Ribosomes exist in large excess over the apparent demand for protein synthesis during carbon starvation in marine Vibrio sp. strain CCUG 15956

Abstract

Carbon starvation induces the development of a starvation-and stress-resistant cell state in marine Vibrio sp. strain S14 (CCUG 15956

Stringent control during carbon starvation of marine Vibrio sp. strain S14: molecular cloning, nucleotide sequence, and deletion of the relA gene

“…However, the functional roles of the reL4-mediated stringent response and ppGpp appear to be restricted to a transition phase at the onset of carbon starvation, and cells that are carbon starved for long periods have very small ppGpp pools. The rate of protein synthesis in such nongrowing cells is very low, yet the cells contain an excess of ribosomes and respond immediately to substrate addition (5,6 (6), indicating that the cells may be primarily affected by energy depletion.…”

“…Antibiotics were used at the following concentrations: ampicillin, 50 ,ug/ml; tetracycline, 12.5 pug/ml; kanamycin, 50 pug/ml for E. coli and 85 jug/ml for Vibrio strains; and streptomycin, 200 tug/ml. Carbon starvation was achieved by growing Vibrio cultures in low-glucose-concentration MMM until growth was arrested because of depletion of glucose (5). Multiple-nutrient starvation was achieved by growing cultures in complex medium, washing them, and resuspending them in artificial seawater as described previously (27).…”

“…The Vibrio strains were grown for one generation in glucose-containing MMM in the presence of [5,6-3H]uridine (50 ,uM; 74 kBq ml-') (Amersham) before the response to SHMT was monitored. Throughout the incubation, 200-,ul samples were added to 2 ml of ice-cold 5% TCA and processed as described previously (5 coli strains fail to grow on AT medium, apparently because of failure to synthesize enough imidazole-glycerol phosphate dehydratase to overcome the inhibition of this enzyme by aminotriazole (51). This provides a positive selection system, which was used to isolate the Vibric relA gene.…”

“…Analysis of ppGpp was done after isocratic elution (1.0 ml min-') with 30 mM KH2PO4-3 mM tetrabu-CARBON STARVATION AND rel GENE IN V/7BRO SP. STRAIN S14 [5,6-3H]uridine as described previously (5). The Vibrio strains were grown for one generation in glucose-containing MMM in the presence of [5,6-3H]uridine (50 ,uM; 74 kBq ml-') (Amersham) before the response to SHMT was monitored.…”

Evaluating rRNA as an indicator of microbial activity in environmental communities: limitations and uses

“…Concentration of rRNA and growth rate are not always simply correlated; therefore, the relationship between rRNA and activity is not likely consistent (Schaechter et al, 1958;Mandelstam and Halvorson, 1960;Flärdh et al, 1992, Kemp et al, 1993Tolker-Nielsen et al, 1997;Binder and Liu, 1998;Lepp and Schmidt, 1998;McKillip et al, 1998;Kerkhof and Kemp, 1999;Morgenroth et al, 2000;Oda et al, 2000;Schmid et al, 2001;Worden and Binder, 2003). 2.…”