Present study is intended to assess the probiotic properties of Bacillus spp. isolated from idli batter, a traditional fermented food of Southern India and Sri Lanka. A total of 32 isolates were screened for potential pathogenic behaviour through haemolysis assay, DNase activity and antibiotics sensitivity. Two of the isolates were found to be potentially safe and identified as Bacillus spp. These strains were characterized for in vitro probiotic attributes and antioxidant activity. Both the strains showed strong acid and bile tolerance, transit tolerance, lysozyme tolerance, cell surface hydrophobicity, auto-aggregation, co-aggregation, biofilm formation potential and adhesion to human colon adenocarcinoma (HT 29) cell line demonstrating potential probiotic ability. These strains also exhibited considerable cholesterol binding, thermostability, β-galactosidase production, proteolytic, amylolytic and lipolytic activity. Cell-free supernatant inhibited the biofilm formation by Pseudomonas aeruginosa (KT266804) to 90%. Intact cells showed significant DPPH (41%), hydroxyl (31%), radical scavenging activity and lipid peroxidation inhibition (20.38%), while cell-free extracts exhibited significant superoxide anion radical scavenging activity (16.25%). Results revealed that isolates could be potential probiotic candidate after further assessment of in vivo probiotic properties and safety evaluation and could be utilised as starter cultures in functional foods.

中文翻译：

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从酸性发酵食品Idli分离的芽孢杆菌菌株的益生菌潜力。

本研究旨在评估芽孢杆菌的益生菌特性。分离自印度南部和斯里兰卡的传统发酵食品idli batter。通过溶血分析，DNase活性和抗生素敏感性，共筛选了32个分离株的潜在病原学行为。发现其中两个分离株具有潜在的安全性，被鉴定为芽孢杆菌。这些菌株具有体外益生菌特性和抗氧化活性。两种菌株均显示出强酸和胆汁耐受性，转运耐受性，溶菌酶耐受性，细胞表面疏水性，自聚集，共聚集，生物膜形成潜能以及对人结肠腺癌（HT 29）细胞系的粘附性，证明了其潜在的益生菌能力。这些菌株还表现出可观的胆固醇结合，热稳定性，β-半乳糖苷酶的产生，蛋白水解，淀粉分解和脂解活性。无细胞上清液将铜绿假单胞菌（KT266804）的生物膜形成抑制到90％。完整细胞表现出显着的DPPH（41％），羟基（31％），自由基清除活性和脂质过氧化抑制（20.38％），而无细胞提取物则表现出显着的超氧阴离子自由基清除活性（16.25％）。结果表明，在进一步评估体内益生菌特性和安全性评估后，分离株可能是潜在的益生菌候选物，并且可以用作功能性食品中的发酵剂。自由基清除活性和脂质过氧化抑制作用（20.38％），而无细胞提取物则表现出显着的超氧阴离子自由基清除活性（16.25％）。结果表明，在进一步评估体内益生菌特性和安全性评估后，分离株可能是潜在的益生菌候选物，并且可以用作功能性食品中的发酵剂。自由基清除活性和脂质过氧化抑制作用（20.38％），而无细胞提取物则表现出显着的超氧阴离子自由基清除活性（16.25％）。结果表明，在进一步评估体内益生菌特性和安全性评估后，分离株可能是潜在的益生菌候选物，并且可以用作功能性食品中的发酵剂。