γ射线联合肉桂精油对腐败希瓦氏菌的抑制机制

Antimicrobial Mechanism of Combination of γ Irradiation and Cinnamon Essential Oil against Shewanella putrefaciens

研究γ射线辐照和肉桂精油联合对腐败希瓦氏菌(Shewanella putrefaciens)的抑制效果,分析联合作用对S.putrefaciens的抑制机制。结果表明:辐照D_(10)(菌落总数降低到原始数量的10%所需要的辐照剂量)随着肉桂精油质量浓度的增加而减少,S.putrefaciens对辐照的相对敏感度随肉桂精油质量浓度的增加而增加。辐照和肉桂精油联合对S.putrefaciens具有较好的抑制作用,其对S.putrefaciens细胞形态、胞内外ATP、胞内p H值、膜蛋白以及膜脂肪酸等均具有显著破坏作用。联合作用处理S.putrefaciens的膜蛋白40 k D亚基减少,18 k D亚基增加,且使S.putrefaciens主要膜脂肪酸C_(14∶0)、C_(16∶0)、C_(16∶1)、C_(17∶1)、C_(18∶1)显著减少(P<0.05),其机理可能在于γ射线辐照增加了肉桂精油对S.putrefaciens细胞膜的破坏,从而导致其死亡。

The combined antibacterial effect ofγirradiation and cinnamon essential oil(CEO)against Shewanella putrefaciens was evaluated and the underlying mechanism was investigated.The irradiation dose required to reduce total colony number to10%of the initial level(D10)was reduced and the relative irradiation sensitivity was increased with increased concentration of CEO.The combination ofγirradiation and CEO was more effective in inhibiting the growth of S.putrefaciens than each alone.The combination treatment exhibited an obvious negative effect on cell morphology,intracellular ATP and pH,membrane proteins and fatty acids in S.putrefaciens.The combination resulted in a reduction of40kD subunits and an increase of18kD subunits in membrane proteins,as well as a significant reduction of C14:0,C16:0,C16:1,C17:1,and C18:1in membrane lipids(P<0.05).The mechanism for the synergism was due to the potential ofγirradiation to increase the destructive effect of CEO on the cell membrane of S.putrefaciens thus causing its death.