Abstract:
:Mycobacterium tuberculosis can persist for many years within host lung tissue without causing clinical disease. Little is known about the state in which the bacilli survive, although it is frequently referred to as dormancy. Some evidence suggests that cells survive in nutrient-deprived stationary phase. Therefore, we are studying stationary-phase survival of Mycobacterium smegmatis as a model for mycobacterial persistence. M. smegmatis cultures could survive 650 days of either carbon, nitrogen, or phosphorus starvation. In carbon-limited medium, cells entered stationary phase before the carbon source (glycerol) had been completely depleted and glycerol uptake from the medium continued during the early stages of stationary phase. These results suggest that the cells are able to sense when the glycerol is approaching limiting concentrations and initiate a shutdown into stationary phase, which involves the uptake of the remaining glycerol from the medium. During early stationary phase, cells underwent reductive cell division and became more resistant to osmotic and acid stress and pool mRNA stabilized. Stationary-phase cells were also more resistant to oxidative stress, but this resistance was induced during late exponential phase in a cell-density-dependent manner. Upon recovery in fresh medium, stationary-phase cultures showed an immediate increase in protein synthesis irrespective of culture age. Colony morphology variants accumulated in stationary-phase cultures. A flat colony variant was seen in 75% of all long-term-stationary-phase cultures and frequently took over the whole population. Cryo scanning electron microscopy showed that the colony organization was different in flat colony strains, flat colonies appearing less well organized than wild-type colonies. Competition experiments with an exponential-phase-adapted wild-type strain showed that the flat strain had a competitive advantage in stationary phase, as well a providing evidence that growth and cell division occur in stationary-phase cultures of M. smegmatis. These results argue against stationary-phase M. smegmatis cultures entering a quiescent state akin to dormancy but support the idea that they are a dynamic population of cells.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Smeulders MJ,Keer J,Speight RA,Williams HDdoi
10.1128/JB.181.1.270-283.1999subject
Has Abstractpub_date
1999-01-01 00:00:00pages
270-83issue
1eissn
0021-9193issn
1098-5530journal_volume
181pub_type
杂志文章abstract::Enzymological studies were done to characterize the allosteric control of 3-deoxy-d-arabino-heptulosonate 7-phosphate (DAHP) synthetase in three species of Clostridium. Allosteric control was identified as feedback inhibition by phenylalanine and was qualitatively similar for the DAHP synthetases of C. butyricum, C. a...
journal_title:Journal of bacteriology
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doi:10.1128/JB.111.3.641-648.1972
更新日期:1972-09-01 00:00:00
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journal_title:Journal of bacteriology
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doi:10.1128/jb.170.6.2742-2748.1988
更新日期:1988-06-01 00:00:00
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journal_title:Journal of bacteriology
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doi:10.1128/jb.177.12.3465-3471.1995
更新日期:1995-06-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
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更新日期:2007-04-01 00:00:00
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journal_title:Journal of bacteriology
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doi:10.1128/JB.187.24.8520-8525.2005
更新日期:2005-12-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.17.5549-5559.1992
更新日期:1992-09-01 00:00:00
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journal_title:Journal of bacteriology
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doi:10.1128/JB.02398-14
更新日期:2015-03-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.111.2.474-480.1972
更新日期:1972-08-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.89.1.23-27.1965
更新日期:1965-01-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01121-07
更新日期:2007-12-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.18.5624-5630.1991
更新日期:1991-09-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.109.2.811-819.1972
更新日期:1972-02-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.98.1.131-142.1969
更新日期:1969-04-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.136.2.723-729.1978
更新日期:1978-11-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.22.7111-7117.1997
更新日期:1997-11-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.23.7360-7368.1997
更新日期:1997-12-01 00:00:00
abstract::For the transformation of the yeast species Kluyveromyces fragilis, we have constructed a vector containing a bacterial kanamycin resistance (Kmr) gene, the TRP1 gene of Saccharomyces cerevisiae, and an autonomously replicating sequence of Kluyveromyces lactis called KARS2 . By utilizing the method based on treatment ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.158.3.1165-1167.1984
更新日期:1984-06-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.4.1141-1145.1996
更新日期:1996-02-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.19.6082-6087.1994
更新日期:1994-10-01 00:00:00
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pub_type: 杂志文章
doi:10.1128/jb.184.3.706-717.2002
更新日期:2002-02-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.17.5448-5457.1997
更新日期:1997-09-01 00:00:00
abstract::Under anaerobic conditions, Klebsiella pneumoniae reduced nitrite (NO2-), yielding nitrous oxide (N2O) and ammonium ions (NH4+) as products. Nitrous oxide formation accounted for about 5% of the total NO2- reduced, and NH4+ production accounted for the remainder. Glucose and pyruvate were the electron donors for NO2- ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.155.2.454-458.1983
更新日期:1983-08-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
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更新日期:2008-05-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
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更新日期:2003-02-01 00:00:00
abstract::In wild-type Escherichia coli the activity of the maltose transport system is dependent on a periplasmic maltose-binding protein. It has been possible, however, to isolate mutants in which transport activity is mediated by the membrane components of the system and is no longer dependent on the periplasmic binding prot...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.165.3.918-922.1986
更新日期:1986-03-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.165.1.334-335.1986
更新日期:1986-01-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
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更新日期:2018-03-12 00:00:00
abstract::Ethanolamine (EA) metabolism is a trait associated with enteric pathogens, including enterohemorrhagic Escherichia coli O157:H7 (EHEC). EHEC causes severe bloody diarrhea and hemolytic uremic syndrome. EHEC encodes the ethanolamine utilization (eut) operon that allows EHEC to metabolize EA and gain a competitive advan...
journal_title:Journal of bacteriology
pub_type: 杂志文章
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更新日期:2013-11-01 00:00:00
abstract::After frog auricles have been in contact with a suspension of bacteria or bacteria-free supernatant fluid, newly synthesized bacterial ribonucleic acid (RNA) is recovered in animal cells. It appears that the presence of bacterial deoxyribonucleic acid (DNA)-dependent RNA polymerase is necessary for the transcription o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.114.1.114-120.1973
更新日期:1973-04-01 00:00:00
abstract::Rhizobactin 1021 is a hydroxymate siderophore produced by the soil bacterium Sinorhizobium meliloti 2011. A regulon comprising rhtA, encoding the outer membrane receptor protein for the ferrisiderophore; the biosynthesis operon rhbABCDEF; and rhrA, the Ara-C-like regulator of the receptor and biosynthesis genes has be...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.10.2996-3005.2004
更新日期:2004-05-01 00:00:00