SEMI-ANNUAL PROGRESS REPORT Marine Microbiology Report No. 10 1 July to 31 December 1955 Physiological Activities of Marine Microbes

摘要

Apparatus and methods have been developed for studying the viability, repro¬duction, and physiological activities of bacteria and allied microbes at pressures up to 2000 atm. Most microbes can tolerate for brief periods hydrostatic pressures up to 1000 atm, but prolonged exposure to pressures of 200 to 400 atm results in their gradual death. Microbes’ demonstrated ability to withstand the sudden release of hydrostatic pressures (but not gaseous pressures) indicates that deep-sea bacteria are not injured by the release of pressure resulting from their transposition from the deep-sea floor to the surface in sampling procedures. Several dozen sediment samples have been collected from water depths exceeding 7000 m and found to contain from 10 to 10°viable bacteria per gram vet weight. Some of these deep-sea bacteria appear to be barophilic (capable of growing only at high pres¬sure).