Song Wei, Xin Jiaying, Yu Chong, Xia Chungu, Pan Yu
Key Laboratory for Food Science and Engineering, Harbin University of Commerce, Harbin, China.
State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China.
Front Microbiol. 2023 Feb 10;14:1135308. doi: 10.3389/fmicb.2023.1135308. eCollection 2023.
Ferulic acid (FA) is a natural antibacterial agent rich in plants, FA has excellent antioxidant and antibacterial properties. However, because of its short alkane chain and large polarity, FA is difficult to penetrate the soluble lipid bilayer in the biofilm to enter the cell to play an inhibitory role, limiting its biological activity. To improve the antibacterial activity of FA, with the catalytic condition of Novozym 435, four alkyl ferulic acid esters (FCs) with different alkyl chain lengths were obtained by fatty alcohols (including 1-propanol (C3), 1-hexanol (C6), nonanol (C9), and lauryl alcohol (C12)) modification. The effect of FCs on was determined by Minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), Growth curves, alkaline phosphatase (AKP) activity, crystal violet method, scanning electron microscopy (SEM), membrane potential, PI, cell contents leakage. Results showed that the antibacterial activity of FCs increased after esterification, and the antibacterial activity significantly increased and then decreased with the extension of the alkyl chain of the FCs. Hexyl ferulate (FC6) showed the best antibacterial activities against and (MIC for was 0.5 mg/ml, MIC for was 0.4 mg/ml). And Propyl ferulate (FC3) and FC6 showed the best antibacterial activities S. aureus and (MIC for was 0.4 mg/ml, The MIC of was 1.1 mg/ml). In addition, the growth, AKP activity, bacterial biofilm, bacterial cell morphology, membrane potential and cell contents leakage of after different FCs were investigated, which found that FCs could damage the cell wall of and showed different effects on the cell biofilm. FC6 showed the best inhibition on the biofilm formation of cells, which caused the surface of cells to be rough and wrinkled. Some cells showed aggregation and adhesion, even rupture. The membrane hyperpolarization was obvious, which appeared as holes, leading to cell contents leakage (protein and nucleic acid). All these results concluded that the antibacterial activities FCs against foodborne pathogens depended on different fatty alcohol esterification of FA. FC6 showed the best inhibition on due to its effect on cell walls and biofilms and the leak of the cell contents. This study provides more practical methods and a theoretical basis for giving full play to the bacteriostatic effect of plant FA.
阿魏酸（FA）是一种富含于植物中的天然抗菌剂，具有出色的抗氧化和抗菌性能。然而，由于其烷链短且极性大，FA难以穿透生物膜中的可溶性脂质双层进入细胞发挥抑制作用，限制了其生物活性。为提高FA的抗菌活性，在诺维信435的催化条件下，通过脂肪醇（包括1 - 丙醇（C3）、1 - 己醇（C6）、壬醇（C9）和月桂醇（C12））修饰获得了四种不同烷基链长度的阿魏酸烷基酯（FCs）。通过最低抑菌浓度（MIC）、最低杀菌浓度（MBC）、生长曲线、碱性磷酸酶（AKP）活性、结晶紫法、扫描电子显微镜（SEM）、膜电位、碘化丙啶（PI）、细胞内容物泄漏等方法测定了FCs对[具体对象未给出]的影响。结果表明，酯化后FCs的抗菌活性增强，且随着FCs烷基链的延长，抗菌活性先显著增加后降低。己基阿魏酸酯（FC6）对[具体对象未给出]表现出最佳抗菌活性（对[具体对象未给出]的MIC为0.5mg/ml，对[具体对象未给出]的MIC为0.4mg/ml）。丙基阿魏酸酯（FC3）和FC6对金黄色葡萄球菌和[具体对象未给出]表现出最佳抗菌活性（对[具体对象未给出]的MIC为0.4mg/ml，对[具体对象未给出]的MIC为1.1mg/ml）。此外，研究了不同FCs作用后[具体对象未给出]的生长、AKP活性、细菌生物膜、细菌细胞形态、膜电位和细胞内容物泄漏情况，发现FCs可破坏[具体对象未给出]的细胞壁，并对[具体对象未给出]细胞生物膜有不同影响。FC6对[具体对象未给出]细胞生物膜形成的抑制作用最佳，导致[具体对象未给出]细胞表面粗糙起皱。一些[具体对象未给出]细胞出现聚集、黏附，甚至破裂。膜超极化明显，呈现出孔洞，导致细胞内容物泄漏（蛋白质和核酸）。所有这些结果表明，FCs对食源性病原体的抗菌活性取决于FA的不同脂肪醇酯化。FC6由于其对[具体对象未给出]细胞壁和生物膜的作用以及细胞内容物的泄漏，对[具体对象未给出]表现出最佳抑制作用。本研究为充分发挥植物FA的抑菌作用提供了更具实用性的方法和理论依据。
