柠檬酸(CA)和电解水(EW)被认为有效地灭活微生物。本研究旨在探讨CA联合EW对气单胞菌的杀菌机理。通过体外代谢组学方法在barramundi(Latescalcarifer)中。这项研究确定了三株气单胞菌细菌的存活种群(菌株1:沙门氏菌气单胞菌菌株A1(皮肤);菌株2:Veronii菌株Til2(肠道),和菌株3:嗜水气单胞菌菌株B11(g)),从单独或与1%CA和EW(游离有效氯(FAC)25mg/L,pH3.23,氧化还原电位(ORP)1015mV)。通过微生物分析研究了杀菌机理,核磁共振(NMR),多元数据分析,和荧光染色分析。结果表明,联合处理可显着降低气单胞菌的数量,达到1.64-1.69logCFU/g,并延长了barramundi鱼片的货架期。此外,联合治疗对细菌的细胞膜完整性有更高的影响。总的来说,在三个菌株中鉴定出36种代谢物。未解离的CA分子可以进入细胞质,导致细胞损伤和抑制代谢途径。EW可导致氧化应激和酸胁迫引起的代谢产品减少。在CA和EW的协同胁迫下,联合治疗组主要代谢产物含量变化明显减少。综合治疗后,有20、31和31种碳水化合物代谢途径,氨基酸代谢,能量代谢发生了很大变化。这些发现表明杀菌物质的杀菌机制可能是通过干扰代谢途径来解释的。指导后处理卫生,并将NMR光谱的适用性扩展到鱼类中的特定腐败生物(SSO)分析。
The citric acid (CA) and electrolysed water (EW) are considered effectively in inactivating microorganisms. The objective of this study was to explore the bactericidal mechanism of CA combined with EW on Aeromonas spp. in
barramundi (Lates calcarifer) by in vitro metabolomics method. This study determined the survival population of three strains of Aeromonas bacteria (strain 1: Aeromonas salmonicida strain A1 (skin); strain 2: A. veronii strain Til2 (gut), and strain 3: A. hydrophila strain B11 (gill)), which were isolated and identified from putrid
barramundi treated alone or in combination with 1 % CA and EW (free available chlorine (FAC) 25 mg/L, pH 3.23, oxidation-reduction potential (ORP) 1015 mV). The bactericidal mechanism was investigated by microbiological analysis, nuclear magnetic resonance (NMR), multivariate data analysis, and fluorescence staining analysis. The results showed that the combined treatment significantly reduced the number of Aeromonas bacteria at 1.64-1.69 log CFU/g and extended the shelf life of
barramundi fillets. In addition, the combined treatment had a higher effect on the cell membrane integrity of the bacteria. In total, 36 metabolites were identified in the three strains. The undissociated molecules of CA can enter the cytoplasm, resulting in cell damage and inhibiting metabolic pathways. EW could lead to the reduction of metabolic products caused by oxidative stress and acid stress. Under the synergistic stress of CA and EW, the changes of main metabolite contents in the combined treatment group were significantly reduced. After combined treatment, there were 20, 31, and 31 pathways in which carbohydrate metabolism, amino acid metabolism, and energy metabolism were changed considerably. These findings indicated that the bactericidal mechanism of the bactericidal substance might be explained by the interference of the metabolic pathway, which guided post-treatment sanitisation and extended the applicability of the NMR spectrum to specific spoilage organisms (SSO) analysis in fish.