Starvation-survival patterns of sixteen freshly isolated open-ocean bacteria

Abstract

Sixteen marine isolates from a NORPAX cruise, which were transferred once on medium after initial isolation, survived nutrient deprivation for at least 8 months (longest period test). All but one isolate remained cellularly intact, although their sizes and shapes changed greatly, and all became smaller, decreasing in size from 40 to 79%. Three starvation-survival patterns were demonstrated, namely (i) an initial increase in viable cells followed by a decrease until a constant number was reached, (ii) an increase in viable cells until a constant number was reached, and (iii) a decrease in viable cells until a constant number was reached. One isolate from each starvation-survival pattern was starved for 8 months and then was tested in comparison with 4-month-starved Ant-300 for [C]glutamic acid uptake, respiration, and incorporation. The response to glutamic acid was rapid and linear in each case. The data indicate that the starvation-survival of Ant-300 is not an anomalous situation and that open ocean bacteria can withstand nutrient deprivation for long periods of time and still retain the capacity for active metabolism, if the nutrients become available.