Effect of gamma radiation and oregano essential oil on murein and ATP concentration of Escherichia coli O157:H7

被引:35
作者
Caillet, S
Shareck, F
Lacroix, M
机构
[1] Univ Quebec, Inst Armand Frappier, Canadian Irradiat Ctr, Laval, PQ H7V 1B7, Canada
[2] Univ Quebec, Inst Armand Frappier, Res Lab Sci Appl Food, Laval, PQ H7V 1B7, Canada
[3] Univ Quebec, Inst Armand Frappier, Inst Natl Rech Sci, Laval, PQ H7V 1B7, Canada
关键词
D O I
10.4315/0362-028X-68.12.2571
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
This study was carried out to evaluate the effects of gamma radiation alone or in combination with oregano essential oil on the murein composition of Escherichia coli O15:H7 and on the intracellular and extracellular concentrations of ATP. The bacterial strain was treated with three radiation doses: 0.4 kGy to induce cell damage, 1.1 kGy to obtain a viable but non-culturable state, and 1.3 kGy to cause cell death. Oregano essential oil was used at 0.006 and 0.025% (wt/vol), which is the MIC. All treatments had a significant effect (P <= 0.05) on the murein composition, although some muropeptides did not seem to be affected by the treatment. Each treatment had a different effect on the relative percentage and number of muropeptides. There was a significant correlation (P :5 0.05) between the decrease in intracellular ATP and the increase in extracellular ATP following treatment of the cells with oregano oil. The reduction of intracellular ATP was even more important when oregano oil was combined with irradiation, but irradiation alone at a high dose (<= 1.1 kGy) significantly decreased (P <= 0.05) the internal ATP without affecting the external ATP Transmission electron microscopic examination revealed that oregano oil and irradiation have an effect on cell wall structure.
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页码:2571 / 2579
页数:9
相关论文
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[31]  
Urbain W.M., 1986, Food irradiation