Abstract Bacteriocin LS2 was isolated from the Lactobacillus salivarius BGHO1 strain in 2012. Since then, its antibacterial activity has not been examined. Here, Chlamydomonas reinhardtii was used to express a C-terminal hemagglutinin (HA) and 6×His double tagged three repeats of Bacteriocin LS2 (3×Bacteriocin LS2). 3×Bacteriocin LS2 expression was stable following passaging in C. reinhardtii cells for six months and its yield accounted for 0.28% of total soluble proteins of the host cells. C. reinhardtii-derived 3×Bacteriocin LS2 inhibited the growth of four tested bacteria of both gram-positive and gram-negative with minimum inhibitory concentration (MIC) values between 75 and 90 μg/mL, indicating that this peptide is more potent than other bacteriocins like nesin and bacteriocin MA047A which have a MIC beyond 165 μg/mL in general. The recombinant 3×Bacteriocin LS2 maintained high stability over a wide range of temperature and pHs, showed tolerance to proteases, exhibited low hemolytic activity against rabbit erythrocytes and low cytotoxicity to human embryonic kidney 293 T (HEK 293 T) cells. In addition, C. reinhardtii-derived 3×Bacteriocin LS2 penetrated cell membranes and destroyed the morphology of targeted bacterial cells to different extents. In summary, our study shows that C. reinhardtii can be used as a platform for the production of active Bacteriocin LS2.

中文翻译：

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莱茵衣藻表达的细菌素 LS2 多聚体有效抑制细菌生长

摘要 细菌素LS2于2012年从唾液乳杆菌BGHO1菌株中分离得到，其抗菌活性未见研究。在这里，莱茵衣藻被用来表达 C 端血凝素 (HA) 和 6×His 双标记的细菌素 LS2 (3×细菌素 LS2) 的三个重复。3×细菌素LS2在莱茵衣藻细胞中传代6个月后表达稳定，其产量占宿主细胞总可溶性蛋白的0.28%。C. reinhardtii 衍生的 3×Bacteriocin LS2 抑制四种革兰氏阳性和革兰氏阴性菌的生长，最小抑制浓度 (MIC) 值介于 75 和 90 μg/mL 之间，表明该肽比其他肽更有效细菌素，如 nesin 和细菌素 MA047A，其 MIC 通常超过 165 μg/mL。重组 3×细菌素 LS2 在较宽的温度和 pH 范围内保持高稳定性，对蛋白酶具有耐受性，对兔红细胞表现出低溶血活性，对人胚肾 293 T (HEK 293 T) 细胞具有低细胞毒性。此外，莱茵衣藻来源的 3×Bacteriocin LS2 穿透细胞膜并不同程度破坏了目标细菌细胞的形态。总之，我们的研究表明莱茵衣藻可作为生产活性细菌素 LS2 的平台。Reinhardtii 来源的 3×Bacteriocin LS2 穿透细胞膜并不同程度破坏目标细菌细胞的形态。总之，我们的研究表明莱茵衣藻可作为生产活性细菌素 LS2 的平台。Reinhardtii 来源的 3×Bacteriocin LS2 穿透细胞膜并不同程度破坏目标细菌细胞的形态。总之，我们的研究表明莱茵衣藻可作为生产活性细菌素 LS2 的平台。