Kobayashi Fumiyuki, Odake Sachiko
Faculty of Applied Life Science, Nippon Veterinary and Life Science University, Musashino, Tokyo Japan.
J Food Sci Technol. 2020 Feb;57(2):588-594. doi: 10.1007/s13197-019-04090-0. Epub 2019 Sep 10.
Temperature-dependency on cell membrane injury and inactivation of by low-pressure carbon dioxide microbubbles (MBCO) was investigated. The number of surviving cells after MBCO treatment detected with yeast and mould agar (YMA, an optimum agar) was higher than that with YMA adding 2.5 g/L sodium chloride and yeast nitrogen base agar (a minimum agar). However, the decrease of the surviving number by thermal treatment was not changed among above agars used. The fluorescence polarization (FP), which indicated the phase transition of the membrane of cells treated with MBCO increased with increasing temperature. The activity of the alkaline phosphatase (AP), a periplasmic enzyme, in cells after MBCO and thermal treatments increased with the FP but was reduced by further increasing temperature. The FP and AP activities after MBCO treatment increased at a temperature lower than the temperature of the thermal treatment. In addition, intracellular pH of decreased by the MBCO treatment at lower temperature with increasing pressure. Therefore, it was revealed that phase transition of the cell membrane and inactivation of was caused by MBCO treatment at lower temperature than thermal treatment and that the effect was induced by the dissolved CO and increased with increasing pressure.
研究了低压二氧化碳微泡（MBCO）对细胞膜损伤和细胞失活的温度依赖性。用酵母和霉菌琼脂（YMA，一种最佳琼脂）检测MBCO处理后存活的细胞数量，高于添加2.5 g/L氯化钠的YMA和酵母氮基琼脂（一种基本琼脂）。然而，上述琼脂在热处理后存活数量的减少没有变化。荧光偏振（FP）表明，经MBCO处理的细胞的膜相变随温度升高而增加。经MBCO和热处理后，细胞周质酶碱性磷酸酶（AP）的活性随FP增加，但进一步升高温度则降低。MBCO处理后的FP和AP活性在低于热处理温度时增加。此外，在较低温度下，随着压力增加，MBCO处理会使细胞内pH值降低。因此，研究表明，细胞膜的相变和细胞失活是由低于热处理温度的MBCO处理引起的，并且这种效应是由溶解的CO诱导的，并且随着压力增加而增强。
