Lei Shuang, Zhao Ruixiang, Sun Junliang, Ran Junjian, Ruan Xiaoli, Zhu Yang
School of Food Science Henan Institute of Science and Technology Xinxiang China.
Wageningen University and Research Centre Wageningen The Netherlands.
Food Sci Nutr. 2020 Mar 18;8(5):2214-2222. doi: 10.1002/fsn3.1428. eCollection 2020 May.
zrx03 was a bacteriocin-producing strain isolated from infant's feces. The fermentation supernatant produced by this strain could strongly inhibit JM109 ATCC 67387, ATCC 25923, and CICC 21633, in which the diameter of inhibition zone was 12.83 ± 0.62 mm, 15.08 ± 0.31 mm, 6.75 ± 0.20 mm, respectively, compared with lactic acid bacteria N1, N2, M13, M21, M31, and M37. According to amplification of 16S rRNA gene and identification of phylogenetic tree, this strain had a 1,450 bp sequence and 100% identity to the strain. Based on the influence of different protease treatments, such as pepsin, trypsin, papain, and proteinase K on the antimicrobial activity, this antimicrobial substance was considered to be a natural protein. Using bacteriocin produced by this strain as study object of this experiment, it had been extracted from ammonium sulfate precipitation and different organic solvents. The results showed that ethyl acetate was selected as the optimal solution to crude extraction of bacteriocin after comparing ammonium sulfate precipitation method and organic solvent extraction method, such as n-butanol, n-hexane, dichloromethane, trichloromethane, in which the diameter of the inhibition zones was above 28 mm. Results also showed the inhibition spectrum of the obtained bacteriocin had a broad spectrum of inhibition which could inhibit Gram-positive, Gram-negative, yeast. Especially, it could effectively inhibit ATCC 25923, CICC 10002, CICC 20443, JM109 ATCC 67387, and CMCC 541, and the zone diameter of inhibition has reached more than 28 mm. Moreover, it had a good thermal stability which antibacterial activity was retained 70.58% after treatment at 121°C for 30 min, and pH-stability was between pH 2.0-9.0. These results suggested bacteriocin produced by zrx03 had potential application prospects in food preservation.
zrx03是从婴儿粪便中分离出的一株产细菌素的菌株。该菌株产生的发酵上清液能强烈抑制JM109 ATCC 67387、ATCC 25923和CICC 21633，与乳酸菌N1、N2、M13、M21、M31和M37相比，其抑菌圈直径分别为12.83±0.62毫米、15.08±0.31毫米、6.75±0.20毫米。通过16S rRNA基因扩增和系统发育树鉴定，该菌株有一个1450 bp的序列，与该菌株的序列一致性为100%。基于胃蛋白酶、胰蛋白酶、木瓜蛋白酶和蛋白酶K等不同蛋白酶处理对抗菌活性的影响，这种抗菌物质被认为是一种天然蛋白质。以该菌株产生的细菌素作为本实验的研究对象，通过硫酸铵沉淀和不同有机溶剂对其进行了提取。结果表明，在比较硫酸铵沉淀法和正丁醇、正己烷、二氯甲烷、三氯甲烷等有机溶剂提取法后，乙酸乙酯被选为粗提细菌素的最佳溶剂，其抑菌圈直径在28毫米以上。结果还表明，所获得的细菌素的抑菌谱具有广谱性，能抑制革兰氏阳性菌、革兰氏阴性菌和酵母菌。特别是，它能有效抑制ATCC 25923、CICC 10002、CICC 20443、JM109 ATCC 67387和CMCC 541，抑菌圈直径达到28毫米以上。此外，它具有良好的热稳定性，在121℃处理30分钟后抗菌活性保留70.58%，pH稳定性在pH 2.0 - 9.0之间。这些结果表明zrx03产生的细菌素在食品保鲜方面具有潜在的应用前景。
