Kinema,喜马拉雅山传统的发酵大豆食品,因其粘稠的质地和美味的鲜味而备受喜爱。在来自自发发酵的kinema样品的175个细菌菌株中,枯草芽孢杆菌Tamang菌株因其高粘性和粘度而脱颖而出。该菌株的聚-γ-谷氨酸(γ-PGA)含有各种谷氨酸基团,分子量为660kDa。它证明了溶解铁的能力,在Caco-2细胞中保存铁蛋白,并表现出抗菌性能。枯草芽孢杆菌Tamang的基因组没有质粒元件,但具有9个插入元件。值得注意的是存在具有潜在抗菌作用的独特次级代谢产物,如淀粉样蛋白GF610,波哥罗A,总共鉴定了132种碳水化合物活性酶(CAZy),暗示可能的益生元特征。基因组分析揭示了负责通过capBCA复合物产生γ-PGA的基因。此外,与纤溶活性相关的基因,味道增强,生物肽,免疫调节剂,发现了维生素B12和K2,以及益生菌和各种健康益处。生产L-天冬酰胺酶的遗传物质,以其抗癌特性而闻名,也被检测到,以及CRISPR-Cas系统。缺乏毒力因子和抗微生物抗性基因证实了食用枯草芽孢杆菌Tamang作为食品级细菌的安全性。
Kinema, a traditional fermented soybean food from the Himalayas, is well-liked for its sticky texture and flavourful umami taste. Among 175 bacterial strains from spontaneously fermented kinema samples, Bacillus subtilis Tamang strain stood out for its high stickiness and viscosity. The strain\'s Poly-γ-glutamic acid (γ-PGA) contains various groups of glutamic acid and has a molecular weight of 660 kDa. It demonstrates the ability to solubilize iron, preserve ferritin in Caco-2 cells, and exhibit antibacterial properties. The genome of B. subtilis Tamang is devoid of plasmid elements but does feature nine insert elements. Noteworthy is the presence of unique secondary metabolites with potential antimicrobial effects, such as amyloliquecidin GF610, bogorol A, and thermoactinoamide A. A total of 132 carbohydrate-active enzymes (CAZy) were identified, hinting at possible prebiotic characteristics. The genome analysis revealed genes responsible for γ-PGA production via the capBCA complex. Furthermore, genes associated with fibrinolytic activity, taste enhancement, biopeptides, immunomodulators, and vitamins like B12 and K2 were found, along with probiotics and various health benefits. The genetic material for L-asparaginase production, known for its anti-cancer properties, was also detected, as well as CRISPR-Cas systems. The absence of virulence factors and antimicrobial resistance genes confirms the safety of consuming B. subtilis Tamang as a food-grade bacterium.