ISSN:
1432-072X
Keywords:
Marine bacteria
;
Sulfur metabolism
;
Protein synthesis
;
Pseudomonas halodurans
;
Alteromonas luteoviolaceus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Analysis of the distribution of 35S-sulfate and 14C-glutamate in major biochemical components of the two marine bacteria, Pseudomonas halodurans and Alteromonas luteo-violaceus, was compared with cell density and total cellular protein during exponential growth in batch culture. For both organisms, the sulfur distribution was restricted principally to the low molecular weight organic and protein fractions, which together accounted for over 90% of the total sulfur. Carbon was more widely distributed, with these two fractions containing only 70% of the total label. Growth rate constants calculated from increases in cell numbers, protein, and 35S and 14C in the various fractions indicated nearly balanced growth in A. luteo-violaceus, with constants derived from all biosynthetic parameters agreeing within 5% during the exponential phase. In contrast, protein synthesis and 35S incorporation into residue protein constants were 30% higher than constants derived from cell counts and incorporation of 14C in P. halodurans. Therefore the cellular protein content P. halodurans varied over a two-fold range, with maximum protein per cell in the late exponential phase. A distinct reduction in the rate constants for total protein and 35S incorporation into residue protein foreshadowed entry into the stationary phase more than one generation before other parameters. Incorporation of 35S-sulfate into residue protein paralleled protein synthesis in both bacteria. The weight percent S in protein agreed well with the composition of an “average protein” derived from the literature. Sulfur incorporation into protein may be a useful measurement of marine bacterial protein synthesis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00527064
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