Protein content in N-limited & P-limited culture in low & high dilution rates

Range N-limited low D 55±5% high D 55±3%: P-limited low D 65±8% high D 60±3% %
Organism Bacteria Bacillus subtilis
Reference Dauner M, Storni T, Sauer U (2001) Bacillus subtilis metabolism and energetics in carbon-limited and excess-carbon chemostat culture. J Bacteriol 183: 7308–7317 p.7311 right column 2nd paragraphPubMed ID11717290
Method p.7309 left column 2nd paragraph:"The primary focus of this work was to quantify the magnitude of energy dissipation via overflow metabolism, metabolic shifts, and futile enzyme cycling in C-limited and excess-C Bacillus subtilis chemostat cultures, by using isotopomer-balancing (ref 9) and [U-13C6]glucose-labeling experiments (ref 55). Thus, for the first time [investigators] report here intracellular carbon flux distributions in N- and P-limited B. subtilis."
Comments p.7311 right column 2nd paragraph:"Biomass composition: To obtain accurate information on biomass precursor requirements for subsequent metabolic flux analysis, [investigators] determined the relative contents of protein, RNA, and glycogen in [their] cultures. While glycogen was negligible under all conditions, the protein content was 55% ± 5% and 55% ± 3% in the N-limited culture and 65% ± 8% and 60% ± 3% in the P-limited culture at low and high D, respectively. The RNA contents of 6% ± 1% and 9% ± 1% in N-limited cultures and 4% ± 1% and 9% ± 1% in P-limited cultures at low and high D values, respectively, were low when compared to those in C-limited cultures (ref 10). The elemental biomass compositions that were calculated from these macromolecular biomass data agreed well with data from experimental CHN analysis (Table 2), thus validating the results. The high protein content of the slow-growing, P-limited culture correlates with its high nitrogen content. Similarly, the low protein content of the fast-growing, N-limited culture correlates with its low nitrogen content."
Entered by Uri M
ID 111950