Axenic culture of myxamoebae of the myxomycete Echinostelium minutum

1970 ◽  
Vol 48 (3) ◽  
pp. 663-664 ◽  
Author(s):  
Edward F. Haskins
Keyword(s):  
Stationary Phase ◽  
Generation Time ◽  
Axenic Culture ◽  
Serial Passage ◽  
Logarithmic Phase ◽  
First Time ◽  
Axenic Cultivation ◽  
Average Generation Time

Axenic cultivation of the myxomycete Echinostelium minutum De Bary (Echinosteliales) is reported for the first time. After more than a year of serial passage the average generation time of amoebae during the logarithmic phase is 18 h and a stationary phase yield of over 2 × 106 cells/ml is typical.

Oxygen requirements of strains of Pseudomonas and Achromobacter

1972 ◽  
Vol 18 (3) ◽  
pp. 321-326 ◽  
Author(s):  
D. S. Clark ◽  
T. Burki
Keyword(s):  
Growth Rate ◽  
Stationary Phase ◽  
Oxygen Concentration ◽  
Generation Time ◽  
Logarithmic Phase ◽  
Nutrient Media ◽  
Meat Spoilage ◽  
Oxygen Oxygen ◽  
Lag Period ◽  
Oxygen Requirements

Studies on the oxygen requirements of aerobic psychrotolerant bacteria showed that the oxygen concentration of the atmosphere can be lowered to 2% without noticeably inhibiting growth rate. Tests were made with meat-spoilage strains of Achromobacter and Pseudomonas in nutrient media sparged with gases containing from 0.1 to 100% oxygen. Reduction of overall growth rate with reduction in oxygen concentration below 2% was mainly the result of an increase in the lag period. At an oxygen concentration of 0.5% or lower, however, cell generation time during the logarithmic phase was increased and cell yield at the stationary phase was reduced. The increased lag period could be eliminated by using an inoculum adapted to the oxygen concentration under test. Growth did not occur in the absence of oxygen. Oxygen concentrations greater than 21% (air) had a negligible effect on Pseudomonas, but inhibited the growth rate of Achromobacter. The results indicate that insufficient oxygen is not a major cause of the failure of these bacteria to grow rapidly in vacuum packaged meats.

scholarly journals Construction and Characterization of aMycobacterium tuberculosis Mutant Lacking the Alternate Sigma Factor Gene, sigF

2000 ◽  
Vol 68 (10) ◽  
pp. 5575-5580 ◽  
Author(s):  
Ping Chen ◽  
Rafael E. Ruiz ◽  
Qing Li ◽  
Richard F. Silver ◽  
William R. Bishai
Keyword(s):  
Stationary Phase ◽  
Sigma Factor ◽  
Type Strain ◽  
Wild Type Strain ◽  
Axenic Culture ◽  
Wild Type ◽  
Intracellular Growth ◽  
Factor Gene ◽  
Time To Death

ABSTRACT The alternate RNA polymerase sigma factor gene, sigF, which is expressed in stationary phase and under stress conditions in vitro, has been deleted in the virulent CDC1551 strain ofMycobacterium tuberculosis. The growth rate of the ΔsigF mutant was identical to that of the isogenic wild-type strain in exponential phase, although in stationary phase the mutant achieved a higher density than the wild type. The mutant showed increased susceptibility to rifampin and rifapentine. Additionally, the ΔsigF mutant displayed diminished uptake of chenodeoxycholate, and this effect was reversed by complementation with a wild-type sigF gene. No differences in short-term intracellular growth between mutant and wild-type organisms within human monocytes were observed. Similarly, the organisms did not differ in their susceptibilities to lymphocyte-mediated inhibition of intracellular growth. However, mice infected with the ΔsigF mutant showed a median time to death of 246 days compared with 161 days for wild-type strain-infected animals (P < 0.001). These data indicate that M. tuberculosis sigF is a nonessential alternate sigma factor both in axenic culture and for survival in macrophages in vitro. While the ΔsigF mutant produces a lethal infection of mice, it is less virulent than its wild-type counterpart by time-to-death analysis.

scholarly journals Induction of the synthesis of an additional family of long-chain dolichols in the yeast Saccharomyces cerevisiae. Effect of starvation and ageing.

2002 ◽  
Vol 49 (3) ◽  
pp. 781-787 ◽  
Author(s):  
Anna Szkopinska ◽  
Ewa Swiezewska ◽  
Joanna Rytka
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stationary Phase ◽  
Yeast Cells ◽  
Logarithmic Phase ◽  
Cellular Membranes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chemical Changes ◽  
Physico Chemical ◽  
Long Chain

The yeast Saccharomyces cerevisiae strain W303 synthesizes in the early logarithmic phase of growth dolichols of 14-18 isoprene residues. The analysis of the polyisoprenoids present in the stationary phase revealed an additional family which proved to be also dolichols but of 19-24 isoprene residues, constituting 39% of the total dolichols. The transfer of early logarithmic phase cells to a starvation medium lacking glucose or nitrogen resulted in the synthesis of the longer chain dolichols. The additional family of dolichols represented 13.8% and 10.3% of total dolichols in the glucose and nitrogen deficient media, respectively. The level of dolichols in yeast cells increased with the age of the cultures. Since both families of dolichols are present in stationary phase cells we postulate that the longer chain dolichols may be responsible for the physico-chemical changes in cellular membranes allowing yeast cells to adapt to nutrient deficient conditions to maintain long-term viability.

scholarly journals Delimitation, new species and teleomorph-anamorph relationships in Codinaea, Dendrophoma, Paragaeumannomyces and Striatosphaeria (Chaetosphaeriaceae)

MycoKeys ◽  
2020 ◽  
Vol 74 ◽  
pp. 17-74
Author(s):  
Martina Réblová ◽  
Jana Nekvindová ◽  
Jacques Fournier ◽  
Andrew N. Miller
Keyword(s):  
New Species ◽  
Type Species ◽  
Morphological Traits ◽  
Phylogenetic Analyses ◽  
Axenic Culture ◽  
Monophyletic Clade ◽  
Morphological Comparison ◽  
The Family ◽  
Terrestrial Habitats ◽  
First Time

The Chaetosphaeriaceae are a diverse group of pigmented, predominantly phialidic hyphomycetes comprised of several holomorphic genera including Chaetosphaeria, the most prominent genus of the family. Although the morphology of the teleomorphs of the majority of Chaetosphaeria is rather uniform, their associated anamorphs primarily exhibit the variability and evolutionary change observed in the genus. An exception from the morphological monotony among Chaetosphaeria species is a group characterised by scolecosporous, hyaline to light pink, multiseptate, asymmetrical ascospores and a unique three-layered ascomatal wall. Paragaeumannomyces sphaerocellularis, the type species of the genus, exhibits these morphological traits and is compared with similar Chaetosphaeria with craspedodidymum- and chloridium-like synanamorphs. Morphological comparison and phylogenetic analyses of the combined ITS-28S sequences of 35 isolates and vouchers with these characteristics revealed a strongly-supported, morphologically well-delimited clade in the Chaetosphaeriaceae containing 16 species. The generic name Paragaeumannomyces is applied to this monophyletic clade; eight new combinations and five new species, i.e. P. abietinussp. nov., P. eleganssp. nov., P. granulatussp. nov., P. sabinianussp. nov. and P. smokiensissp. nov., are proposed. A key to Paragaeumannomyces is provided. Using morphology, cultivation studies and phylogenetic analyses of ITS and 28S rDNA, two additional new species from freshwater and terrestrial habitats, Codinaea paniculatasp. nov. and Striatosphaeria castaneasp. nov., are described in the family. A codinaea-like anamorph of S. castanea forms conidia with setulae at each end in axenic culture; this feature expands the known morphology of Striatosphaeria. A chaetosphaeria-like teleomorph is experimentally linked to Dendrophoma cytisporoides, a sporodochial hyphomycete and type species of Dendrophoma, for the first time.

scholarly journals Silica bound co-pillar[4+1]arene as a novel supramolecular stationary phase

2020 ◽  
Vol 56 (12) ◽  
pp. 1792-1794 ◽  
Author(s):  
Subbareddy Mekapothula ◽  
Matthew A. Addicoat ◽  
David J. Boocock ◽  
John D. Wallis ◽  
Peter J. Cragg ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Stationary Phase ◽  
First Time

A novel co-pillar[4+1]arene has been synthesised for the first time, using microwave irradiation and utilised as a chromatographic stationary phase.

Layer-by-layer self-assembly of polydopamine/gold nanoparticle/thiol coating as the stationary phase for open tubular capillary electrochromatography

2015 ◽  
Vol 7 (19) ◽  
pp. 8227-8234 ◽  
Author(s):  
Xiu-Ju Li ◽  
Qi-Feng Fu ◽  
Qi-Hui Zhang ◽  
Xue-Mei Jiang ◽  
Feng-Qing Yang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Stationary Phase ◽  
Gold Nanoparticle ◽  
Self Assembly ◽  
Capillary Electrochromatography ◽  
Phase Ratio ◽  
Layer By Layer ◽  
Novel Method ◽  
First Time ◽  
High Phase

A novel method for the preparation of permanent coating columns with a high phase ratio based on the multiple properties of PDA and LBL self-assembly of polydopamine/gold nanoparticles/thiols has been developed for the first time.

Treatment of Tannery Wastewater with Salt Tolerant Bacteria Basing on Different Culture Mediums

2011 ◽  
Vol 403-408 ◽  
pp. 625-633
Author(s):  
Jun Guo He ◽  
Fei Liu ◽  
Bao Ping Han ◽  
Bo Wei Zhao ◽  
Jian Liu
Keyword(s):  
Generation Time ◽  
Total Concentration ◽  
Morphological Characteristics ◽  
Volume Ratio ◽  
Tannery Wastewater ◽  
Intermittent Aeration ◽  
Salt Tolerant ◽  
Pure Salt ◽  
Aerobic Sludge ◽  
Average Generation Time

This study was done to access the influence of salinity on the treatment of tannery wastewater, activity of sludge and morphological characteristics of the salt-tolerant bacteria cultivated using tannery wastewater as culture mediums and intermittent aeration as method. The results indicated that， aerobic sludge which contained salt-tolerant bacteria was cultivated under the conditions of temperature of 35°C and pH = 8, the COD removal in simulated and actual tannery wastewater was more than 87% and 85% by the cultivated aerobic sludge, respectively. In addition, the morphological characteristics were related to the composition and concentration of the salt. The average generation time of bacteria was 24.6min ~ 28.6min when the concentration of MLSS was 2.0 ~ 3.0g/L and the concentration of pure NaCl was 1 ~ 5g/L. As the volume ratio of NaCl and Na2SO4 was 4:1 ~ 1:4 with the total concentration of 5g/L, the average generation time of bacteria was 30.8min ~ 39.7min. The relation equation between salt concentration and the average generation time of bacteria under the pure salt, composite salt and actual tannery wastewater conditions was also deduced through four assumptions. The results had significant application on tannery wastewater treatment with great reduction of pollution.

Speciation of 2′-deoxymugineic acid–metal complexes in top soil extracts by multi-modal stationary phase LC-ICP-MS

2015 ◽  
Vol 30 (6) ◽  
pp. 1345-1355 ◽  
Author(s):  
Y. Schindlegger ◽  
E. Oburger ◽  
M. Puschenreiter ◽  
G. Stingeder ◽  
G. Koellensperger ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Metal Complexes ◽  
Mixed Mode ◽  
Soil Extracts ◽  
Icp Ms ◽  
Top Soil ◽  
Deoxymugineic Acid ◽  
First Time

For the first time a mixed mode stationary phase was implemented for the speciation of 2′-deoxymugineic acid–metal complexes in soil related samples.

scholarly journals Evidence for Contribution of Neutral Trehalase in Barotolerance of Saccharomyces cerevisiae

2000 ◽  
Vol 66 (12) ◽  
pp. 5182-5185 ◽  
Author(s):  
Hitoshi Iwahashi ◽  
Solomon Nwaka ◽  
Kaoru Obuchi
Keyword(s):  
Hydrostatic Pressure ◽  
Stationary Phase ◽  
Type Strain ◽  
Wild Type Strain ◽  
Glucose Repression ◽  
Logarithmic Phase ◽  
Wild Type ◽  
Neutral Trehalase ◽  
I Gene

ABSTRACT In yeast, trehalose accumulation and its hydrolysis, which is catalyzed by neutral trehalase, are believed to be important for thermotolerance. We have shown that trehalose is one of the important factors for barotolerance (resistance to hydrostatic pressure); however, nothing is known about the role of neutral trehalase in barotolerance. To estimate the contribution of neutral trehalase in resisting high hydrostatic pressure, we measured the barotolerance of neutral trehalase I and/or neutral trehalase II deletion strains. Under 180 MPa of pressure for 2 h, the neutral trehalase I deletion strain showed higher barotolerance in logarithmic-phase cells and lower barotolerance in stationary-phase cells than the wild-type strain. Introduction of the neutral trehalase I gene (NTH1) into the deletion mutant restored barotolerance defects in stationary-phase cells. Furthermore, we assessed the contribution of neutral trehalase during pressure and recovery conditions by varying the expression ofNTH1 or neutral trehalase activity with a galactose-inducible GAL1 promoter with either glucose or galactose. The low barotolerance observed with glucose repression of neutral trehalase from the GAL1 promoter was restored during recovery with galactose induction. Our results suggest that neutral trehalase contributes to barotolerance, especially during recovery.

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