STUDIES ON THE NUTRITION OF PHYTOPHTHORA CRYPTOGEA

1961 ◽  
Vol 7 (1) ◽  
pp. 15-25 ◽  
Author(s):  
D. C. Erwin ◽  
H. Katznelson
Keyword(s):  
Synthetic Medium ◽  
Soluble Starch ◽  
Soil Extract ◽  
Root Extract ◽  
Phytophthora Cryptogea ◽  
Low Concentrations ◽  
Wide Range ◽  
Complete Synthetic Medium ◽  
Minimal Concentration ◽  
Alfalfa Root

Phytophthora cryptogea, cause of a root disease of alfalfa, grew well over a wide range of pH values (5.6–7.2) on a synthetic medium containing sucrose as the carbon source. The fungus also grew well on glucose and soluble starch. L-Asparagine was the most favorable source of nitrogen, but failed to support growth of a variant obtained from a single germinated oospore. Low concentrations of CaCl2∙2H2O stimulated growth of P. cryptogea, P. drcehsleri, P. parasitica, and P. boehmeriae. The minimal concentration of thiamine for growth was between 12 and 25 μg/liter. Soil extract, representing 50% or 90% of the volume of the synthetic medium, did not supply the thiamine requirement or stimulate growth of the fungus. Alfalfa root extract, alone or added to the synthetic medium, not only satisfied the thiamine requirement of the fungus but produced about 30% more mycelial growth than the complete synthetic medium.

Antimicrobial Peptides - Small but Mighty Weapons for Plants to Fight Phytopathogens

2019 ◽  
Vol 26 (10) ◽  
pp. 720-742 ◽  
Author(s):  
Kaushik Das ◽  
Karabi Datta ◽  
Subhasis Karmakar ◽  
Swapan K. Datta
Keyword(s):  
Antimicrobial Peptides ◽  
Durable Resistance ◽  
Defense Responses ◽  
Defense System ◽  
Biotechnological Potential ◽  
Functional Aspects ◽  
Low Concentrations ◽  
Wide Range ◽  
Vital Component ◽  
Pathogen Entry

Antimicrobial Peptides (AMPs) have diverse structures, varied modes of actions, and can inhibit the growth of a wide range of pathogens at low concentrations. Plants are constantly under attack by a wide range of phytopathogens causing massive yield losses worldwide. To combat these pathogens, nature has armed plants with a battery of defense responses including Antimicrobial Peptides (AMPs). These peptides form a vital component of the two-tier plant defense system. They are constitutively expressed as part of the pre-existing first line of defense against pathogen entry. When a pathogen overcomes this barrier, it faces the inducible defense system, which responds to specific molecular or effector patterns by launching an arsenal of defense responses including the production of AMPs. This review emphasizes the structural and functional aspects of different plant-derived AMPs, their homology with AMPs from other organisms, and how their biotechnological potential could generate durable resistance in a wide range of crops against different classes of phytopathogens in an environmentally friendly way without phenotypic cost.

The Influence of Ultra-Low Concentrations of Potassium Anphen on the Bioenergetic Characteristics of Mitochondria

2020 ◽  
Vol 16 (4) ◽  
pp. 537-542
Author(s):  
Zhigacheva Irina ◽  
Volodkin Aleksandr ◽  
Rasulov Maksud
Keyword(s):  
Functional State ◽  
Membrane Lipids ◽  
Biological Effects ◽  
Dose Dependence ◽  
Stress Factors ◽  
Mitochondrial Membranes ◽  
Oxidation Rates ◽  
Pea Seedlings ◽  
Low Concentrations ◽  
Wide Range

Background: One of the main sources of ROS in stress conditions is the mitochondria. Excessive generation of ROS leads to oxidation of thiol groups of proteins, peroxidation of membrane lipids and swelling of the mitochondria. In this regard, there is a need to search for preparationsadaptogens that increase the body's resistance to stress factors. Perhaps, antioxidants can serve as such adaptogens. This work aims at studying the effect of antioxidant; the potassium anphen in a wide range of concentrations on the functional state of 6 day etiolated pea seedlings mitochondria (Pisum sativum L). Methods: The functional state of mitochondria was studied per rates of mitochondria respiration, by the level of lipid peroxidation and study of fatty acid composition of mitochondrial membranes by chromatography technique. Results: Potassium anphen in concentrations of 10-5 - 10-8 M and 10-13-10-16 prevented the activation of LPO in the mitochondrial membranes of pea seedlings, increased the oxidation rates of NAD-dependent substrates and succinate in the respiratory chain of mitochondria that probably pointed to the anti-stress properties of the drug. Indeed, the treatment of pea seeds with the preparation in concentrations of 10-13 M prevented the inhibition of growth of seedlings in conditions of water deficiency. Conclusion: It is assumed that the dose dependence of the biological effects of potassium anphen and the manifestation of these effects in ultra-low concentrations are due to its ability in water solutions to form a hydrate containing molecular ensembles (structures).

scholarly journals Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review

2021 ◽  
Vol 13 (15) ◽  
pp. 8620
Author(s):  
Sanaz Salehi ◽  
Kourosh Abdollahi ◽  
Reza Panahi ◽  
Nejat Rahmanian ◽  
Mozaffar Shakeri ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Operating Conditions ◽  
Phenolic Pollutants ◽  
Petroleum Refinery Wastewater ◽  
Start Up ◽  
Low Concentrations ◽  
Effective Removal ◽  
Wide Range ◽  
Loading Effects ◽  
Spent Caustic

Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.

scholarly journals In Vitro Synergistic Interactions of Isavuconazole and Echinocandins against Candida auris

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 355
Author(s):  
Unai Caballero ◽  
Sarah Kim ◽  
Elena Eraso ◽  
Guillermo Quindós ◽  
Valvanera Vozmediano ◽  
...  
Keyword(s):  
Interaction Model ◽  
Antifungal Drugs ◽  
Health Concern ◽  
Candida Auris ◽  
Fungistatic Activity ◽  
Drug Concentrations ◽  
Low Concentrations ◽  
Wide Range ◽  
Time Kill

Candida auris is an emergent fungal pathogen that causes severe infectious outbreaks globally. The public health concern when dealing with this pathogen is mainly due to reduced susceptibility to current antifungal drugs. A valuable alternative to overcome this problem is to investigate the efficacy of combination therapy. The aim of this study was to determine the in vitro interactions of isavuconazole with echinocandins against C. auris. Interactions were determined using a checkerboard method, and absorbance data were analyzed with different approaches: the fractional inhibitory concentration index (FICI), Greco universal response surface approach, and Bliss interaction model. All models were in accordance and showed that combinations of isavuconazole with echinocandins resulted in an overall synergistic interaction. A wide range of concentrations within the therapeutic range were selected to perform time-kill curves. These confirmed that isavuconazole–echinocandin combinations were more effective than monotherapy regimens. Synergism and fungistatic activity were achieved with combinations that included isavuconazole in low concentrations (≥0.125 mg/L) and ≥1 mg/L of echinocandin. Time-kill curves revealed that once synergy was achieved, combinations of higher drug concentrations did not improve the antifungal activity. This work launches promising results regarding the combination of isavuconazole with echinocandins for the treatment of C. auris infections.

scholarly journals In vitro antimicrobial activity of the organic extract of Cladonia substellata Vainio and usnic acid against Staphylococcus spp. obtained from cats and dogs

2017 ◽  
Vol 37 (4) ◽  
pp. 368-378 ◽  
Author(s):  
Jusciêne B. Moura ◽  
Agueda C. de Vargas ◽  
Gisele V. Gouveia ◽  
João J. de S. Gouveia ◽  
Juracy C. Ramos-Júnior ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activities ◽  
Meca Gene ◽  
Usnic Acid ◽  
Organic Extract ◽  
In Vitro Antimicrobial Activity ◽  
Low Concentrations ◽  
Wide Range ◽  
Staphylococcus Spp

ABSTRACT: Cladonia substellata Vainio is a lichen found in different regions of the world, including the Northeast of Brazil. It contains several secondary metabolites with biological activity, including usnic acid, which has exhibited a wide range of biological activities. The aim of this study was to evaluate the in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid. Initially, Staphylococcus spp., derived from samples of skin and ears of dogs and cats with suspected pyoderma and otitis, were isolated and analyzed. In antimicrobial susceptibility testing against Staphylococcus spp., 77% (105/136) of the isolates were resistant to the antimicrobials tested. In the assessment of biofilm production, 83% (113/136) were classified as producing biofilm. In genetic characterization, 32% (44/136) were positive for blaZ, no isolate (0/136) was positive for the mecA gene, and 2% (3/136) were positive for the icaD gene. The in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid against Staphylococcus spp. ranged from 0.25mg/mL to 0.0019mg/mL, inhibiting bacterial growth at low concentrations. The substances were more effective against biofilm-producing bacteria (0.65mg/mL-0.42mg/mL) when compared to non-biofilm producing bacteria (2.52mg/mL-2.71mg/mL). Usnic acid and the organic extract of C. substellata can be effective in the treatment of pyoderma and otitis in dogs and cats caused by Staphylococcus spp.

scholarly journals Gelation or molecular recognition; is the bis-(α,β-dihydroxy ester)s motif an omnigelator?

2010 ◽  
Vol 6 ◽  
pp. 1079-1088 ◽  
Author(s):  
Peter C Griffiths ◽  
David W Knight ◽  
Ian R Morgan ◽  
Amy Ford ◽  
James Brown ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Neutron Scattering ◽  
Spin Echo ◽  
Inelastic Neutron ◽  
Gelation Mechanism ◽  
Regular Structures ◽  
Low Concentrations ◽  
Wide Range ◽  
History Of ◽  
Selection Of

Understanding the gelation of liquids by low molecular weight solutes at low concentrations gives an insight into many molecular recognition phenomena and also offers a simple route to modifying the physical properties of the liquid. Bis-(α,β-dihydroxy ester)s are shown here to gel thermoreversibly a wide range of solvents, raising interesting questions as to the mechanism of gelation. At gelator concentrations of 5–50 mg ml−1, gels were successfully formed in acetone, ethanol/water mixtures, toluene, cyclohexane and chloroform (the latter, albeit at a higher gelator concentration). A range of neutron techniques – in particular small-angle neutron scattering (SANS) – have been employed to probe the structure of a selection of these gels. The universality of gelation in a range of solvent types suggests the gelation mechanism is a feature of the bis-(α,β-dihydroxy ester) motif, with SANS demonstrating the presence of regular structures in the 30–40 Å range. A correlation between the apparent rodlike character of the structures formed and the polarity of the solvent is evident. Preliminary spin-echo neutron scattering studies (SESANS) indicated the absence of any larger scale structures. Inelastic neutron spectroscopy (INS) studies demonstrated that the solvent is largely unaffected by gelation, but does reveal insights into the thermal history of the samples. Further neutron studies of this kind (particularly SESANS and INS) are warranted, and it is hoped that this work will stimulate others to pursue this line of research.

THE EFFECT OF CERTAIN ELEMENTS, WITH EMPHASIS ON NITROGEN, ON THE PRODUCTION OF PERITHECIA OF VENTURIA INAEQUALIS (CKE.) WINT.

1961 ◽  
Vol 39 (4) ◽  
pp. 731-738 ◽  
Author(s):  
R. G. Ross
Keyword(s):  
Venturia Inaequalis ◽  
Synthetic Medium ◽  
Low Concentrations ◽  
Nitrate Salts ◽  
Nitrogen Concentrations ◽  
High Concentrations

Various elements were tested for their effect on the formation of perithecia of Venturia inaequalis. Apart from nitrogen the elements tested had little effect on the formation of perithecia except at relatively high concentrations. Perithecia did not form in media containing low concentrations of nitrogen and this was influenced by the source of nitrogen and by the cation present in nitrate salts. Perithecial initials developed in higher nitrogen concentrations than perithecia. Nitrogen added 9 weeks after mating of two lines of the fungus prevented the formation of perithecia.Results were difficult to reproduce in a potato-dextrose apple leaf decoction medium but reproducible results were obtained in a synthetic medium.

Effects of polymethoxylated flavone metabolites on apoB100 secretion and MTP activity in Huh7.5 cells

2021 ◽  
Vol 18 ◽  
Author(s):  
Danielle R. Gonçalves ◽  
Thais B. Cesar ◽  
John A. Manthey ◽  
Paulo I. Costa
Keyword(s):  
Lipid Synthesis ◽  
Dependent Manner ◽  
Transfer Protein ◽  
Low Concentrations ◽  
Wide Range ◽  
Cell Assays ◽  
Polymethoxylated Flavones ◽  
High Concentrations

Background: Citrus polymethoxylated flavones (PMFs) reduce the synthesis of liver lipoproteins in animal and in vitro cell assays, but few studies have evaluated the direct effects of their metabolites on this highly regulated process. Objective: To investigate the effects of representative metabolites of PMF on the secretion of liver lipoproteins using the mammalian cell Huh7.5. Method: In this study, the influences of three PMFs and five previously isolated PMF metabolites on hepatic apoB-100 secretion and microsomal transfer protein (MTP) activity were evaluated. Tangeretin (TAN), nobiletin (NOB) and 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF), and their glucuronides (TAN-Gluc, NOB-Gluc and HMF-Gluc) and oxidatively demethylated metabolites (TAN-OH, NOB-OH, HMF-OH) were incubated with Huh7.5 cells to measure their inhibitory effects on lipid synthesis. Results: The results showed that TAN, HMF and TAN-OH reduced the secretion of apoB-100 in a dose-dependent manner, while NOB and the other tested metabolites showed no inhibition. MTP activity in the Huh7.5 cells was significantly reduced in the presence of low concentrations of TAN, and in high concentrations of NOB-OH. This study also showed that PMFs and PMF metabolites produced a wide range of effects on apoB-100 secretion and MTP activity. Conclusion: The results suggest that while PMFs and their metabolites control dyslipidemia in vivo, the inhibition of MTP activity cannot be the only pathway influenced by these compounds.

Plasma leptin concentration and its interrelation with some blood metabolites, metabolic hormones and the resumption of cyclic ovarian function in postpartum dairy cows supplemented with monensin or inert fat in feed

2001 ◽  
Vol 26 (2) ◽  
pp. 405-409 ◽  
Author(s):  
Gy. Huszenicza ◽  
M. Kulcsar ◽  
J. A. Nikolic ◽  
J. Schmidt ◽  
P. Korodi ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Low Dose ◽  
Ovarian Function ◽  
Metabolic Hormones ◽  
Delayed Onset ◽  
Wide Range ◽  
Significant Difference ◽  
Minimal Concentration ◽  
Plasma Leptin ◽  
Ovarian Cyclicity

AbstractThe postpartum changes in plasma leptin levels of dairy cows ovulated within 35 days after calving were compared to of those with delayed onset of cyclicity in two experiments. The cows were sampled for leptin, insulin, IGF-1, thyroid hormones (T4, T3, rT3), Cortisol and also for some metabolites (glucose, NEFA, BHB and TCH) on day 1-3 after calving and again four times 7 days apart (Exp. 1), or in weeks 1, 2, 3, 5 and 10 postpartum (Exp. 2). In Exp. 1 also the standard low dose ACTH-induced Cortisol response and TRH-stimulated T4/T3 responses were determined on days 1-3 and 28-35. In cows of Exp. 1 the leptin level varied within a wide range with a mean of about 4 ng/ml HE in the first samples. Up to week 5 it remained unchanged in cows ovulated within day 35 but reduced in those with delayed onset of cyclicity, resulting in significant difference between the two group means.In cows of Exp. 2 the week 1 leptin levels were lower and less variable than that of Exp. 1. In weeks 2 and 3 a slightly increasing tendency of leptin pattern was seen in cows resuming their ovarian cyclicity within 35 days whereas in those with delayed onset of cyclicity the leptin level remained unchanged. Up to week 5 this tendency resulted in exactly the same leptin values as seen in Exp. 1 with significant differences between the group means in both of the weeks 5 and 10. It was concluded that the plasma leptin concentration in postpartum dairy cows may interfere with resumption of cyclic ovarian function, but its influence may be only permissive (e.g. a minimal concentration above a supposed threshold seems to be the prerequisite of the onset of cyclicity)

scholarly journals Geochemical Behavior of Uranium and Radon in Groundwater of Jurassic Granite Area, Icheon, Middle Korea

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1278 ◽  
Author(s):  
Byong Wook Cho ◽  
Chang Oh Choo
Keyword(s):  
Standard Deviation ◽  
Environmental Protection Agency ◽  
Maximum Contaminant Level ◽  
Contaminant Level ◽  
Low Concentrations ◽  
Wide Range ◽  
The Us ◽  
Us Epa ◽  
Independent Behavior ◽  
Radon Concentrations

Uranium concentrations (a total of 82 samples) in groundwater in Icheon, middle Korea, showed a wide range from 0.02 to 1640 μg/L with a mean of 56.77 μg/L, a median of 3.03 μg/L, and a standard deviation of 228.63 μg/L. Most groundwater samples had quite low concentrations: 32.9% were below 1 μg/L, while 15.9% exceeded 30 μg/L, the maximum contaminant level (MCL) of the US EPA (Environmental Protection Agency). Radon concentrations also ranged widely from 1.48 to 865.8 Bq/L. Although the standard deviation of radon was large (151.8 Bq/L), the mean was 211.29 Bq/L and the median was 176.86 Bq/L. Overall, 64.6% of the samples exceeded the alternative maximum contaminant level (AMCL) of the US EPA (148 Bq/L). According to statistical analyses, there was no close correlations between uranium and radon, but there were correlations between uranium and redox potential (Eh) (−0.54), dissolved oxygen (DO) (−0.50), HCO3− (0.45), Sr (0.65), and SiO2 (−0.44). Radon showed independent behavior with respect to most components in groundwater. Uranium concentrations in groundwater increased with increasing water–rock interactions. Anomalously high uranium and radon concentrations in groundwater are preferentially localized in granite areas and spatial distributions are remarkably heterogeneous.

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