Extracellular ribonuclease secretion by Ustilago hordei

1971 ◽  
Vol 49 (11) ◽  
pp. 2035-2039
Author(s):  
N. T. Bech-Hansen ◽  
C. O. Person
Keyword(s):  
Stationary Phase ◽  
Gel Electrophoresis ◽  
Inorganic Phosphate ◽  
Culture Media ◽  
Phosphate Concentration ◽  
Glucose Content ◽  
Ustilago Hordei ◽  
Parasitic Phase

RNase assays and gel electrophoresis of culture media have provided evidence that U. hordei, grown in vitro during the haploid (non-parasitic) phase, produced several extracellular RNases. The secretion of the RNases occurred during the end of log phase and at the beginning of stationary phase. Secretion was not affected by the addition of RNA, or by varying the inorganic phosphate concentration; it was enhanced in media of increased glucose content.

Arbuscular mycorrhizal responsiveness of in vitro tomato root lines is not related to growth and nutrient uptake rates

2003 ◽  
Vol 81 (7) ◽  
pp. 645-656 ◽  
Author(s):  
Karine Labour ◽  
Mario Jolicoeur ◽  
Marc St-Arnaud
Keyword(s):  
Nutrient Uptake ◽  
Hairy Root ◽  
Hairy Roots ◽  
Inorganic Phosphate ◽  
Minimal Medium ◽  
Glomus Intraradices ◽  
Phosphate Concentration ◽  
Tomato Cultivar ◽  
Uptake Rates

Variability in growth and nutritional dynamics of in vitro tomato hairy root lines and their relationship with responsiveness to mycorrhizal colonization were studied. Four tomato cultivars were transformed with three Agrobacterium rhizogenes strains to obtain several hairy root lines, which were compared for growth and receptivity to Glomus intraradices. Four transformed hairy root lines were further characterized and compared with excised roots of the nontransformed tomato cultivar 'Cobra' and with Ri-T-DNA carrot hairy roots. Lines were compared during 4 months on minimal medium in terms of growth, nutrient uptake, and mycorrhizal colonization. In a subexperiment, the cultures were grown on a modified minimal medium to assess the contribution of initial inorganic phosphate concentration in mycorrhizal susceptibility of the three initially nonreceptive lines. On minimal medium, growth and nutrient uptake rates were highly correlated, but both were unrelated to mycorrhizal receptiveness. All the lines successfully established the symbiosis when the initial phosphate concentration was significantly reduced. No association was found between the origin of lines from the different tomato cultivar – bacterial strain combinations and the absence of symbiosis establishment on minimal medium. Decrease of inorganic phosphate concentration at the beginning of the culture was a key factor involved in precolonization steps of mycorrhizal symbiosis.Key words: Glomus intraradices, hairy roots, Lycopersicon esculentum, mycorrhizal responsiveness, root nutrition, inorganic phosphate.

scholarly journals In vitro germination of zygotic embryos of hybrid BRS Manicoré (E. guineensis X E. oleifera)

2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1841-1850
Author(s):  
KEILA A.P. BONETTI ◽  
MARGUERITE QUOIRIN ◽  
REGINA C. QUISEN ◽  
SUELEN C.S. LIMA
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Germination Rate ◽  
Phosphate Concentration ◽  
Zygotic Embryos ◽  
In Vitro Germination ◽  
N6 Medium ◽  
Whole Plants ◽  
Tetrazolium Test

ABSTRACT The interspecific oil palm hybrid BRS Manicoré (E. guineensis x E. oleifera) has superior agronomic characteristics. However, the germination rate is low (30%) and the process is slow when the seeds are sown in a conventional form. The purpose of this study was to optimize the in vitro germination of zygotic embryos of this hybrid comparing seed lots. The viability of zygotic embryos was evaluated by the tetrazolium test (0.075%) for 4 h. The embryos were cultured on MS and Y3 culture media, with and without the addition of NaH2PO4, as well as on MS, MS1/2 and N6 medium. In MS medium containing NaH2PO4, the germination rate was increased from 40 to 70% in comparison with the medium without sodium phosphate. The comparison between the culture media MS, MS 1/2, N6 and Y3 showed that 75% of zygotic embryos cultured in the Y3 medium formed whole plants (with roots and shoots defined), a higher percentage than embryos cultured on MS, MS 1/2 and N6 media (46, 35 and 17% respectively). In the same Y3 culture medium, the embryos were larger (36% ≥ 2 cm and 30% ≥ 5 cm) than in the other media. Results obtained by the tetrazolium test were similar to those of germination, showing the effect of the genotype of each seed lot. For the germination and development of plantlets it is essential to add NaH2PO4 to a culture medium containing no phosphate or with a low phosphate concentration.

scholarly journals In vitro Inorganic Phosphate Solubilization Tests of Cowpea Root Nodule Bacteria from Ethiopia

2020 ◽  
Author(s):  
Girmaye Kenasa ◽  
B.C. Nandeshwar ◽  
Fassil Assefa
Keyword(s):  
Inorganic Phosphate ◽  
Crop Production ◽  
Root Nodule ◽  
Phosphate Solubilization ◽  
Culture Media ◽  
Bacterial Species ◽  
Alkaline Soil ◽  
Ph Change ◽  
Agar Media

Background: Phosphorus is one of the limiting plant nutrients in most soil due to its fixation with metal ions both in acidic and alkaline soil. However, some soil bacteria have potential to solubilize the cation-fixed phosphorus and make it available to plants.Methods: Sixty-six cowpea root nodule bacterial species were tested for inorganic phosphate solubilization (PS). PS potential of the isolates from Ca3 (PO4)2, AlPO4 and FePO4 were tested on four different kinds of agar media. Solublization efficiency was determined as Solubilization Index (SI) on agar media and quantity of bioavailable phosphorous on broth media. Result: About 30% of the bacterial isolates, out of which 60% endophytes were Ca3 (PO4)2 solubilizers on Pikovskaya medium but did not grow on media containing AlPO4 and FePO4 as sole P sources. Isolates showed significant variation (p less than 0.05) in Ca3 (PO4)2 solubilization efficiency on the different culture media and ECE-21 (Pseudomonas putida) was versatile in solubilizing Ca3(PO4)2 from the four test media. However, ECE-26A (Bacillus subtilis) showed the highest PS in broth media (140.8 µg ml-1) indicating the moderate correlation (r=0.5578; p less than 0.05) of PS between solid and liquid media. Amounts of P solubilized and pH change of the culture filtrate was inversely correlated (r=-0.731; p less than 0.01). In general, ECE-21 was the most efficient P solubilizer (SI=2.67±0.1; P=87.74±7.4µg ml-1) solublizers and hence can be an ideal candidate as inoculants for the crop production in Ethiopia after field evaluation.

scholarly journals Very Low Ethanol Concentrations Affect the Viability and Growth Recovery in Post-Stationary-Phase Staphylococcus aureus Populations

2006 ◽  
Vol 72 (4) ◽  
pp. 2627-2636 ◽  
Author(s):  
Indranil Chatterjee ◽  
Greg A. Somerville ◽  
Christine Heilmann ◽  
Hans-Georg Sahl ◽  
Hans H. Maurer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Stationary Phase ◽  
Culture Medium ◽  
Culture Media ◽  
Growth Media ◽  
Cell Integrity ◽  
Amino Acid Depletion

ABSTRACT Pharmaceuticals, culture media used for in vitro diagnostics and research, human body fluids, and environments can retain very low ethanol concentrations (VLEC) (≤0.1%, vol/vol). In contrast to the well-established effects of elevated ethanol concentrations on bacteria, little is known about the consequences of exposure to VLEC. We supplemented growth media for Staphylococcus aureus strain DSM20231 with VLEC (VLEC+ conditions) and determined ultramorphology, growth, and viability compared to those with unsupplemented media (VLEC− conditions) for prolonged culture times (up to 8 days). VLEC+-grown late-stationary-phase S. aureus displayed extensive alterations of cell integrity as shown by scanning electron microscopy. Surprisingly, while ethanol in the medium was completely metabolized during exponential phase, a profound delay of S. aureus post-stationary-phase recovery (>48 h) was observed. Concomitantly, under VLEC+ conditions, the concentration of acetate in the culture medium remained elevated while that of ammonia was reduced, contributing to an acidic culture medium and suggesting decreased amino acid catabolism. Interestingly, amino acid depletion was not uniformly affected: under VLEC+ conditions, glutamic acid, ornithine, and proline remained in the culture medium while the uptake of other amino acids was not affected. Supplementation with arginine, but not with other amino acids, was able to restore post-stationary-phase growth and viability. Taken together, these data demonstrate that VLEC have profound effects on the recovery of S. aureus even after ethanol depletion and delay the transition from primary to secondary metabolite catabolism. These data also suggest that the concentration of ethanol needed for bacteriostatic control of S. aureus is lower than that previously reported.

Structural integrity after cold storage of human epidermal model in hypothermosol: A correlative ultrastructural and fluorescent assay

1994 ◽  
Vol 52 ◽  
pp. 270-271
Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk
Keyword(s):  
Cold Storage ◽  
Structural Integrity ◽  
Culture Media ◽  
Cell Structure ◽  
Natural State ◽  
Sodium Cacodylate ◽  
Ruthenium Tetroxide ◽  
Cacodylate Buffer ◽  
Before And After

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.

Platelet Microtubule Subunit Proteins

1979 ◽  
Vol 42 (05) ◽  
pp. 1630-1633 ◽  
Author(s):  
A G Castle ◽  
N Crawford
Keyword(s):  
Epithelial Cells ◽  
Gel Electrophoresis ◽  
Blood Platelets ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Lens Epithelial Cells ◽  
Molecular Weights ◽  
Kinetics Of ◽  
Microtubular Structures

SummaryBlood platelets contain microtubule proteins (tubulin and HMWs) which can be polymerised “in vitro” to form structures which resemble the microtubules seen in the intact platelet. Platelet tubulin is composed of two non-identical subunits a and p tubulin which have molecular weights around 55,000 but can be resolved in alkaline SDS-polyacrylamide gel electrophoresis. These subunits associate as dimers with sedimentation coefficients of about 5.7 S although it is not known whether the dimer protein is a homo- or hetero-dimer. The dimer tubulin binds the anti-mitotic drug colchicine and the kinetics of this binding are similar to those reported for neurotubulins. Platelet microtubules also contain two HMW proteins which appear to be essential and integral components of the fully assembled microtubule. These proteins have molecular weights greater than 200,000 daltons. Fluorescent labelled antibodies to platelet and brain tubulins stain long filamentous microtubular structures in bovine lens epithelial cells and this pattern of staining is prevented by exposing the cells to conditions known to cause depolymerisation of cell microtubules.

Pertumbuhan Dan Perkembangan Anggrek Dendrobium anosmum Pada Media Kultur In Vitro Dengan Beberapa Konsentrasi Air Kelapa

Agrologia ◽  
2018 ◽  
Vol 1 (1) ◽  
Author(s):  
S. Tuhuteru ◽  
Meity L Hehanussa ◽  
Simon H.T Raharjo
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Water Concentration ◽  
Medium Composition ◽  
Coconut Water ◽  
Orchid Species ◽  
Randomized Design ◽  
Wet Weight ◽  
Completely Randomized Design

Dendrobium anosmum is one of natural orchids in Indonesia. Optimization of medium composition for orchid propagation through in vitro culture is necessary to enhance propagule multiplication capabilities and quality. This study was aimed to study the influence of concentration of coconut water in culture medium on in vitro growth and development of D. anosmum orchid species and to determine the optimal coconut water concentration in culture media.  The experiment were arranged in a Completely Randomized Design with four treatments and eight replications. The treatments consisted of the addition of coconut water with concentrations: 0 ml•l -1 (control), 50 ml•l-1, 100 ml•l-1 and 150 ml•l-1. The results showed that addition of coconut water in culture medium gave different effect on shoot growth and multiplication of D. anosmum orchids.  Coconut water concentration of 100 ml•l-1 was the best concentration for growth and multiplication of D. anosmum orchids, based on both shoots and roots growth, plantlet height and wet weight.

scholarly journals Biological Effects of XyloCore, a Glucose Sparing PD Solution, on Mesothelial Cells: Focus on Mesothelial-Mesenchymal Transition, Inflammation and Angiogenesis

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2282
Author(s):  
Valentina Masola ◽  
Mario Bonomini ◽  
Maurizio Onisto ◽  
Pietro Manuel Ferraro ◽  
Arduino Arduini ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Viability ◽  
Biological Effects ◽  
Membrane Integrity ◽  
Glucose Content ◽  
Mesenchymal Transition ◽  
Low Glucose ◽  
Endothelial To Mesenchymal Transition ◽  
Osmotic Agents

Glucose-based solutions remain the most used osmotic agents in peritoneal dialysis (PD), but unavoidably they contribute to the loss of peritoneal filtration capacity. Here, we evaluated at a molecular level the effects of XyloCore, a new PD solution with a low glucose content, in mesothelial and endothelial cells. Cell viability, integrity of mesothelial and endothelial cell membrane, activation of mesothelial and endothelial to mesenchymal transition programs, inflammation, and angiogenesis were evaluated by several techniques. Results showed that XyloCore preserves mesothelial and endothelial cell viability and membrane integrity. Moreover XyloCore, unlike glucose-based solutions, does not exert pro-fibrotic, -inflammatory, and -angiogenic effects. Overall, the in vitro evidence suggests that XyloCore could represent a potential biocompatible solution promising better outcomes in clinical practice.

Nephrotoxicity Testing In Vitro: The Current Situation

1997 ◽  
Vol 25 (5) ◽  
pp. 497-503
Author(s):  
Jean-Paul Morin ◽  
Marc E. De Broe ◽  
Walter Pfaller ◽  
Gabriele Schmuck
Keyword(s):  
Proximal Tubule ◽  
Culture Media ◽  
Task Force ◽  
Primary Cultures ◽  
Phenotypic Expression ◽  
Transepithelial Transport ◽  
Specific Cell ◽  
Proximal Tubule Cells ◽  
Tubule Cells

An ECVAM task force on nephrotoxicity has been established to advise, in particular, on the follow-up to recommendations made in the ECVAM workshop report on nephrotoxicity testing in vitro. Since this workshop was held, in 1994, there have been several improvements in the techniques used. For example, the duration of renal slice viability, and the maintenance of functional activities in slices, have been improved by using dynamic incubation systems with higher oxygen tensions and more-appropriate cell culture media. Highly differentiated primary cultures of pig, human and rabbit proximal tubule cells have been established by using specific cell isolation procedures and/or selective culture media. To date, the most comparable phenotypic expression and transepithelial transport capacities to proximal tubules in vivo have been obtained with primary cultures of rabbit proximal tubule cells which are grown on bicompartmental supports; in this system, transepithelial substrate gradients are generated and the transepithelial transport of both organic anions and cations is highly active. This in vitro system has been selected by ECVAM for further evaluation and prevalidation. Industrial needs in the area of nephrotoxicity testing have been identified, and recommendations are made at the end of this report concerning possible future initiatives.

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