Liu Guorong, Wang Yao, Li Xue, Hao Xu, Xu Duoxia, Zhou Yingning, Mehmood Arshad, Wang Chengtao
Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, Beijing, China.
Beijing Academy of Agricultural and Forestry Sciences, Beijing, China.
Front Microbiol. 2019 Aug 13;10:1806. doi: 10.3389/fmicb.2019.01806. eCollection 2019.
Bacteriocins are ribosomally synthesized antibacterial peptides or proteins from microorganisms. We report a novel bacteriocin producing strain, Gr17, that was isolated from the Chinese traditional low-salt fermented whole fish product Suan yu. Gr17 displayed potent antibacterial activity against foodborne pathogenic and spoilage bacteria. The complete genome of Gr17 contained one circular chromosome and plasmid. The gene cluster of a novel bacteriocin designated enterocin Gr17 was identified. The enterocin Gr17 structural gene encodes a precursor of the bacteriocin. Two other transporter genes and an immunity gene within two divergent operons were identified as being associated with enterocin Gr17 secretion and protection. The novel enterocin Gr17 was purified by ammonium sulfate precipitation, cation exchange, gel filtration, and reverse-phase high-performance liquid chromatography. The molecular weight of enterocin Gr17 was 4,531.01 Da as determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and its mature amino acid sequence of enterocin Gr17 was RSYGNGVYCNNSKCWVNWGEAKENIIGIVISGWATGLAGMGR. Sequence alignment revealed that enterocin Gr17 is a class IIa bacteriocin with similarities to enterocin P. The merits of bactericidal activity, sensitivity to enzymes, and pronounced stability to chemicals, temperature (60°C, 30 min and 121°C, 15 min), and pH (2-10) indicated practicality and safety of enterocin Gr17 in the food industry. The complete genome information of Gr17 will improve the understanding of the biosynthetic mechanism of enterocin Gr17, which has potential value as a food biopreservative.
细菌素是微生物核糖体合成的抗菌肽或蛋白质。我们报道了一株新的细菌素产生菌株Gr17，它是从中国传统低盐发酵全鱼制品酸鱼中分离出来的。Gr17对食源性病原体和腐败菌表现出强大的抗菌活性。Gr17的完整基因组包含一条环状染色体和质粒。鉴定出一个名为肠球菌素Gr17的新型细菌素基因簇。肠球菌素Gr17结构基因编码细菌素的前体。在两个不同的操纵子中鉴定出另外两个转运基因和一个免疫基因与肠球菌素Gr17的分泌和保护有关。新型肠球菌素Gr17通过硫酸铵沉淀、阳离子交换、凝胶过滤和反相高效液相色谱法进行纯化。通过基质辅助激光解吸/电离飞行时间质谱法测定，肠球菌素Gr17的分子量为4531.01 Da，其成熟氨基酸序列为RSYGNGVYCNNSKCWVNWGEAKENIIGIVISGWATGLAGMGR。序列比对显示肠球菌素Gr17是一种与肠球菌素P相似的IIa类细菌素。其杀菌活性、对酶的敏感性以及对化学物质、温度（60°C，30分钟和121°C，15分钟）和pH（2-10）具有显著稳定性等优点表明肠球菌素Gr17在食品工业中具有实用性和安全性。Gr17的完整基因组信息将增进对肠球菌素Gr17生物合成机制的理解，其作为食品生物防腐剂具有潜在价值。
