过氧化氢对鲜湿粉条中优势腐败菌阿氏芽孢杆菌的抑菌活性及机制

Antibacterial Activity and Mechanism of Hydrogen Peroxide against the Dominant Strain Bacillus aryabhattai in Fresh and Wet Vermicelli

为抑制鲜湿粉条中微生物的腐败变质以及探索绿色高效的保鲜剂,本研究系统探究了过氧化氢(H_(2)O_(2))作为一种绿色保鲜剂对鲜湿粉条的优势腐败菌的抑菌机制。首先通过高通量测序确定鲜湿粉条中的优势腐败菌为阿氏芽孢杆菌(Bacillus aryabhattai),再采用抑菌活性实验对H_(2)O_(2)对B. aryabhattai的抑菌圈直径(Inhibition zone diameter,IZD)、最小抑菌浓度(Minimum inhibitory concentration,MIC)、最小杀菌浓度(Minimum bactericidal concentration,MBC)和生长曲线的影响进行分析;同时进行抑菌机制实验观察H_(2)O_(2)对B. aryabhattai的细胞膜、细胞壁的破坏作用及胞内功能成分的外泄。结果表明,当H_(2)O_(2)浓度由250μg/mL提高至1000μg/mL,IZD增大了8 mm,H_(2)O_(2)的MIC和MBC均为250μg/mL。通过生长曲线发现当H_(2)O_(2)浓度高于250μg/mL时能在24 h内完全抑制住细菌的生长。抑菌机制实验表明H_(2)O_(2)的浓度增加会显著提高菌液上清液中核酸、蛋白质的含量(P<0.05),同时破坏了B. aryabhattai的细胞壁和细胞膜结构,导致碱性磷酸酶(Alkaline phosphatase,AKP)和β-半乳糖苷酶(β-Galactosidase,β-GAL)泄露到细胞外,且与H_(2)O_(2)呈浓度依赖性。因此,250μg/mL H_(2)O_(2)能够有效抑制鲜湿粉条中的优势腐败菌B. aryabhattai。本研究可为鲜湿粉条的货架期延长、市值提升提供一定的理论依据和生产指导。

To inhibit microbial spoilage in fresh and wet vermicelli and explore green and efficient preservatives,this study systematically investigated the antibacterial mechanism of hydrogen peroxide(H_(2)O_(2)),a green preservative,against the predominant spoilage bacteria in fresh and wet vermicelli.Firstly,the predominant spoilage bacteria in fresh and wet vermicelli were identified as Bacillus aryabhattai through high-throughput sequencing.Then,the influence of H_(2)O_(2) on the inhibition zone diameter(IZD),the minimum inhibitory concentration(MIC),the minimum bactericidal concentration(MBC)and the growth curve of B.aryabhattai were analyzed through antibacterial activity assays.Simultaneously,the mechanism of antibacterial action experiments was conducted to observe the effects of H_(2)O_(2) on the disruption of cell membrane and cell wall of B.aryabhattai,as well as the leakage of intracellular functional components.The results showed that increasing the concentration of H_(2)O_(2) from 250μg/mL to 1000μg/mL resulted in an 8 mm increased IZD.Additionally,MIC and MBC of H_(2)O_(2) were both 250μg/mL.The growth curve analysis revealed that bacterial growth was completely inhibited within 24 hours when the concentration of H_(2)O_(2) was higher than 250μg/mL.The mechanism of antibacterial action experiments indicated that increasing concentrations of H_(2)O_(2) significantly raised the concentrations of nucleic acids and proteins in the supernatant of the bacterial liquid(P<0.05),while also disrupting the cell wall and membrane structure of B.aryabhattai,leading to the leakage of alkaline phosphatase(AKP)andβ-galactosidase(β-GAL)outside the cells,and it exhibited a concentration-dependent relationship with H_(2)O_(2).Therefore,H_(2)O_(2) at 250μg/mL effectively inhibited the activity of B.aryabhattai in fresh and wet vermicelli.This study provides a theoretical basis and production guidance for extending the shelf life and increasing the market value of fresh and wet vermicelli.