کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4370087 | 1616764 | 2006 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effect of environmental stresses on the mean and distribution of individual cell lag times of Escherichia coli O157:H7
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش تغذیه
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
The effect of starvation, heat or acid stress on duration of individual cell lag time (Ï) and standard deviation (SD) of Ï was investigated using Escherichia coli O157:H7. Cells were stressed by exposure to acid (pH 3.5), heat (50 °C), or starvation in either glucose-free mineral medium (MOPS), tryptic soy broth (TSB) or Luria broth (LB). Stressed cells were then diluted into wells of a Bioscreen plate to obtain single cells per well. Replicate time to detection (td) values were obtained using the Bioscreen and used to calculate the Ï and SD. Significant (P â¤Â 0.05) increases in Ï over untreated controls were found for the following treatments: 14 days in acid; 2 h of heating; 3 days starvation in MOPS; and 2 days starvation in either TSB or LB. The largest increase in Ï was > 2-fold from 2.5 to 5.6 h observed with the heat treatment. MOPS starvation was more detrimental to the cells than was acid treatment over the same time period. A significant increase in SD was found with 21 days acid treatment, and 2 days starvation in either TSB or LB. No significant increase in SD was found for MOPS starvation or heat treatment. Lognormal, Gamma, ExtremeValue and Weibull distributions were fitted to the Ï data using BestFit. The results suggest that the Lognormal distribution is suitable for fitting Ï data from either stressed or unstressed cells.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Food Microbiology - Volume 110, Issue 3, 1 August 2006, Pages 278-285
Journal: International Journal of Food Microbiology - Volume 110, Issue 3, 1 August 2006, Pages 278-285
نویسندگان
Yaqin Li, Joseph A. Odumeru, Mansel Griffiths, Robin C. McKellar,