogosa Sharpe (MRS) broth were performed to identify the most critical parameters to produce GABA using the strain Lactiplantibacillus plantarum K16. The percentage of inoculum, the initial pH, and the concentration of nutrients, such as monosodium glutamate or glucose, significantly affected the biosynthetic pathway of GABA. The highest GABA yield was obtained with 500 mM of monosodium glutamate and 25 g/L of glucose, and an initial pH of 5.5 and 1.2% inoculum. Furthermore, these investigated parameters were used to evaluate the possibility of using tomato, green pepper, apple, or orange by-products to get GABA-enriched fermented media, which is an excellent way to revalorise them.
益生菌代谢产物，被称为后生元，因其具有广泛的促进健康的作用而受到关注。其中最令人兴奋的后生元之一是γ-氨基丁酸（GABA），它广泛存在于乳酸菌中，具有多种健康益处。此外，通过改变发酵参数，可以调节植物乳杆菌合成 GABA 的生物合成性能。由于其高营养价值，农业食品副产物可以被认为是微生物发酵的有用来源。因此，本研究提出了这些副产物作为发酵底物来生产 GABA。此前，在 Man Rogosa Sharpe（MRS）肉汤中进行了多项实验，以使用植物乳杆菌 K16 确定产生 GABA 的最关键参数。接种量、初始 pH 值以及谷氨酸单盐或葡萄糖等营养物质的浓度显著影响 GABA 的生物合成途径。在 500mM 谷氨酸单盐和 25g/L 葡萄糖、初始 pH 值为 5.5 和 1.2%接种量的条件下，获得了最高的 GABA 产量。此外，还利用这些研究参数评估了利用番茄、青椒、苹果或橙副产物获得富含 GABA 的发酵培养基的可能性，这是一种极好的再利用方法。
