Daba Ghoson M, Elkhateeb Waill A, Saleh Shireen A A, Soliman Tarek N, El-Dein Asmaa Negm
Chemistry of Natural and Microbial Products Department, National Research Centre, El Buhouth St., Dokki, Giza, 12311, Egypt.
Dairy Department, Food Industries and Nutrition Research Institute, National Research Centre, El-Buhouth St., Dokki, Giza, Egypt.
Microb Cell Fact. 2025 Jan 13;24(1):18. doi: 10.1186/s12934-024-02631-7.
Functional foods and dairy products are gaining global attention due to their nutritional value and health-promoting characteristics. Lactic acid bacteria (LAB) are one of the promising components included in these products, thanks to their probiotic properties and ability to produce bioactive compounds such as bacteriocins. On the other hand, ectomycorrhizal wild mushrooms (truffles) are known for their ethnomycological importance. Hence, we aimed to develop a functional dairy product using a bacteriocin-producing LAB isolate that has probiotic potentials together with the bioactive extract of a truffle mushroom.
Screening for bacteriocin-producing LAB led to the selection of four safe isolates that also showed promising probiotic potentials. Isolate No. 7 was selected due to its wider antimicrobial spectrum and was identified as Lactiplantibacillus plantarum strain GA7. Out of resulting bands from Tricine SDS-PAGE analysis, a band (its molecular mass was approximately 7 kDa) exhibited antimicrobial activity. Amino acid sequencing of this active band detected 62 amino acid residues with 100% identity to plantaricin ASM1 bacteriocin. Simultaneously, an ethyl acetate extract was prepared from a truffle sample identified as Tirmania pinoyi. Safety of this truffle was confirmed and its extract exerted promising antioxidant and hypocholesterolemic activity. Prepared functional dairy products (Labneh) fortified with L. plantarum GA7 and nano-encapsulated T. pinoyi extract exhibited superior physicochemical, sensory and antioxidant properties compared to control. Moreover, an increase in probiotic count was observed in presence of T. pinoyi extract. Furthermore, prepared Labneh using the bacteriocin-producing L. plantarum GA7 and nano-encapsulated T. pinoyi extract remained unspoiled for over 60 days, compared to control, which spoiled after 21 days.
Besides improving Labneh physicochemical, sensory and antioxidant properties, the presence of the bacteriocin-producing L. plantarum GA7 has contributed in significantly extending its shelf life, while T. pinoyi extract showed prebiotic influence on probiotic count. As far as we know this is the first study describing production of a functional synbiotic dairy product fortified with bacteriocin-producing probiotic LAB and bioactive T. pinoyi truffle extract.
功能性食品和乳制品因其营养价值和促进健康的特性而受到全球关注。乳酸菌(LAB)是这些产品中颇具前景的成分之一,这得益于它们的益生菌特性以及产生细菌素等生物活性化合物的能力。另一方面,外生菌根野生蘑菇(块菌)因其在民族真菌学上的重要性而闻名。因此,我们旨在开发一种功能性乳制品,使用一种具有益生菌潜力且能产生细菌素的LAB分离株,同时添加块菌蘑菇的生物活性提取物。
对产细菌素的LAB进行筛选后,选出了四种安全的分离株,它们也显示出有前景的益生菌潜力。由于其抗菌谱更广,选择了7号分离株,并鉴定为植物乳杆菌GA7菌株。在Tricine SDS - PAGE分析得到的条带中,一条带(其分子量约为7 kDa)表现出抗菌活性。对这条活性带进行氨基酸测序,检测到62个氨基酸残基,与植物乳杆菌素ASM1细菌素100%相同。同时,从鉴定为皮诺蒂尔马尼亚菌的块菌样本中制备了乙酸乙酯提取物。确认了这种块菌的安全性,其提取物表现出有前景的抗氧化和降胆固醇活性。用植物乳杆菌GA7和纳米包封的皮诺蒂尔马尼亚菌提取物强化制备的功能性乳制品(拉布内奶酪)与对照相比,在理化、感官和抗氧化特性方面表现更优。此外,在存在皮诺蒂尔马尼亚菌提取物的情况下,观察到益生菌数量增加。此外,与21天后变质的对照相比,使用产细菌素的植物乳杆菌GA7和纳米包封的皮诺蒂尔马尼亚菌提取物制备的拉布内奶酪在60多天内未变质。
除了改善拉布内奶酪的理化、感官和抗氧化特性外,产细菌素的植物乳杆菌GA7的存在显著延长了其保质期,而皮诺蒂尔马尼亚菌提取物对益生菌数量显示出益生元影响。据我们所知,这是第一项描述用产细菌素的益生菌LAB和生物活性皮诺蒂尔马尼亚菌块菌提取物强化制备功能性合生元乳制品的研究。