Borthakur Debashree, Sharma Bipin Kumar, Upadhye Vijay Jagdish
Department of Microbiology, Tripura University, Tripura, 799022, Suryamaninagar, India.
Department of Bio-Sciences, Assam Don Bosco University, 781017, Assam, Guwahati, India.
BMC Microbiol. 2025 Sep 24;25(1):579. doi: 10.1186/s12866-025-04312-w.
Teles is a traditional fermented food native to Assam, India, valued for its unique aroma and potential health benefits. Despite its cultural importance, the beneficial microbial communities in Teles remain poorly characterised, particularly with respect to probiotic functionality and food-enhancing properties. This study aimed to isolate and characterize microbial strains from Teles for their probiotic potential and aroma-producing capabilities, targeting their application as functional starter cultures in food fermentation.
Bacterial strains were isolated from Teles and evaluated for essential probiotic traits, including tolerance to acid (pH 2.0), salt (8% NaCl), bile (2.0%), and phenol (0.4%). Phenol tolerance-the ability to survive toxic compounds generated during digestion-was used to assess intestinal robustness. Auto-aggregation-the ability of bacteria to clump together-was measured as an indicator of their potential to form stable colonies in the gastrointestinal tract. Adhesion to intestinal surfaces was assessed using chicken crop epithelial cells. Pathogenicity of the isolates was confirmed by screening for haemolytic activity, DNase production, and antibiotic susceptibility. Functional validation involved fermenting milk and rice substrates (to produce curd and rice beverage), followed by gas chromatography-mass spectrometry (GC-MS) analysis of flavour compounds. Strain identification was conducted via 16 S rRNA gene sequencing.
Out of 35 isolates, strain TL/NA/2 (Bacillus sp.; GenBank Accession No. PQ473688.1) emerged as the most functionally promising strain. It exhibited high tolerance to multiple stressors: acid (pH 2.0), 8% NaCl, 2.0% bile, and 0.4% phenol. TL/NA/2 showed a strong self-clumping ability (27.88 ± 1.04% auto-aggregation after 5 h) and adhered well to epithelial cells (84.19 ± 1.28%). The strain was non-haemolytic, DNase-negative, and sensitive to several clinically relevant antibiotics. GC-MS profiling revealed production of beneficial flavour compounds including pyrazine, heptane, and oxalic acid. Sensory evaluation of the fermented products confirmed improved flavour and overall acceptability.
Strain TL/NA/2 (Bacillus sp.) demonstrates strong probiotic potential along with the capacity to enhance flavour, making it a suitable multifunctional starter culture for developing functional fermented foods and beverages. Its stress resilience, safety profile, and sensory benefits position it as a promising candidate for industrial probiotic applications.
特莱斯是一种原产于印度阿萨姆邦的传统发酵食品，因其独特的香气和潜在的健康益处而受到重视。尽管它具有文化重要性，但特莱斯中有益的微生物群落仍未得到充分表征，特别是在益生菌功能和食品增强特性方面。本研究旨在从特莱斯中分离和表征微生物菌株，以评估其益生菌潜力和产香能力，目标是将其用作食品发酵中的功能性发酵剂。
从特莱斯中分离细菌菌株，并评估其基本的益生菌特性，包括对酸（pH 2.0）、盐（8%氯化钠）、胆汁（2.0%）和苯酚（0.4%）的耐受性。苯酚耐受性——在消化过程中耐受产生的有毒化合物的能力——用于评估肠道稳健性。自聚集——细菌聚集在一起的能力——被测量作为它们在胃肠道中形成稳定菌落潜力的指标。使用鸡嗉囊上皮细胞评估对肠表面的粘附。通过筛选溶血活性、DNA酶产生和抗生素敏感性来确认分离株的致病性。功能验证包括发酵牛奶和大米底物（以生产凝乳和大米饮料），然后对风味化合物进行气相色谱 - 质谱（GC-MS）分析。通过16S rRNA基因测序进行菌株鉴定。
在35株分离株中，菌株TL/NA/2（芽孢杆菌属；GenBank登录号PQ473688.1）成为功能上最有前景的菌株。它对多种应激源表现出高耐受性：酸（pH 2.0）、8%氯化钠、2.0%胆汁和0.4%苯酚。TL/NA/2表现出很强的自聚集能力（5小时后自聚集率为27.88±1.04%），并且与上皮细胞粘附良好（84.19±1.28%）。该菌株无溶血活性、DNA酶阴性，并且对几种临床相关抗生素敏感。GC-MS分析表明产生了包括吡嗪、庚烷和草酸在内的有益风味化合物。发酵产品的感官评价证实了风味的改善和总体可接受性。
菌株TL/NA/2（芽孢杆菌属）具有很强的益生菌潜力以及增强风味的能力，使其成为开发功能性发酵食品和饮料的合适多功能发酵剂。其抗逆性、安全性和感官益处使其成为工业益生菌应用的有前途的候选者。
