THE ENDOGENOUS METABOLISM OF ANAEROBIC BACTERIA
Final technical rept. Apr 1966-Mar 1967
HULL UNIV (UNITED KINGDOM) DEPT OF BIOCHEMISTRY
Pagination or Media Count:
The continuation of an investigation of the endogenous metabolism and survival of non-spore-forming anaerobic bacteria under conditions of starvation is reported. The two glucose-fermenting organisms of the genus Zymomonas, Zymomonas anaerobia and Zymomonas mobilis, differ in that RNA is lost very much more rapidly from Z. mobilis than from Z. anaerobia, although the survival patterns are very similar. Both organisms are resistant to prolonged starvation. Magnesium ions suppress RNA degradation but do not confer protection against death. The remarkably constant protein content of Z. anaerobia does not seem to mask any kind of turnover or preferential degradation and resynthesis of specific proteins. The protein of Peptococcus prevotii is also remarkably stable and the observed release of ammonia is probably derived from deamination of nucleotide bases. The endogenous metabolism of this organism continues in the presence of exogenous glucose. To study the energetics of starvation the ATP contents of Z. anaerobia and P. prevotii have been measured by the firefly luciferase technique. In both cases the ATP content falls rapidly within the initial few hours and then levels out at a small value it is clearly not related directly to the viability. The capacity of P. prevotii to synthesize ATP during starvation was therefore tested at intervals by adding pulses of suitable energy-yielding substrates such as serine, threonine and pyruvate. The ability to produce ATP on addition of serine is virtually abolished after 42 hours of starvation.