柠檬醛对指状青霉菌丝体膜脂过氧化的影响

探讨柠檬醛对指状青霉菌丝体膜脂过氧化的影响。研究发现，经最小抑菌浓度（minimal inhibitoryconcentration，MIC，2.0 μL/mL）和最小杀菌浓度（minimal fungicidal concentration，MFC，4.0 μL/mL）柠檬醛处理后，指状青霉菌丝体发生扭曲变形且表面出现明显褶皱，表明细胞完整性遭到破坏。不同质量浓度柠檬醛处理指状青霉后，其胞外电导率及K＋泄漏量均显著增加，而总脂质含量降低，说明柠檬醛处理能增加指状青霉细胞膜通透性，导致细胞膜结构遭受破坏。进一步研究发现，MIC、MFC柠檬醛处理促使指状青霉总丙二醛含量、过氧化氢含量和脂氧合酶、过氧化物酶活性升高。本研究结果表明：柠檬醛处理可诱导指状青霉菌丝体发生严重的膜脂过氧化损伤，损伤细胞膜结构，从而抑制指状青霉菌丝体生长。

Citral Inhibits Mycelial Growth of Penicillium digitatum Involving Membrane Peroxidation

The effects of citral on membrane lipid peroxidation of Penicillium digitatum were investigated in this study.After treated with citral at minimal inhibitory concentration (MIC, 2.0 μL/mL) and minimal fungicidal concentration (MFC,4.0 μL/mL), the morphology of P. digitatum hyphae was evidently altered, as indicated by a wrinkled and rough surface,by causing loss of cytoplasm and distortion of mycelia. Extracellular conductivity and the leakage of potassium ions weresignificantly higher after citral treatment compared with the control, which indicated the increase of membrane permeability.Moreover, citral could decrease the total lipid content of P. digitatum cells, indicating the disruption of membrane integrity.Furthermore, the addition of citral (at both MIC and MFC) significantly increased the contents of total malondialdehydeand hydrogen peroxide, and the activities of lipoxygenase and peroxidase. These results indicate that citral inhibits mycelialgrowth of P. digitatum by a membrane damage mechanism involving membrane peroxidation.