Botany & Microbiology Department (Girls Branch), Faculty of Science, Al-Azhar University, Cairo, Egypt.
Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, People's Republic of China.
World J Microbiol Biotechnol. 2023 Mar 13;39(5):114. doi: 10.1007/s11274-023-03556-w.
In this investigation, lactic acid bacteria (LAB) isolated from milk were tested for their antibacterial properties and improved the antimicrobial activity of these isolates using genome shuffling. A total of sixty-one isolates were found in eleven samples, which were then tested using the agar diffusion method for their antibacterial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. Thirty-one strains exhibited antibacterial activity against at least one of the tested pathogens, with an inhibitory zone's diameter varying between 15.0 and 24.0 mm. Two isolates that showed the highest antimicrobial activity were identified as Lactobacillus plantarum CIP 103151 and Lactobacillus plantarum JCM 1149 according to 16S rRNA analysis. In the present study, applying genome shuffling approach significantly enhanced the antibacterial activity of L. plantarum. The initial populations were obtained via ultraviolet irradiation and were treated using the protoplast fusion method. The ideal condition for the production of protoplasts was 15 mg/ml of lysozyme and 10 μg/ml of mutanolysin. After two rounds of fusion, ten recombinants exhibited a significant increase in the inhibition zones versus S. aureus, S. typhimurium, P. aeruginosa, and E. coli, reaching up to 1.34, 1.31, 1.37, and 1.37-fold increase in inhibitory zone respectively. Random Amplified Polymorphic DNA results showed clear differences in DNA banding patterns among the wild strain of L. plantarum CIP 103151 and the three selected shuffled strains using primers 1283 & OPA09. On the other hand, no change was obtained using primers OPD03 neither among the wild strain and the three recombinant strains nor among the three shuffled strains.
在这项研究中，对从牛奶中分离出的乳酸菌（LAB）进行了抗菌特性测试，并使用基因组改组来提高这些分离物的抗菌活性。在 11 个样本中发现了 61 个分离物，然后使用琼脂扩散法测试它们对金黄色葡萄球菌、大肠杆菌、鼠伤寒沙门氏菌和铜绿假单胞菌的抗菌活性。31 株对至少一种测试病原体具有抗菌活性，抑菌圈直径在 15.0 至 24.0 毫米之间。根据 16S rRNA 分析，两种表现出最高抗菌活性的分离物被鉴定为植物乳杆菌 CIP 103151 和植物乳杆菌 JCM 1149。在本研究中，应用基因组改组方法显著提高了植物乳杆菌的抗菌活性。初始种群是通过紫外线照射获得的，并通过原生质体融合法进行处理。产生原生质体的理想条件是 15mg/ml 的溶菌酶和 10μg/ml 的溶菌酶。经过两轮融合，十个重组体对金黄色葡萄球菌、鼠伤寒沙门氏菌、铜绿假单胞菌和大肠杆菌的抑制圈明显增加，分别达到抑制圈的 1.34、1.31、1.37 和 1.37 倍。随机扩增多态性 DNA 结果表明，在使用引物 1283 和 OPA09 时，野生型植物乳杆菌 CIP 103151 与三种选择的改组菌株之间的 DNA 带型模式存在明显差异。另一方面，使用引物 OPD03 时，野生株和三种重组株之间以及三种改组株之间均未获得变化。
