Post-Graduate Department of Biosciences, UGC Centre of Advanced Study, Sardar Patel University, Mota Bazaar, Vallabh Vidyanagar 388120, Anand, Gujarat, India.
P.D. Patel Institute of Applied Sciences, Charotar University of Science & Technology (CHARUSAT), Highway, Off, Nadiad-Petlad Rd, Changa 388421, Gujarat, India.
J Appl Microbiol. 2023 Feb 16;134(2). doi: 10.1093/jambio/lxac057.
The current study aimed to scrutinize the probiotic traits and safety aspects of Bacillus velezensis K1 through experimental and supporting genome studies.
The seven cultures previously isolated from the aerial roots of Ficus benghalensis were initially screened for their antibacterial activity as well as acid and bile tolerance. The isolate K1 was found to be the most potent and was further investigated for probiotic traits and safety. K1 showed tolerance to simulated digestive juices and 0.3% bile. It showed notable aggregation, cell surface hydrophobicity, and adherence to HT-29 cells. K1 significantly prevented the adhesion of E. coli O157: H7 and S. enterica ATCC 13076 to HT-29 in cell culture assays. K1 could hydrolyze phytate and complex polysaccharides. The genes related to stress tolerance, adhesion, antimicrobial activity, and production of vitamins, viz. thiamine, riboflavin, pyridoxine, pantothenic acid, folate, and biotin were annotated in the K1 genome. K1 was found to be non-hemolytic, noncytotoxic, as well as susceptible to antibiotics. No virulence or toxin-encoding genes were identified in its genome.
B. velezensis K1 is a prospective probiotic with the ability to tolerate gastrointestinal stress, adhere to intestinal surfaces, and inhibit enteropathogens.
本研究通过实验和支持基因组学研究，旨在仔细研究解淀粉芽孢杆菌 K1 的益生菌特性和安全性方面。
最初从榕属植物气生根中分离出的 7 株菌进行了抗菌活性以及酸和胆汁耐受性的初步筛选。发现菌株 K1 具有最强的活性，进一步研究了其益生菌特性和安全性。K1 对模拟消化液和 0.3%胆汁具有耐受性。它表现出明显的聚集、细胞表面疏水性和对 HT-29 细胞的黏附性。K1 显著抑制了 E. coli O157: H7 和 S. enterica ATCC 13076 在细胞培养试验中与 HT-29 的黏附。K1 可以水解植酸和复杂多糖。与应激耐受、黏附、抗菌活性以及维生素（硫胺素、核黄素、吡哆醇、泛酸、叶酸和生物素）生产相关的基因在 K1 基因组中被注释。K1 无溶血、细胞毒性，并且对抗生素敏感。其基因组中未发现毒力或毒素编码基因。
B. velezensis K1 是一种具有耐受胃肠道应激、黏附肠道表面和抑制肠道病原体能力的有前景的益生菌。
