Peanut rhizobia under salt stress: role of trehalose accumulation in strain ATCC 51466

1995 ◽  
Vol 41 (11) ◽  
pp. 1021-1030 ◽  
Author(s):  
Nora E. Ghittoni ◽  
Miguel A. Bueno
Keyword(s):  
Stationary Phases ◽  
Carbon Sources ◽  
Growth Behavior ◽  
Compatible Solute ◽  
Lag Phase ◽  
Strain Atcc ◽  
Bacterial Cultures ◽  
Patterns Of Utilization ◽  
Rhizobium Sp

Strain ATCC 51466, a motile peanut Rhizobium sp., showed patterns of utilization of diverse carbon sources characteristic of fast growers. Bacteria had periplasmic neutral glucans with molecular weight close to 3000. When the extracellular concentration of NaCl was raised to 400 mM, the lag phase of the culture was prolonged about threefold and the generation time was increased almost twice. The changes in growth behavior of salt-stressed bacteria were accompanied by the full suppression of periplasmic oligoglucans and the accumulation of cellular trehalose. Almost identical changes in cell-associated oligoglucans were observed after exposing peanut Rhizobium sp. strain ATCC 10317 to hypersalinity. When the osmotic pressure of the medium was augmented by the addition of either 200 mM mannitol or 16% (w/v) polyethylene glycol, cells of strain ATCC 51466 contained decreased levels of oligoglucans and accumulated trehalose. On the other hand, the content of cellular trehalose increased throughout logarithmic and stationary phases of growth of strain ATCC 51466 in a medium supplemented with 400 mM NaCl. When bacterial cultures were shifted from hypersaline to basal media, oligoglucans were the only oligosaccharides detected. The addition of 10 mM proline to bacteria grown under hypersalinity led to a 50% decrease in the level of trehalose and to the accumulation of oligoglucans. The addition of 10 mM glycine betaine to bacteria grown under hypersalinity also produced accumulation of oligoglucans, but the level of trehalose did not decrease. The results presented here are consistent with a role for trehalose as a compatible solute in peanut Rhizobium ATCC 51466, and they suggest that exogenously added proline may act as a compatible solute in preference to trehalose.Key words: periplasmic glucans, trehalose, peanut Rhizobium, osmotic stress.

The adaptation of bacterial cultures during the lag phase in media containing new substrates or antibacterial agents

1957 ◽  
Vol 242 (1228) ◽  
pp. 143-143 ◽  
Keyword(s):  
Adaptive Response ◽  
Liquid Culture ◽  
Antibacterial Agents ◽  
Carbon Sources ◽  
Lag Phase ◽  
Liquid Media ◽  
Bacterial Cultures ◽  
Solid Media ◽  
Mutant Cells ◽  
Selection Of

(This paper has been published in full in Proceedings B, 147, 247) Of a series of seventeen experiments in which cells of Bact. coli mutabile and Bact. coli ( K 12) were allowed to lag in media containing all the materials necessary for growth and division, but with lactose and D-arabinose or dulcitol respectively as sole carbon sources, there were eight experiments in which it was found, when samples were withdrawn at intervals during the lag phase and were plated on solid media containing the same carbon source, that the longer the cells had remained in the liquid medium the shorter was the plate lag. Since the majority of the cells in the liquid culture took part in this response it is interpreted as an adaptation involving the bulk of the population and does not represent the selection of a few mutant cells. In the other nine experiments the reduction in lag was also observed, but since the growth of the culture took place almost simultaneously with this reduction it was not possible to draw any definite conclusion from them. In another experiment involving the adaptation of Bact. coli mutabile to resist chloramphenicol, a definite adaptive response was again obtained. Similar experiments in liquid media lacking a nitrogen source or in phosphate buffer show that the adaptation of Bact. coli mutabile to lactose and to chloramphenicol and that of Bact. lactis aerogenes to D-arabinose in the presence of streptomycin can also go a considerable way in media which do not contain all the materials necessary for growth and division. Here again it is not necessary to postulate the presence of special mutant cells.

scholarly journals Role of Ori in Thermococcus barophilus

2021 ◽  
Author(s):  
Yann Moalic ◽  
Ryan Catchpole ◽  
Elodie Leroy ◽  
Logan Mc Teer ◽  
Valérie Cueff-Gauchard ◽  
...  
Keyword(s):  
Dna Replication ◽  
Genomic Dna ◽  
Replication Origin ◽  
Gene Deletion ◽  
Reference Strain ◽  
Stationary Phases ◽  
Exponential Phase ◽  
Lag Phase ◽  
Origin Of Replication

SummaryThe mechanisms underpinning replication of genomic DNA in Archaea have recently been challenged. Species belonging to two different taxonomic orders grow well in the absence of an origin of replication, challenging the role of the replication origin in these organisms. Here, we pursue the investigation of the particular way some archaea manage their DNA replication with Thermococcus barophilus and the role of Ori in this Archaea. Surprisingly we discovered that T. barophilus uses its Ori all along the growth curve with marked increase at the end of exponential phase. Through gene deletion, we show that Ori utilization requires Cdc6, and that origin deletion results in increased time in lag phase and a moderate decrease of growth rate in mutants. The number of chromosomes are quite similar between both strains during exponential and early stationary phases but differs after 24h of growth where ΔTbOriC has only 6 chromosomes/cell compared to 10 for the reference strain (WT). Following 1hr of growth in fresh media, ΔTbOriC strains contains 3 chromosome copies/cell, whereas the WT contains only 1. We hypothesize that the T. barophilus might degrade DNA to obtain energy to start replication and cell division, whereas the ΔTbOriC must maintain more chromosomal copies in order to initiate DNA replication in the absence of an origin or replication. Finally, we analyzed the role of Ori at temperatures above or below the optimal temperature, revealing that Ori is important to start growth at those temperatures, suggesting that replication origins may be involved in stress response.

The Formation of Intermediate Product I in a Purified System The Role of Factor IX or of its Precursor and of a Hageman Factor-PTA Fraction

1961 ◽  
Vol 6 (02) ◽  
pp. 224-234 ◽  
Author(s):  
E. T Yin ◽  
F Duckert
Keyword(s):  
Intermediate Product ◽  
Factor Ix ◽  
Assay Method ◽  
Lag Phase ◽  
Factor X ◽  
Haemophilia B ◽  
Hageman Factor ◽  
One Stage ◽  
The One

Summary1. The role of two clot promoting fractions isolated from either plasma or serum is studied in a purified system for the generation of intermediate product I in which the serum is replaced by factor X and the investigated fractions.2. Optimal generation of intermediate product I is possible in the purified system utilizing fractions devoid of factor IX one-stage activity. Prothrombin and thrombin are not necessary in this system.3. The fraction containing factor IX or its precursor, no measurable activity by the one-stage assay method, controls the yield of intermediate product I. No similar fraction can be isolated from haemophilia B plasma or serum.4. The Hageman factor — PTA fraction shortens the lag phase of intermediate product I formation and has no influence on the yield. This fraction can also be prepared from haemophilia B plasma or serum.

scholarly journals Studies on the Role of the are a Gene in the Regulation of Nitrogen Catabolism in Aspergillus nidulans

1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes
Keyword(s):  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Selection Methods ◽  
Growth Responses ◽  
Dominance Relationships ◽  
Regulatory Circuits ◽  
Specific Activities

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.

The role of iron in the preparation and oxygen reduction reaction activity of nitrogen-doped carbon

2015 ◽  
Vol 51 (12) ◽  
pp. 2450-2453 ◽  
Author(s):  
Dae-Soo Yang ◽  
Min Young Song ◽  
Kiran Pal Singh ◽  
Jong-Sung Yu
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Carbon Sources ◽  
Reduction Reaction ◽  
Acidic Media ◽  
Oxygen Reduction Reaction Activity ◽  
Exact Role ◽  
Ordered Mesoporous ◽  
Nitrogen Doped Carbon

The exact role of iron in catalyzing oxygen reduction reaction in both alkaline and acidic media is portrayed with unique platelet ordered mesoporous carbon prepared using Fe-phthalocyanine as iron, nitrogen and carbon sources.

scholarly journals Accumulation of viruslike particles in a yeast mutant lacking a mitochondrial pore protein.

1989 ◽  
Vol 9 (3) ◽  
pp. 1100-1108 ◽  
Author(s):  
M Dihanich ◽  
E van Tuinen ◽  
J D Lambris ◽  
B Marshallsay
Keyword(s):  
Carbon Sources ◽  
Lag Phase ◽  
Cytosol Fraction ◽  
Mitochondrial Porin ◽  
Mitochondrial Functions ◽  
Microsome Fraction ◽  
Simultaneous Loss ◽  
Viruslike Particles ◽  
Mutant Cells ◽  
Pore Protein

The lack of mitochondrial porin is not lethal in Saccharomyces cerevisiae, but it impairs some respiratory functions and, therefore, growth on nonfermentable carbon sources such as glycerol. However, after a lag phase porinless mutant cells adapt to growth on glycerol, accumulating large amounts of an 86-kilodalton (kDa) protein (M. Dihanich, K. Suda, and G. Schatz, EMBO J. 6:723-728, 1987) and of a 5-kilobase RNA. Immunogold labeling localized the 86 kDa-protein exclusively to the cytosol fraction, although most of it cosedimented with the microsome fraction in earlier cell fractionations. This discrepancy was resolved when the 86-kDa protein was identified as the major coat protein in viruslike particles (VLPs) which is encoded by a double-stranded RNA (L-A RNA). Elimination of VLPs in the original porinless strain by introduction of the mak10 or the mak3 mutation increased the respiratory defect and prolonged its lag phase on nonfermentable carbon sources. The fact that the simultaneous loss of VLPs and respiratory functions are the introduction of mak10 or mak3 occurred even in some porin-containing wild-type strains suggests that there is a link between VLP and mitochondrial functions.

scholarly journals Alternative Sigma Factor SigK Has a Role in Stress Tolerance of Group I Clostridium botulinum Strain ATCC 3502

2013 ◽  
Vol 79 (12) ◽  
pp. 3867-3869 ◽  
Author(s):  
Elias Dahlsten ◽  
David Kirk ◽  
Miia Lindström ◽  
Hannu Korkeala
Keyword(s):  
Stress Tolerance ◽  
Sigma Factor ◽  
Clostridium Botulinum ◽  
Alternative Sigma Factor ◽  
Strain Atcc ◽  
Content Type ◽  
Osmotic Stress Tolerance ◽  
Group I ◽  
Temperature Downshift

ABSTRACTThe role of the alternative sigma factor SigK in cold and osmotic stress tolerance ofClostridium botulinumATCC 3502 was demonstrated by induction ofsigKafter temperature downshift and exposure to hyperosmotic conditions and by impaired growth of thesigKmutants under the respective conditions.

scholarly journals Role of single and mixed culture of Pseudomonas aeruginosa and Serratia ficaria in utilization of petroleum wastes of Dora- refineries.

2007 ◽  
Vol 4 (4) ◽  
pp. 542-548
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mixed Culture ◽  
Bacterial Culture ◽  
Bacterial Cultures ◽  
Viable Cells ◽  
Nacl Concentration ◽  
Agitated Culture ◽  
Growth Of Bacteria ◽  
Better Than

The ability of single and mixed bacterial culture to utilize Dora-refineries petroleum wastes was compared. Pseudomonas aeruginosa and Serratia ficaria mixed culture consumed the wastes better than the single bacterial cultures. The highest log. number of viable cells in mixed culture was 6.842 , while in single bacterial cultures it was 6.683 and 5.631, respectively. after 3 days in API medium containing the refinery wastes. The effect of some environmental conditions on the degradation of petroleum wastes was studied included aeration , NaCl concentration , pH and temperature. The growth of bacteria in the agitated culture was higher than stagnant culture the log. of cell no. was 6.021 in the first culture. The highest log. of cell no. stagnant culture was 5.771. Pseudomonas aeruginosa AA22 and Serratia ficaria AA39 were able to grow in medium containing 5 , 7 % NaCl , they favorite pH 7. The mixed culture of the two bacteria grew well of 45 oC.

Role of RpoS and MutS in phase variation of Pseudomonas sp. PCL1171

Microbiology ◽  
2005 ◽  
Vol 151 (5) ◽  
pp. 1403-1408 ◽  
Author(s):  
Daan van den Broek ◽  
Thomas F. C. Chin-A-Woeng ◽  
Guido V. Bloemberg ◽  
Ben J. J. Lugtenberg
Keyword(s):  
Growth Rate ◽  
High Frequency ◽  
Constitutive Expression ◽  
Phase Variation ◽  
Lag Phase ◽  
Pseudomonas Sp ◽  
Spontaneous Mutations ◽  
Stationary Growth ◽  
The Relationship

Pseudomonas sp. strain PCL1171 undergoes reversible colony phase variation between opaque phase I and translucent phase II colonies, which is dependent on spontaneous mutations in the regulatory genes gacA and gacS. Mutation of the mutS gene and constitutive expression of rpoS increases the frequency at which gac mutants appear 1000- and 10-fold, respectively. Experiments were designed to study the relationship between gacS, rpoS and mutS. These studies showed that (i) a functional gac system is required for the expression of rpoS, (ii) RpoS suppresses the expression of mutS and therefore increases the frequency of gac mutants, and (iii) upon mutation of rpoS and gacS, the expression of mutS is increased. Mutation of gacS abolishes suppression of mutS expression in stationary growth, suggesting that additional gac-dependent factors are involved in this suppression. In conclusion, inefficient mutation repair via MutS, of which the expression is influenced by gacA/S itself and by rpoS in combination with other factors, contributes to the high frequency of mutations accumulating in gacA/S. The role of RpoS in the growth advantage of a gac mutant was analysed, and mutation of rpoS only reduced the length of the lag phase, but did not affect the growth rate, suggesting a role for both RpoS and a reduction of metabolic load in the growth advantage of a gac mutant.

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