Abstract

Autochthonous dairy lactic acid bacteria (LAB) isolates encompass a natural source of starter, adjunct, or probiotic candidates. In this context, traditionally manufactured, using exclusively animal rennet, Feta-type cheeses were collected from five farms located in different regions of Kefalonia island (Greece). The primary objective of this study was to isolate and characterize novel LAB, thereby exploring the unmapped microbial communities of Kefalonian Feta-type cheese and identifying new potential probiotics. The initial screening, included a preliminary gastrointestinal (GI) tolerance assessment (acidic conditions and bile salts), followed by their safety evaluation (hemolytic activity and antibiotic susceptibility). Based on the preliminary screening, selected strains underwent molecular identification and were further investigated for their probiotic attributes (lysozyme and phenol resistance, antimicrobial traits, antidiabetic aspects, cholesterol reduction and adhesion, adhesion to Caco-2 cells, and milk acidification potential). The results showed that 49, out of the 93 retrieved isolates, exhibited resistance to GI conditions, whereas 18 met the safety criteria. The molecular identification revealed strains belonging to the species Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Lacticaseibacillus rhamnosus, and Lacticaseibacillus paracasei. The selected rod-shaped 14 isolates displayed a potential probiotic character. The best-performing isolates concerning cholesterol assimilation and adhesion, α-glucosidase inhibition, and epithelial adherence were Lpb. plantarum F89, F162, and F254 and Lcb. paracasei F214 and F216, whereas Lcb. paracasei F70 showed potential as a defined strain starter. The present study explores for the first time the biodiversity of traditionally fermented microbial communities in Kefalonian Feta-type cheese, revealing novel potential probiotic strains that can contribute to the development of innovative functional food products.

中文翻译：

---

手工羊乳酪型凯法利尼亚奶酪中的新型益生菌候选物：揭示尚未公开的生物多样性

摘要

本地乳制品乳酸菌 (LAB) 分离物包含发酵剂、辅助剂或候选益生菌的天然来源。在这种情况下，传统上仅使用动物凝乳酶生产的羊乳酪型奶酪是从位于凯法利尼亚岛（希腊）不同地区的五个农场收集的。本研究的主要目的是分离和表征新型 LAB，从而探索凯法隆羊乳酪中未绘制的微生物群落，并鉴定新的潜在益生菌。初步筛选包括初步胃肠道 (GI) 耐受性评估（酸性条件和胆汁盐），然后进行安全性评估（溶血活性和抗生素敏感性）。根据初步筛选，选定的菌株进行了分子鉴定，并进一步研究了其益生菌属性（溶菌酶和酚抗性、抗菌特性、抗糖尿病方面、胆固醇降低和粘附、对 Caco-2 细胞的粘附以及牛奶酸化潜力）。结果显示，在 93 株回收的分离株中，有 49 株表现出对胃肠道条件的抵抗力，而 18 株符合安全标准。分子鉴定显示该菌株属于植物乳杆菌、发酵硅酸杆菌、鼠李糖乳杆菌和副干酪乳杆菌。所选的 14 个杆状分离株显示出潜在的益生菌特性。在胆固醇同化和粘附、α-葡萄糖苷酶抑制和上皮粘附方面表现最好的分离株是Lpb。植物乳杆菌F89、F162 和 F254 以及Lcb。paracasei F214 和 F216，而Lcb。paracasei F70 显示出作为特定菌株起始剂的潜力。本研究首次探索了凯法隆羊乳酪中传统发酵微生物群落的生物多样性，揭示了有助于开发创新功能食品的新型潜在益生菌菌株。