Farkas Zuzana, Romeo Rosa, Pangallo Domenico, Kraková Lucia, Giuffrè Angelo M, Sidari Rossana
Institute of Molecular Biology, Slovak Academy of Science, Dúbravská cesta 21, Bratislava, 84551, Slovakia.
Department of Agraria, Mediterranea University of Reggio Calabria, Reggio Calabria, 89122, Italy.
World J Microbiol Biotechnol. 2025 Jul 28;41(8):283. doi: 10.1007/s11274-025-04495-4.
Oleuropein is the most abundant bioactive phenolic compound olive trees (Olea europaea L.). It is found in all parts of the plant, but especially in the leaves. This study describes the bioconversion of oleuropein to hydroxytyrosol, a polyphenol with antioxidant and antibacterial properties, by the fermentation of olive leaves by lactic acid bacteria (LAB), using a new, more eco-friendly method that is not based on chemical solvent extraction. This method uses an aqueous solution with reduced glucose content to which ground leaves are added and subsequently inoculated with LAB strains. In this experiment, the pH, glucose, and LAB strains are key factors. We tested a total of fourteen LAB strains for β-glucosidase activity, from which we selected the five with the best demonstrated activity - Lactiplantibacillus plantarum PB22, Fructilactobacillus sanfranciscensis B415, Lactiplantibacillus pentosus B506, Lactiplantibacillus pentosus B307 and Lactiplantibacillus plantarum B329. The bioconversion was monitored over 28 days using a UPLC system coupled with a UV/Vis Photo Diode Array. The best strains for converting oleuropein to hydroxytyrosol were F. sanfranciscensis B415, L. pentosus B506, and L. pentosus B307 and the optimum fermentation time was found to be 3 days. This work proposes an environmentally friendly low-impact method for reusing agricultural plant wastes.
橄榄苦苷是橄榄树（油橄榄）中含量最丰富的生物活性酚类化合物。它存在于植物的各个部位，但在叶子中含量尤其丰富。本研究描述了通过乳酸菌（LAB）发酵橄榄叶，将橄榄苦苷生物转化为具有抗氧化和抗菌特性的多酚羟基酪醇的过程，采用了一种新的、更环保的方法，该方法不基于化学溶剂萃取。此方法使用葡萄糖含量降低的水溶液，向其中加入磨碎的叶子，随后接种LAB菌株。在本实验中，pH值、葡萄糖和LAB菌株是关键因素。我们总共测试了14种LAB菌株的β-葡萄糖苷酶活性，从中选出了活性表现最佳的5种——植物乳杆菌PB22、旧金山乳杆菌B415、戊糖片球菌B506、戊糖片球菌B307和植物乳杆菌B329。使用超高效液相色谱系统结合紫外/可见光电二极管阵列对生物转化过程进行了28天的监测。将橄榄苦苷转化为羟基酪醇的最佳菌株是旧金山乳杆菌B415、戊糖片球菌B506和戊糖片球菌B307，最佳发酵时间为3天。这项工作提出了一种环境友好、低影响的方法来再利用农业植物废弃物。
