Darwish Amira M G, Allam Marwa G, Shokery Enaam S, Ayad Eman H E
Arid Lands Cultivation Research Institute (ALCRI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria, Egypt.
Food Science Dept., Faculty of Agriculture, Saba Basha, Alexandria University, Alexandria, Egypt.
PLoS One. 2022 Mar 2;17(3):e0263241. doi: 10.1371/journal.pone.0263241. eCollection 2022.
Biological food industry has increased economic importance of new Lactic Acid Bacteria (LAB) with functional aspects such as health promoting and enhanced sensorial traits. The objectives of the present study were the isolation and genotypic characterization (16S rRNA) of new LAB isolates from Egyptian Laban Rayeb, Zabady and mothers' breast milk as potential probiotics. Strains were in vitro and in vivo evaluated for their safety and probiotic health promoting traits in Albino rats then applied into two types of functional dairy products. Three strains Streptococcus thermophilus MH422542, Enterococcus faecium MH422543 and Lactococcus lactis subsp lactis MH422545, were selected from a pool of 82 strains. St. thermophilus showed proteolytic activity and production of Exopolysaccharides (EPS). When evaluated in animal models; the strains showed hypolipidemic effects especially E. faecium that reduced atherogenic indices up to 88%. The strains modulated the gut microbiota by reducing Staphylococcus sp. and coliforms with no adverse effects either on blood parameters, antioxidant enzymes, cancer markers or hepatocytes histological examination. Only E. faecium MH422543 showed an immune response by increased white blood cells (WBC) while lymph and platelets values were not affected. The probiotic strains approved their convenience as starter/ adjunct cultures and enhanced organoleptic properties of the fermented dairy products.
生物食品工业提高了具有促进健康和增强感官特性等功能的新型乳酸菌(LAB)的经济重要性。本研究的目的是从埃及拉班·雷耶布、扎巴迪和母乳中分离新型LAB菌株并进行基因型鉴定(16S rRNA),将其作为潜在的益生菌。在白化大鼠中对菌株进行了体外和体内安全性及益生菌促进健康特性的评估,然后将其应用于两种功能性乳制品中。从82株菌株中筛选出了三株嗜热链球菌MH422542、粪肠球菌MH422543和乳酸乳球菌乳酸亚种MH422545。嗜热链球菌表现出蛋白水解活性并产生胞外多糖(EPS)。在动物模型中进行评估时,这些菌株显示出降血脂作用,尤其是粪肠球菌,其将致动脉粥样硬化指数降低了88%。这些菌株通过减少葡萄球菌属和大肠菌群来调节肠道微生物群,对血液参数、抗氧化酶、癌症标志物或肝细胞组织学检查均无不良影响。只有粪肠球菌MH422543通过增加白细胞(WBC)显示出免疫反应,而淋巴细胞和血小板值未受影响。这些益生菌菌株证明了它们作为发酵剂/辅助培养物的适用性,并增强了发酵乳制品的感官特性。