Dean C R, Ward O P
Department of Biology, University of Waterloo, Ontario, Canada.
Appl Environ Microbiol. 1991 Jul;57(7):1893-8. doi: 10.1128/aem.57.7.1893-1898.1991.
Escherichia coli cells were found to be sensitive to lysis by the supernatants of a variety of protease-positive Bacillus species when treated at 45 degrees C but not when treated at 37 degrees C. Different E. coli strains manifested different lysis sensitivities when treated at 45 degrees C. When the lysis rates of E. coli cells at various stages of growth were investigated, post-exponential-phase cells were shown to be most sensitive to lysis. The lysis rate was inversely related to cell viability, and susceptibility appeared to be at least partly due to lysis of dead E. coli cells. A close relation was observed between levels of lysis activity and proteolytic activity. A Bacillus subtilis mutant lacking alkaline and neutral protease activity failed to lyse E. coli cells. It was concluded that Bacillus proteases played a major role in the observed E. coli lysis.
研究发现，当在45摄氏度处理时，多种蛋白酶阳性芽孢杆菌属物种的上清液可使大肠杆菌细胞发生裂解，但在37摄氏度处理时则不会。不同的大肠杆菌菌株在45摄氏度处理时表现出不同的裂解敏感性。当研究大肠杆菌细胞在不同生长阶段的裂解率时，发现指数生长期后的细胞对裂解最为敏感。裂解率与细胞活力呈负相关，敏感性似乎至少部分归因于死亡大肠杆菌细胞的裂解。观察到裂解活性水平与蛋白水解活性之间存在密切关系。缺乏碱性和中性蛋白酶活性的枯草芽孢杆菌突变体无法裂解大肠杆菌细胞。得出的结论是，芽孢杆菌蛋白酶在观察到的大肠杆菌裂解中起主要作用。
