Graduate School of Agricultural Science, Tohoku Univ., 1-1 Tsutsumidori Amamiyamachi, Aoba-ku, Sendai, Miyagi 981-8555, Japan.
J Food Sci. 2011 Jan-Feb;76(1):M47-53. doi: 10.1111/j.1750-3841.2010.01927.x. Epub 2010 Dec 6.
Inactivation of E. coli by high hydrostatic pressure (250 to 400 MPa) with salts was investigated based on kinetic analysis. At concentrations from 0.074 to 0.145 M and from 0.240 to 0.290 M, both the absolute activation volumes and the preexponential factors were similar in KCl, NaCl, and LiCl solutions, suggesting that pressure inactivation is not salt-specific. On the other hand, in the intermediate salt-concentration range of 0.145 to 0.240 M, inactivation kinetics in the presence of the Na(+) and K(+) differed significantly from those in the presence of Li(+) (P < 0.05). In this concentration range, effect of salt stress and osmotic stress differed significantly from those in concentrations below 0.145 M or above 0.240 M. The cellular response to pressure varies with salt type and salt concentration. These novel findings provide important clues to distinguish between salt stress and osmotic stress in the inactivation of E. coli.
基于动力学分析，研究了高压（250 至 400 MPa）与盐共同作用对大肠杆菌的灭活作用。在浓度为 0.074 至 0.145 M 和 0.240 至 0.290 M 的范围内，KCl、NaCl 和 LiCl 溶液中的绝对活化体积和指数前因子均相似，表明压力灭活作用并非特定于盐。另一方面，在中间盐浓度范围 0.145 至 0.240 M 内，存在 Na(+)和 K(+)时的失活动力学与存在 Li(+)时显著不同（P < 0.05）。在该浓度范围内，盐胁迫和渗透胁迫的影响与浓度低于 0.145 M 或高于 0.240 M 时显著不同。细胞对压力的反应随盐的类型和浓度而变化。这些新发现为区分大肠杆菌失活过程中的盐胁迫和渗透胁迫提供了重要线索。
