Long-Term Starvation Survival of Rod and Spherical Cells of Arthrobacter crystallopoietes

Abstract

Spherical and rod-shaped cells of Arthrobacter crystallopoietes , harvested during exponential growth, were subjected to total starvation for periods of time as long as 80 days. Viability measurements were made by plate count and slide culture procedures. Both cell forms remained 100% viable for 30 days. Thereafter, viability of rods and spheres decreased equally at a slow rate. After 60 days of starvation, more than 65% of both cell forms were viable. No significant cell lysis occurred as evidenced by microscopic examination, the small amount of 260-nm absorbing material found in the starvation buffer, and stability of radioactively labeled deoxyribonucleic acid in the cells. Endogenous respiration decreased 80-fold during the first 2 days of starvation, accompanied by a 30% decrease in dry weight of the cells. Thereafter, cellular carbon was oxidized to CO 2 at the constant level of 0.03%/hr over the remaining 78-day starvation period.