Martínez-Cuesta M C, Peláez C, Juárez M, Requena T
Departamento de Ciencia y Tecnología de Productos Lácteos, Instituto del Frío (C.S.I.C.), Ciudad Universitaria, Madrid, Spain.
Int J Food Microbiol. 1997 Sep 16;38(2-3):125-31. doi: 10.1016/s0168-1605(97)00099-8.
Autolytic properties of Lactococcus lactis subsp. lactis IFPL359, its Lac Prt derivative Lc. lactis Tl and Lactobacillus casei subsp. casei IFPL731, used as starter and adjunct starter in goat's milk cheese making, have been studied. The lytic effect of a bacteriocin produced by a lactic acid bacterium isolated from raw goat's milk has also been analyzed. Lactococcal cells resuspended in phosphate buffer showed a peak of autolysis when they were harvested in the early growth phase. A more stable autolytic pattern through the exponential growth was obtained for Lb. casei IFPL731. Optimal autolysis was found in 0.1 M sodium phosphate buffer during incubation at 40 degrees C for Lb. casei IFPL731 and at 35 degrees C for the lactococci. Thermoinduction of cell lysis was not obtained in any of the cases under the conditions studied. Lytic effect of the crude bacteriocin assayed was strongest against Lc. lactis Tl. Lysis response to the bacteriocin seemed to be strain-dependent and related to growth conditions.
已对乳酸乳球菌乳亚种IFPL359、其Lac Prt衍生物乳酸乳球菌Tl以及干酪乳杆菌干酪亚种IFPL731（用作山羊奶酪制作的发酵剂和辅助发酵剂）的自溶特性进行了研究。还分析了从生山羊奶中分离出的一种乳酸菌产生的细菌素的溶菌作用。重悬于磷酸盐缓冲液中的乳球菌细胞在生长早期收获时显示出自溶高峰。对于干酪乳杆菌IFPL731，在指数生长期获得了更稳定的自溶模式。干酪乳杆菌IFPL731在40℃孵育期间以及乳球菌在35℃孵育期间，在0.1M磷酸钠缓冲液中发现了最佳自溶。在所研究的条件下，任何情况下均未获得细胞裂解的热诱导。所测定的粗细菌素的溶菌作用对乳酸乳球菌Tl最强。对细菌素的裂解反应似乎取决于菌株并与生长条件有关。
