ZOBELL C E, COBET A B
J Bacteriol. 1964 Mar;87(3):710-9. doi: 10.1128/jb.87.3.710-719.1964.
ZoBell, Claude E. (University of California, La Jolla), and Andre B. Cobet. Filament formation by Escherichia coli at increased hydrostatic pressures. J. Bacteriol. 87:710-719. 1964.-The reproduction as well as the growth of Escherichia coli is retarded by hydrostatic pressures ranging from 200 to 500 atm. Reproduction was indicated by an increase in the number of cells determined by plating on EMB Agar as well as by direct microscopic counts. Growth, which is not necessarily synonymous with reproduction, was indicated by increase in dry weight and protein content of the bacterial biomass. At increased pressures, cells of three different strains of E. coli tended to form long filaments. Whereas most normal cells of E. coli that developed at 1 atm were only about 2 mu long, the mean length of those that developed at 475 atm was 2.93 mu for strain R(4), 3.99 mu for strain S, and 5.82 mu for strain B cells. Nearly 90% of the bacterial biomass produced at 475 atm by strain B was found in filaments exceeding 5 mu in length; 74.7 and 16.4% of the biomass produced at 475 atm by strains S and R(4), respectively, occurred in such filaments. Strain R(4) formed fewer and shorter (5 to 35 mu) filaments than did the other two strains, whose filaments ranged in length from 5 to >100 mu. The bacterial biomass produced at all pressures had approximately the same content of protein and nucleic acids. But at increased pressures appreciably more ribonucleic acid (RNA) and proportionately less deoxyribonucleic acid (DNA) was found per unit of biomass. Whereas the RNA content per cell increased with cell length, the amount of DNA was nearly the same in long filaments formed at increased pressure as in cells of normal length formed at 1 atm. The inverse relationship between the concentration of DNA and cell length in all three strains of E. coli suggests that the failure of DNA to replicate at increased pressure may be responsible for a repression of cell division and consequent filament formation.
佐贝尔，克劳德·E.（加利福尼亚大学，拉霍亚分校），以及安德烈·B.科贝特。大肠杆菌在静水压力升高时形成丝状结构。《细菌学杂志》87:710 - 719。1964年。——静水压力在200至500个大气压范围内会抑制大肠杆菌的繁殖和生长。通过在伊红美蓝琼脂平板上接种并计数以及直接显微镜计数来确定细胞数量的增加，以此表明繁殖情况。生长并不一定等同于繁殖，通过细菌生物质的干重和蛋白质含量的增加来表明生长情况。在压力升高时，三种不同菌株的大肠杆菌细胞倾向于形成长丝状结构。在1个大气压下生长的大多数正常大肠杆菌细胞长度仅约2微米，而在475个大气压下生长的细胞，R(4)菌株的平均长度为2.93微米，S菌株为3.99微米，B菌株细胞为5.82微米。在475个大气压下，B菌株产生的细菌生物质中近90%存在于长度超过5微米的丝状结构中；在475个大气压下，S菌株和R(4)菌株分别有74.7%和16.4%的生物质存在于此类丝状结构中。R(4)菌株形成的丝状结构比其他两个菌株少且短（5至35微米），其他两个菌株的丝状结构长度范围为5至大于100微米。在所有压力下产生的细菌生物质中蛋白质和核酸的含量大致相同。但在压力升高时，每单位生物质中发现的核糖核酸（RNA）明显更多，而脱氧核糖核酸（DNA）则相应减少。虽然每个细胞的RNA含量随细胞长度增加，但在压力升高时形成的长丝状结构中的DNA量与在1个大气压下形成的正常长度细胞中的DNA量几乎相同。在所有三种大肠杆菌菌株中，DNA浓度与细胞长度之间的反比关系表明，在压力升高时DNA无法复制可能是细胞分裂受到抑制并进而形成丝状结构的原因。
