Tenea Gabriela N, Reyes Pamela, Flores Carlos
Biofood and Nutraceutics Research and Development Group, Faculty of Engineering in Agricultural and Environmental Sciences, Universidad Técnica del Norte, Ibarra, Ecuador.
Front Microbiol. 2025 Mar 19;16:1570312. doi: 10.3389/fmicb.2025.1570312. eCollection 2025.
Strawberries are renowned for their exceptional flavor and nutritional properties but have a short shelf life due to rapid ripening and a high vulnerability to postharvest microbial decay. Postbiotic formulations (PBFs) derived from lactic acid bacteria (LAB) can be developed into effective preservation products, extending postharvest shelf life while maintaining fruit quality.
This study aimed to assess the effects of postbiotic-based formulations (PBFs) consisting of two key components: (1) a precipitated peptide-protein extract (PP) from UTNGt21O, serving as the antimicrobial agent, and (2) an exopolysaccharide (EPS) from UTNCys2-2, functioning as the biopolymer carrier. These formulations were tested against a multidrug-resistant P4StpC1 strain, isolated from ready-to-eat strawberries, and their potential mode of action was analyzed . Time-kill assays and electron microscopy were used to evaluate their impact on the target cells. Furthermore, the performance of PBFs was compared to a commercial disinfectant (C1) in terms of their effects on strawberry microbiota and fruit quality, employing bacteriological techniques and 16S amplicon metagenomic analysis.
The selected PBFs showed bacteriolytic effect on . The target cell viability was significantly reduced upon 1 h co-cultivation by inducing several morphological and ultrastructural modifications. Dipping strawberries at the ripe stage four in PBFs indicated no increase in total cell counts, thus the microorganisms colonization was retained during storage with refrigeration. The 16S metagenome analysis showed that the treatment impacted the fruit microbiota, significantly increasing abundance ( < 0.001) by day eight compared to the disinfectant control. This suggests the formulation supports beneficial microbes, enhancing antimicrobial effects. Additionally, the postbiotic coating improved shelf-life, preserved fruit quality, and delayed deterioration in strawberries. The strawberries quality attributes were not affected by the treatment. Principal Component Analysis (PCA) revealed clear sample separation based on maturity stage, independent of the treatment.
The results highlight the potential of crosslinking of a peptide-protein fraction with EPS to prevent the colonization of undesirable microorganisms on postharvest strawberries while enhancing their safety and quality.
草莓以其独特的风味和营养特性而闻名，但由于成熟迅速且采后极易受到微生物腐烂的影响，其货架期较短。源自乳酸菌（LAB）的后生元制剂（PBFs）可开发成有效的保鲜产品，延长采后货架期并保持果实品质。
本研究旨在评估由两个关键成分组成的基于后生元的制剂（PBFs）的效果：（1）来自UTNGt21O的沉淀肽 - 蛋白质提取物（PP），作为抗菌剂，以及（2）来自UTNCys2 - 2的胞外多糖（EPS），作为生物聚合物载体。这些制剂针对从即食草莓中分离出的多重耐药P4StpC1菌株进行了测试，并分析了它们潜在的作用模式。采用时间 - 杀菌试验和电子显微镜来评估它们对靶细胞的影响。此外，就其对草莓微生物群和果实品质的影响而言，将PBFs的性能与一种商业消毒剂（C1）进行了比较，采用了细菌学技术和16S扩增子宏基因组分析。
所选的PBFs对……显示出溶菌作用。通过诱导几种形态和超微结构修饰，共培养1小时后靶细胞活力显著降低。在成熟阶段四将草莓浸泡在PBFs中表明总细胞数没有增加，因此在冷藏储存期间微生物定植得以保留。16S宏基因组分析表明，与消毒剂对照相比，到第8天处理对果实微生物群有影响，显著增加了……丰度（<0.001）。这表明该制剂支持有益微生物，增强了抗菌效果。此外，后生元涂层改善了货架期，保持了果实品质，并延缓了草莓的变质。草莓的品质属性不受处理影响。主成分分析（PCA）显示基于成熟阶段有明显的样本分离，与处理无关。
结果突出了肽 - 蛋白质部分与EPS交联的潜力，以防止采后草莓上不良微生物的定植，同时提高其安全性和品质。
