Compiling a Molecular Inventory for Mycobacterium bovis BCG at Two Growth Rates: Evidence for Growth Rate-Mediated Regulation of Ribosome Biosynthesis and Lipid Metabolism Export

@article{citeulike:1553882, abstract = {An experimental system of Mycobacterium tuberculosis growth in a carbon-limited chemostat has been established by the use of Mycobacterium bovis BCG as a model organism. For this model, carbon-limited chemostats with low concentrations of glycerol were used to simulate possible growth rates during different stages of tuberculosis. A doubling time of 23 h (D = 0.03 h-1) was adopted to represent cells during the acute phase of infection, whereas a lower dilution rate equivalent to a doubling time of 69 h (D = 0.01 h-1) was used to model mycobacterial persistence. This chemostat model allowed the specific response of the mycobacterial cell to carbon limitation at different growth rates to be elucidated. The macromolecular (RNA, DNA, carbohydrate, and lipid) and elemental (C, H, and N) compositions of the biomass were determined for steady-state cultures, revealing that carbohydrates and lipids comprised more than half of the dry mass of the BCG cell, with only a quarter of the dry weight consisting of protein and RNA. Consistent with studies of other bacteria, the specific growth rate impacts on the macromolecular content of BCG and the proportions of lipid, RNA, and protein increased significantly with the growth rate. The correlation of RNA content with the growth rate indicates that ribosome production in carbon-limited M. bovis BCG cells is subject to growth rate-dependent control. The results also clearly show that the proportion of lipids in the mycobacterial cell is very sensitive to changes in the growth rate, probably reflecting changes in the amounts of storage lipids. Finally, this study demonstrates the utility of the chemostat model of mycobacterial growth for functional genomic, physiology, and systems biology studies. 10.1128/JB.187.5.1677-1684.2005}, author = {Beste, D. J. V. and Peters, J. and Hooper, T. and Avignone-Rossa, C. and Bushell, M. E. and Mcfadden, J.}, citeulike-article-id = {1553882}, citeulike-linkout-0 = {http://dx.doi.org/10.1128/JB.187.5.1677-1684.2005}, citeulike-linkout-1 = {http://jb.asm.org/cgi/content/abstract/187/5/1677}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/15716438}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=15716438}, day = {1}, doi = {10.1128/JB.187.5.1677-1684.2005}, journal = {J. Bacteriol.}, keywords = {chemostat, fba, metabolic-models, tb}, month = {March}, number = {5}, pages = {1677--1684}, posted-at = {2008-07-18 05:22:05}, priority = {2}, title = {Compiling a Molecular Inventory for Mycobacterium bovis BCG at Two Growth Rates: Evidence for Growth Rate-Mediated Regulation of Ribosome Biosynthesis and Lipid Metabolism}, url = {http://dx.doi.org/10.1128/JB.187.5.1677-1684.2005}, volume = {187}, year = {2005} }

TY - JOUR ID - citeulike:1553882 L3 - citeulike-article-id:1553882 N2 - An experimental system of Mycobacterium tuberculosis growth in a carbon-limited chemostat has been established by the use of Mycobacterium bovis BCG as a model organism. For this model, carbon-limited chemostats with low concentrations of glycerol were used to simulate possible growth rates during different stages of tuberculosis. A doubling time of 23 h (D = 0.03 h-1) was adopted to represent cells during the acute phase of infection, whereas a lower dilution rate equivalent to a doubling time of 69 h (D = 0.01 h-1) was used to model mycobacterial persistence. This chemostat model allowed the specific response of the mycobacterial cell to carbon limitation at different growth rates to be elucidated. The macromolecular (RNA, DNA, carbohydrate, and lipid) and elemental (C, H, and N) compositions of the biomass were determined for steady-state cultures, revealing that carbohydrates and lipids comprised more than half of the dry mass of the BCG cell, with only a quarter of the dry weight consisting of protein and RNA. Consistent with studies of other bacteria, the specific growth rate impacts on the macromolecular content of BCG and the proportions of lipid, RNA, and protein increased significantly with the growth rate. The correlation of RNA content with the growth rate indicates that ribosome production in carbon-limited M. bovis BCG cells is subject to growth rate-dependent control. The results also clearly show that the proportion of lipids in the mycobacterial cell is very sensitive to changes in the growth rate, probably reflecting changes in the amounts of storage lipids. Finally, this study demonstrates the utility of the chemostat model of mycobacterial growth for functional genomic, physiology, and systems biology studies. 10.1128/JB.187.5.1677-1684.2005 IS - 5 JF - J. Bacteriol. EP - 1684 TI - Compiling a Molecular Inventory for Mycobacterium bovis BCG at Two Growth Rates: Evidence for Growth Rate-Mediated Regulation of Ribosome Biosynthesis and Lipid Metabolism VL - 187 SP - 1677 KW - chemostat KW - fba KW - metabolic-models KW - tb AU - Beste, DJV AU - Peters, J AU - Hooper, T AU - Avignone-Rossa, C AU - Bushell, ME AU - Mcfadden, J PY - 2005/03/01/ UR - http://dx.doi.org/10.1128/JB.187.5.1677-1684.2005 ER -