Data_Sheet_1_In vitro screening and characterization of lactic acid bacteria from Lithuanian fermented food with potential probiotic properties.DOCX

The present work aimed to identify probiotic candidates from Lithuanian homemade fermented food samples. A total of 23 lactic acid bacteria were isolated from different fermented food samples. Among these, only 12 showed resistance to low pH, tolerance to pepsin, bile salts, and pancreatin. The 12 strains also exhibited antimicrobial activity against Staphylococcus aureus ATCC 29213, Salmonella Typhimurium ATCC 14028, Streptococcus pyogenes ATCC 12384, Streptococcus pyogenes ATCC 19615, and Klebsiella pneumoniae ATCC 13883. Cell-free supernatants of isolate 3A and 55w showed the strongest antioxidant activity of 26.37 μg/mL and 26.06 μg/mL, respectively. Isolate 11w exhibited the strongest auto-aggregation ability of 79.96% as well as the strongest adhesion to HCT116 colon cells (25.671 ± 0.43%). The selected strains were tested for their synbiotic relation in the presence of a prebiotic. The selected candidates showed high proliferation in the presence of 4% as compared to 2% galactooligosaccharides. Among the strains tested for tryptophan production ability, isolate 11w produced the highest L-tryptophan levels of 16.63 ± 2.25 μm, exhibiting psychobiotic ability in the presence of a prebiotic. The safety of these strains was studied by ascertaining their antibiotic susceptibility, mucin degradation, gelatin hydrolysis, and hemolytic activity. In all, isolates 40C and 11w demonstrated the most desirable probiotic potentials and were identified by 16S RNA and later confirmed by whole genome sequencing as Lacticaseibacillus paracasei 11w, and Lactiplantibacillus plantarum 40C: following with the harboring plasmid investigation. Out of all the 23 selected strains, only Lacticaseibacillus paracasei 11w showed the potential and desirable probiotic properties.

本研究旨在从立陶宛自制发酵食品样本中筛选益生菌候选菌株。研究人员总计从不同发酵食品样本中分离得到23株乳酸菌（lactic acid bacteria）。其中仅12株能够耐受低pH环境、胃蛋白酶、胆汁盐及胰酶。这12株菌株同时对金黄色葡萄球菌（Staphylococcus aureus）ATCC 29213、鼠伤寒沙门氏菌（Salmonella Typhimurium）ATCC 14028、化脓性链球菌（Streptococcus pyogenes）ATCC 12384、化脓性链球菌ATCC 19615以及肺炎克雷伯菌（Klebsiella pneumoniae）ATCC 13883具有抗菌活性。菌株3A与55w的无细胞上清液抗氧化活性最强，分别达26.37 μg/mL和26.06 μg/mL。菌株11w的自凝集能力最为突出，为79.96%，同时对HCT116结肠癌细胞的黏附能力也最强，达25.671±0.43%。研究人员对筛选得到的菌株开展了益生元存在下的合生素（synbiotic）相关特性测试：相较于2%低聚半乳糖（galactooligosaccharides），4%浓度的低聚半乳糖可使这些候选菌株实现更高水平的增殖。在针对色氨酸生成能力的测试中，菌株11w的L-色氨酸产量最高，为16.63±2.25 μm，且在益生元存在下展现出精神益生菌（psychobiotic）活性。通过检测抗生素敏感性、黏蛋白降解、明胶水解及溶血活性，对上述菌株的安全性进行了评估。总体而言，菌株40C与11w展现出最优异的益生菌应用潜能，经16S RNA初步鉴定后，通过全基因组测序分别确认为副干酪乳杆菌（Lacticaseibacillus paracasei）11w以及植物乳杆菌（Lactiplantibacillus plantarum）40C；后续还对其携带的质粒进行了分析。在全部23株分离菌株中，仅副干酪乳杆菌11w兼具所有理想的益生菌特性。