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or dulcitol respectively as sole carbon sources, there were eight experiments in which it was found, when samples were withdrawn at intervals during the lag phase and were plated on solid media containing the same carbon source, that the longer the cells had remained in the liquid medium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 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.

Limiting Conditions of Temperature and pH for Growth of “Thermophilic” Campylobacters on Solid Media

1983 ◽  
Vol 46 (9) ◽  
pp. 767-768 ◽  
Author(s):  
C. O. GILL ◽  
LYNDA M. HARRIS
Keyword(s):  
Nalidixic Acid ◽  
Campylobacter Jejuni ◽  
Liquid Culture ◽  
Campylobacter Coli ◽  
Liquid Media ◽  
Ph Values ◽  
Solid Media ◽  
Temperature Ranges ◽  
Type Strains

Strains of Campylobacter previously used for studies with meat, included strains distinguishable as Campylobacter jejuni and nalidixic acid-resistant thermophilic campylobacters (NARTC). The pH and temperature minima for growth on agar plates were determined for 12 strains: six strains used in the meat studies (four C. jejuni, two NARTC), three type strains (C. jejuni, Campylobacter coli, NARTC) and three strains of C. jejuni whose pH and temperature ranges in liquid culture had been determined by other workers. Heavy, visible inocula of most strains grew at temperatures 2°C lower and pH values 0.2 or 0.3 unit lower than the minima observed with light inocula. For all strains of C. jejuni, values for temperature and pH minima from heavy inocula, 32°C and pH 5.1, were comparable with those reported for growth of three strains in liquid media. The pH minima for NARTC strains (pH 5.8) were higher than those for C. jejuni, but temperature minima were similar.

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.

An investigation of the nature of certain adaptive changes in bacteria

1950 ◽  
Vol 136 (885) ◽  
pp. 562-576 ◽  
Keyword(s):  
Amino Acid ◽  
Acid Medium ◽  
Ammonium Sulphate ◽  
Sodium Citrate ◽  
Nitrogen Sources ◽  
Lag Phase ◽  
Test Medium ◽  
Liquid Media ◽  
Adaptive Changes ◽  
Solid Media

Four strains of bacteria which, until trained, show a long lag before they will utilize certain new carbon or nitrogen sources, have been examined by methods involving the transfer of inocula at widely varying dilutions to liquid or solid media containing the new substrate. The strains and sources studied are ( a ) Bact. lactis aerogenes and D-arabinose, ( b ) Bact. coli mutabile and lactose , ( c ) Bact. coli and ammonium sulphate, ( d ) a coli-aerogenes intermediate and sodium citrate. With ( a ) and ( b ) in solid and liquid media and ( d ) in liquid media all or most of the dilutions which are viable in a glucose-amino-acid medium (which supports growth without lag) also show growth, though after considerable delay, in the new medium. With ( c ) the proportion of cells which grow is small and, even for parallel inocula, very sensitive to minute changes in the test medium. But in general the reason why many cells fail to grow is found to be that they have died before they have traversed the lag phase which necessarily precedes their development. The bearing of these observations on theories of mutation and adaptation is considered.

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.

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

scholarly journals Penicillium Antibiotic Effect

2018 ◽  
Vol 80 (7) ◽  
pp. 530-535
Author(s):  
Jesse A. Lewis ◽  
Nadja Anderson
Keyword(s):  
Experimental Design ◽  
Natural Product ◽  
Penicillium Chrysogenum ◽  
Liquid Culture ◽  
Bacterial Culture ◽  
Fungal Spore ◽  
Culture Density ◽  
Solid Media ◽  
Antibiotic Effect ◽  
Laboratory Cultures

In this lesson students will use the Penicillium chrysogenum fungus, which naturally produces the antibiotic penicillin, to investigate the effect of naturally produced antibiotics on bacteria in laboratory cultures. Students co-culture P. chrysogenum with three species of bacteria to observe differences between penicillin-resistant and penicillin-sensitive bacteria. They will normalize fungal spore suspension and bacterial culture concentrations before inoculating co-cultures. After bacteria have been exposed to the antibiotic, students will quantify culture density to determine antibiotic effect in liquid culture and on solid media. Students will learn about natural product antibiotics as well as experimental design and application.

Activity of myxin against Ceratocystis ulmi

1969 ◽  
Vol 15 (1) ◽  
pp. 133-135 ◽  
Author(s):  
E. A. Peterson
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Liquid Culture ◽  
Inhibitory Concentration ◽  
In Vitro Tests ◽  
Strong Inhibition ◽  
Solid Media ◽  
Highly Sensitive ◽  
Paper Disc ◽  
Disc Assay

Eight strains of Ceratocystis ulmi originating from different locations and host species were found to be highly sensitive to the antibiotic myxin in in vitro tests. By paper disc assay, amounts as low as 0.5–1.0 μg caused strong inhibition of the fungus on solid media. The minimum inhibitory concentration in liquid culture was 0.2 μg/ml and levels of antibiotic above this concentration proved to be fungicidal.

scholarly journals Screening of local wild-type Xanthomonas spp. for xanthan biosynthesis using media with different carbon sources

2021 ◽  
Vol 26 (4) ◽  
pp. 2800-2807
Author(s):  
IDA ZAHOVIĆ ◽  
JELENA DODIĆ ◽  
SINIŠA MARKOV ◽  
JOVANA GRAHOVAC ◽  
MILA GRAHOVAC ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Carbon Source ◽  
Carbon Sources ◽  
Wild Type ◽  
Biotechnological Production ◽  
Aerobic Conditions ◽  
Pepper Leaves ◽  
Synthetic Media ◽  
Selection Of

In this study the screening of different Xanthomonas strains, isolated from infected crucifers and pepper leaves, for xanthan biosynthesis on semi-synthetic media containing different carbon sources was performed. The success of xanthan biosynthesis was estimated based on xanthan concentration in media and its molecular weight. Glucose and glycerol were investigated as carbon sources in a quantity of 20.0 g/L. Xanthan biosynthesis by different Xanthomonas isolates on two different cultivation media was carried out in Erlenmeyer flasks under aerobic conditions for 168 h. According to the obtained results selection of the carbon source, producing strain and their combination have a statistically significant effect on xanthan quantity and quality. The results obtained in this study indicate that local wild-type Xanthomonas strains isolated from pepper leaves have a great potential for application in biotechnological production of good-quality xanthan on glycerol-based media.

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