GROWTH AND SURVIVAL OF CAMPYLOBACTER-FETUS SUBSP JEJUNI AS A FUNCTION OF TEMPERATURE AND PH
GROWTH AND SURVIVAL OF CAMPYLOBACTER-FETUS SUBSP JEJUNI AS A FUNCTION OF TEMPERATURE AND PH
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DOI：
10.4315/0362-028x-44.8.596
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发表时间：
1981-01-01
影响因子：
2
通讯作者：
ROMAN, DJ
中科院分区：
文献类型：
--
作者：
DOYLE, MP;ROMAN, DJ
本研究的目的是确定温度和pH值对C.胎儿亚种jejuni肠to grow生长and survive生存. 3株C.胎儿亚种空肠在30 ℃时能正常生长。或低于47 ℃。C及以上。生长的最适温度范围为42 ℃ ~ 48 ℃。45 ℃。3种菌株中只有1种FRI-CF 8可以在pH 4.9下生长，没有一种可以在pH 4.7下生长。生长的最适pH在6.5-7.5的范围内;所有菌株在pH 5.5-8.0生长良好。在pH3.0 -4.5时，细胞死亡率是温度依赖性的。在相同pH条件下，C.胎儿亚种空肠在42 ℃时死亡最快。C，在25 ℃时不太迅速。在4.0 ℃时，速率最慢。C.例如，在pH4.5，当在42 ℃温育时，在8小时内细胞减少3log 10。但在4 ℃孵育时需要4天。C.在25度。C和pH 4.5时，细胞以中等速率失活。Rates. 5株C.胎儿亚种空肠在48 °测定，50 °，53.degree. 55度。在脱脂牛奶中加热。在48度。C，D-值范围为7.2-12.8分钟，而在55 ℃时，巴氏消毒牛奶的时间和温度应足以使牛奶中含有大量的活的C.胎儿亚种空肠。
The objective of this study was to determine what effect temperature and pH have on the ability of C. fetus ssp. jejuni to grow and survive. None of 3 strains of C. fetus ssp. jejuni could grow at 30.degree. C and below or at 47.degree. C and above. The optimum temperature for growth was in the range of 42.degree.-45.degree.C. Only 1 of 3 strains, FRI-CF8, could grow at pH 4.9 and none could grow at pH 4.7. The optimum pH for growth was in the range of 6.5-7.5; all strains grew well at pH 5.5-8.0. Rate of cell death at pH 3.0-4.5 was temperature-dependent. At comparable pH, cells of C. fetus ssp. jejuni died most rapidly at 42.degree. C, less rapidly at 25.degree. C and at the slowest rate at 4.degree. C. For example, at pH 4.5, a 3 log10 decrease of cells occurred within 8 h when incubated at 42.degree. C but took 4 days when incubated at 4.degree. C. At 25.degree. C and pH 4.5, cells were inactivated at an intermediate rate. Rates. of thermal inactivation of 5 strains of C. fetus ssp. jejuni were determined at 48.degree., 50.degree., 53.degree. and 55.degree. C in a skim milk heating menstruum. At 48.degree. C, D-values ranged from 7.2-12.8 min while at 55.degree. C they ranged from 0.74-1.00 min. The times and temperatures used to pasteurize milk should be sufficient to free milk of even unusually large numbers of viable cells of C. fetus ssp. jejuni.