Alternate pressurization–depressurization effects on growth and net protein, RNA and DNA synthesis by Escherichia coli and Vibrio marinus

Abstract

The effects on growth and net protein, ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) synthesis of alternately pressurizing and depressurizing exponentially growing cells of Escherichia coli B/r and Vibrio marinus MP-1 between 1 atm and 544 atm of hydrostatic pressure were studied. The application of 544 atm to these 1 atm exponentially growing cultures caused an almost immediate cessation or lowering in the rates of cell division, absorbance changes, and net protein and RNA synthesis. The cells of E. coli B/r, however, in some manner adapted to 544 atm, since cell division, absorbance, and synthesis of protein and RNA, within minutes, resumed exponential increases but at much lower rates. V. marinus MP-1 did not display this pressure adaption upon the first application of 544 atm. Upon pressure release both cultures resumed the 1-atm exponential increases with respect to cell division and absorbance, and net protein and RNA synthesis. A second application of 544 atm, however, had a less drastic influence on cell division and the rates of increase of absorbance and net protein and RNA synthesis. Both cultures immediately shifted to lower synthetic rates. There was no immediate effect upon DNA synthesis in these two bacteria upon application of 544 atm, but this synthetic process slowed and ceased with time. The data indicate a reversible sensitivity to 544 atm in the order protein > RNA > DNA synthesis and that the cells can in some fashion adapt to pressure resistance.