Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island 627833, Singapore.
Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island 627833, Singapore.
Biotechnol Adv. 2018 Dec;36(8):2187-2200. doi: 10.1016/j.biotechadv.2018.10.007. Epub 2018 Oct 29.
Bacteriocins are low molecular weight peptides secreted by the predator bacterial cells to kill sensitive cells present in the same ecosystem competing for food and other nutrients. Exceptionally few bacteriocins along with their native antibacterial property also exhibit additional anti-viral and anti-fungal properties. Bacteriocins are generally produced by Gm+, Gm- and archaea bacteria. Bacteriocins from Gm + bacteria especially from lactic acid bacteria (LAB) have been thoroughly investigated considering their great biosafety and broad industrial applications. LAB expressing bacteriocins were isolated from fermented milk and milk products, rumen of animals and soil using deferred antagonism assay. Nisin is the only bacteriocin that has got FDA approval for application as a food preservative, which is produced by Lactococcus lactis subsp. Lactis. Its crystal structure explains that its antimicrobial properties are due to the binding of NH terminal to lipid II molecule inhibiting the peptidoglycan synthesis and carboxy terminal forming pores in bacterial cell membrane leading to cell lysis. The hinge region connecting NH and carboxy terminus has been mutated to generate mutant variants with higher antimicrobial activity. In a 50 ton fermentation of the mutant strain 3807 derived from L. lactis subsp. lactis ATCC 11454, 9,960 IU/mL of nisin was produced. Currently, high purity of nisin (>99%) is very expensive and hardly commercially available. Development of more advanced tools for cost-effective separation and purification of nisin would be commercially attractive. Chemical synthesis and heterologous expression of bacteriocins ended in low yields of pure proteins. At present, bacteriocins are almost solely applied in food industries, but they have a great potential to be used in other fields such as feeds, organic fertilizers, environmental protection and personal care products. The future of bacteriocins is largely dependent on getting FDA approval for use of other bacteriocins in addition to nisin to promote the research and applications.
细菌素是由捕食性细菌细胞分泌的低分子量肽，用于杀死存在于同一生态系统中、争夺食物和其他营养物质的敏感细胞。极少数细菌素除了具有天然的抗菌特性外，还具有额外的抗病毒和抗真菌特性。细菌素通常由 Gm+、Gm-和古菌细菌产生。考虑到其巨大的生物安全性和广泛的工业应用，来自 Gm+细菌的细菌素，特别是来自乳酸菌（LAB）的细菌素，已经得到了彻底的研究。通过延迟拮抗试验，从发酵乳和乳制品、动物瘤胃和土壤中分离出表达细菌素的 LAB。乳链菌肽是唯一一种获得 FDA 批准作为食品防腐剂应用的细菌素，由乳球菌乳亚种。其晶体结构解释了其抗菌特性是由于 NH 末端与脂质 II 分子结合，抑制肽聚糖合成，羧基末端在细菌细胞膜中形成孔，导致细胞裂解。连接 NH 和羧基末端的铰链区发生突变，产生具有更高抗菌活性的突变体。在来自乳球菌乳亚种的突变株 3807 的 50 吨发酵中，生产了 9960 IU/mL 的乳链菌肽。目前，高纯度的乳链菌肽（>99%）非常昂贵，几乎无法在商业上获得。开发更先进的工具，以具有成本效益的方式分离和纯化乳链菌肽，将具有商业吸引力。细菌素的化学合成和异源表达最终导致纯蛋白的产量很低。目前，细菌素几乎完全应用于食品工业，但它们在饲料、有机肥料、环境保护和个人护理产品等其他领域有很大的应用潜力。除了乳链菌肽外，其他细菌素获得 FDA 批准用于促进研究和应用，将在很大程度上决定细菌素的未来。
