Effects of certain cations on the formation and infectivity of Phytophthora zoospores. 2. Effects of copper, boron, cobalt, manganese, molybdenum, and zinc ions

1977 ◽  
Vol 23 (8) ◽  
pp. 1002-1010 ◽  
Author(s):  
D. M. Halsall
Keyword(s):  
Mycelial Growth ◽  
Copper Ions ◽  
Protective Action ◽  
Fungal Species ◽  
Zinc Ions ◽  
Dilute Solution ◽  
Infection Period ◽  
Total Inhibition ◽  
Pot Trials ◽  
Calcium Magnesium

The effects of copper, boron, cobalt, manganese, molybdenum, and zinc on the production of zoosporangia by P. cinnamomi and P. drechsleri in the presence of favourable concentrations of calcium, magnesium, potassium, and iron were investigated. Copper ions were the most effective in reducing the numbers of zoosporangia formed by both fungal species. Molybdenum was also slightly inhibitory.Total inhibition of mycelial growth occurred between 1 and 5 × 10−5 M Cu2+ whereas total inhibition of sporangial formation occurred between 1 and5 × 10−7 M Cu2+. At copper concentrations between 10−5 M and 5 × 10−7 M, many P. drechsleri zoosporangia were abnormal in appearance and nonviable.Infection of eucalypt cotyledons by P. drechsleri zoospores was inhibited by 10−6 M Cu2+ but this inhibition was reversed by EDTA (10−4 M). There was no evidence for interaction between Cu2+ and Ca2+, Mg2+, K+, or Fe2+ present in the solutions used in the axenic production of zoospores. Preliminary pot trials indicated that CuSO4 had a protective action for safflower seedlings to infection by P. drechsleri when CuSO4 was applied as a dilute solution over the infection period.

scholarly journals The Efficacy of Whole Oyster Shells for Removing Copper, Zinc, Chromium, and Cadmium Heavy Metal Ions from Stormwater

2021 ◽  
Vol 13 (8) ◽  
pp. 4184
Author(s):  
Zhiying Xu ◽  
Caterina Valeo ◽  
Angus Chu ◽  
Yao Zhao
Keyword(s):  
Surface Area ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Exposure Time ◽  
Food Waste ◽  
Positive Relationship ◽  
Copper Ions ◽  
Zinc Ions ◽  
Cadmium Ions ◽  
Initial Concentration

This research investigates the use of a common food waste product for removing four different types of metals typically found in stormwater. Whole, unprocessed oyster shells are explored for use in stormwater management infrastructure that addresses water quality concerns. The role of the shells’ surface area, exposure time, and the solution’s initial concentration on the removal efficiency were examined. Beaker scale experimental results demonstrated very good efficiency by the oyster shells for removing copper ions (80–95%), cadmium ions (50–90%), and zinc ions (30–80%) but the shells were not as effective in removing hexavalent chromium (20–60%). There was a positive relationship between initial concentration and removal efficiency for copper and zinc ions, a negative relationship for hexavalent chromium, and no relationship was found for cadmium ions. There was also a positive relationship between surface area and removal efficiency, and exposure time and removal efficiency. However, after a certain exposure time, the increase in removal efficiency was negligible and desorption was occasionally observed. A mid-scale experiment to mimic real-world conditions was conducted in which continuous inflow based on a 6-h design storm was applied to 2.7 kg of whole, unprocessed oyster shells. The shells provided an 86% and an 84% removal efficiency of cadmium and copper ions, respectively, in one day of hydraulic retention time. No removal was observed for hexavalent chromium, and zinc ion removal was only observed after initial leaching. This work has significant implications for sustainable stormwater infrastructure design using a material commonly found in municipal food waste.

Peanut Web Blotch: I. Cultural Characteristics and Identity of Causal Fungus1

1984 ◽  
Vol 11 (2) ◽  
pp. 109-114 ◽  
Author(s):  
R. A. Taber ◽  
R. E. Pettit ◽  
G. L. Philley
Keyword(s):  
South Africa ◽  
Cultural Studies ◽  
Mycelial Growth ◽  
Fungal Species ◽  
Optimum Temperature ◽  
Cultural Characteristics ◽  
Foliar Disease ◽  
The Usa

Abstract A foliar disease of peanuts, previously unreported in the USA, was found in Texas in 1972. The pathogen was identified as a species of Ascochyta. Further cultural studies have revealed this fungus to be Phoma arachidicola Marasas, Pauer, and Boerema. Pycnidia form profusely at 20 C and 25 C. Pycnidiospores are borne on short pycnidiosphores and are predominantly one-celled in culture. Spores produced in pycnidia on infected leaflets become 1 septate. Large 1-septate spores, as well as an occasional 2-septate spore, may form in culture. Optimum temperature for mycelial growth in 20 C; little or no growth occurs at 5 C or above 30 C. The teleomorphic state develops in the field on fallen leaflets and can be induced to form in the laboratory on sterilized peanut leaflets between 15 and 20 C. Cultures derived from single ascospores form pseudothecia. Pycnidiospores, ascospores, and chlamydospores are all infective units. Because this fungus produces hyaline ascospores and pseudoparaphyses, it has been transferred to the genus Didymella as Didymella arachidicola (Choch.) comb. nov. Comparisons with 15 isolates causing web blotch of peanut in the USA, Argentina, and South Africa indicate that web blotch symptoms are produced by the same fungal species.

scholarly journals Purification and properties of a phytase from Candida melibiosica 2491

2018 ◽  
Author(s):  
Danail Georgiev ◽  
Georgi Dobrev ◽  
Stefan Shilev
Keyword(s):  
Molecular Weight ◽  
Copper Ions ◽  
Phytase Activity ◽  
Gel Chromatography ◽  
Experimental Conditions ◽  
Cobalt Ions ◽  
Whole Cells ◽  
Inhibition Effect ◽  
Total Inhibition ◽  
Purification And Properties

Aim: To characterize the enzyme phytase produced by phytase-active Candida melibiosica 2491 for subsecuent use in feed industry. Methods: C. melibiosica 2491 had been selected among 118 strains as the most productive strain of phytase. In present study, the enzyme was first purified through electrophoresis grade in four steps: precipitation with organic solvent, ultrafiltration, gel chromatography and Denaturing gel electrophoresis (SDS–PAGE). Results: Higher levels of purification were obtained using ethanol. The gel chromatography showed an elution maximum at 11-12 fractions that characterize the corresponding one as high-molecular weight phytase. The purification level was found to be 19.5 folds with specific enzyme activity of 2.75 U/mg protein and yield – 19.64 %. Furthermore, the molecular weight of purified phytase was estimated to 35.9 кDa, with optimum of pH – at 4.5 and optimum of temperature at 55 °C. Maximum phytase activity in case of whole cells was found at 50 оС, which was less than using the purified enzyme. It was activated through 5 mM of Ba2+, 10 mM of Mn2+ and K+ ions. Total inhibition effect was achieved from Fe3+, Hg2+ and Zn2+. Copper ions (Cu2+) in concentrations at 5 mM conducted to partial inhibition effect, but at 10 mM the phytase activity was equal to zero. Low inhibition effect was determined in case of cobalt ions (Co2+) at concentrations of 10 mM. The phytase displayed broad sub­strate specificity and the Km for phytate was estimated to be 0.21 mM under the experimental conditions, while Vmax – 19.9 µМ/ml. Conclusion: Although the phytase produced by C. melibiosica 2491 is a promising enzyme to be used successfully in feed production, more investigations are needed to ensure its advantages.

scholarly journals In vitro fungitoxic potential of Lippia gracilis (Schauer) essential oil against phytopathogens

2020 ◽  
pp. 667-674
Author(s):  
Kevison Romulo da Silva França ◽  
Flavia Mota de Figueredo Alves ◽  
Tiago Silva Lima ◽  
Alda Leaby dos Santos Xavier ◽  
Plínio Tércio Medeiros de Azevedo ◽  
...  
Keyword(s):  
Essential Oil ◽  
Mycelial Growth ◽  
Fungal Growth ◽  
Fungal Species ◽  
Phytopathogenic Fungi ◽  
Negative Control ◽  
Growth Speed ◽  
Randomized Design

This study evaluates the in vitro effects of Lippia gracilis essential oil on the mycelial growth of phytopathogenic fungi. Experiments were carried out using a completely randomized design to assess the effects of eight treatments. Five replicates were evaluated for each experimental group. The essential oil was incorporated into the potato dextrose culture medium and poured into Petri dishes. Treatments were comprised of different concentrations of the oil (0.0125, 0.025, 0.05, 0.1, and 0.2%), a negative control (0.0%), and two positive controls (commercial fungicides). The plates were inoculated with fungi including Colletotrichum gloeosporioides, C. musae, C. fructicola, C. asianum, Alternaria alternata, A. brassicicola, Fusarium solani, F. oxysporum f. sp. cubense, and Lasiodiplodia theobromae and were incubated for seven days at 27 ± 2°C. The following variables were measured to verify the differences observed among treatments: percentage of mycelial growth inhibition and index of mycelial growth speed. All concentrations of L. gracilis oil inhibited the mycelial growth of the fungal species evaluated. The complete inhibition was observed between concentrations of 0.0125 and 0.1%. Treatment with oil inhibited fungal growth with similar, or even greater, efficiency than commercial fungicides.. We recommend the development of in vivo tests to verify whether L. gracilis essential oil can protect against fungal disease in live plants.

Reaction kinetics in replacement of zinc ions by copper ions in complexes with cyclic and noncyclic tetramines

1985 ◽  
Vol 21 (2) ◽  
pp. 168-174
Author(s):  
K. B. Yatsimirskii ◽  
V. V. Pavlishchuk ◽  
E. V. Rybak-Akimova
Keyword(s):  
Reaction Kinetics ◽  
Copper Ions ◽  
Zinc Ions

Equilibrium and Kinetic Studies on Removal of Binary Metal Ions Using Immobilized Saccharomyces cerevisiae

2014 ◽  
Vol 661 ◽  
pp. 39-44
Author(s):  
Nur Khalida Adibah Md Rodzi ◽  
Senusi Faraziehan ◽  
Alrozi Rasyidah
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metal Ions ◽  
Copper Ions ◽  
Binding Capacity ◽  
Kinetic Studies ◽  
Suitable Model ◽  
Zinc Ions ◽  
Copper And Zinc ◽  
Maximum Sorption ◽  
Pseudo Second Order

In this study, biosorption of copper and zinc ions on Baker’s yeast, Saccharomyces Cerevisiae was investigated. The data of batch experiments was used to perform equilibrium and kinetic studies. The experimental results were fitted well to the Langmuir and Freundlich model isotherms. According to the parameters of Langmuir isotherm, the maximum biosorption capacities of copper and zinc ions onto immobilized yeast were 5.408mg/g and 1.479mg/g at 293 Kfor the treated beads. Competitive biosorption of two metal ions was investigated in terms of maximum sorption quantity. The binding capacity for copper ions is more than the zinc ions for both untreated and treated immobilized yeast.While, for the kinetic studies, the pseudo second order model was found the most suitable model for the present systems.

scholarly journals Inhibition of hemolytic activity of Streptococcus pyogenes in mechanisms of antibacterial action of zinc ions

2019 ◽  
pp. 16-23
Author(s):  
S. B. Cheknev ◽  
E. I. Vostrova ◽  
M. A. Sarycheva ◽  
A. V. Vostrov
Keyword(s):  
Growth Inhibition ◽  
Streptococcus Pyogenes ◽  
Hemolytic Activity ◽  
Inhibitory Action ◽  
Bacterial Culture ◽  
Copper Ions ◽  
Zinc Ions ◽  
Bacterial Cells ◽  
Bacterial Cultures ◽  
Culture Growth

Aim. The work was performed with the purpose to study a hemolytic activity in the culture of S.pyogenes under the inhibitory action of millimolar concentrations of zinc ions.Materials and methods. Suspensions of S.pyogenes bacteria which contained 108 CFU/ml were sown by the lawns into the standard Petri dishes coated with the supplemented Blood Nutrient Agar. 30 min later the salt solutions of zinc or copper which contained the metals at the concentrations ranged between 5 x 10-3 M to 5 x 10-1 M were added by the 5 μl drops on the surfaces of the lawns with use of 36-channel stamp replicator. Then the dishes with bacterial cultures were incubated for 24 hrs at 37°C followed by measuring diameter of the area of culture growth inhibition and of the area of inhibition of hemolysis. The study was performed with use of controls towards measuring the state of bacterial cells obtained from different zones of the areas.Results. In presence of the zinc ions concentrations ranged between 50 to 500 mM the area of the growth inhibition of S.pyogenes was surrounded on the lawn of the bacterial culture by the area of the inhibition of hemolysis where the growth inhibition of S.pyogenes was not registered. Copper ions did not form such an area of the hemolysis inhibition.Conclusion. Inhibitory action of zinc ions on the hemolytic S.pyogenes activity in the culture seems to be specific and reversible, and is discussed in a context of the antivirulent zinc ions properties.

scholarly journals Pro-Oxidant Activity of an ALS-Linked SOD1 Mutant in Zn-Deficient Form

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3600
Author(s):  
Chise Nagao ◽  
Kunisato Kuroi ◽  
Taiyu Wakabayashi ◽  
Takakazu Nakabayashi
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Copper Ions ◽  
Zinc Ion ◽  
Zinc Ions ◽  
Oxygen Species ◽  
Oxidative Property ◽  
Sod1 Mutant ◽  
Lateral Sclerosis ◽  
In Cells

Cu, Zn superoxide dismutase (SOD1) is a representative antioxidant enzyme that catalyzes dismutation of reactive oxygen species in cells. However, (E,E)-SOD1 mutants in which both copper and zinc ions were deleted exhibit pro-oxidant activity, contrary to their antioxidant nature, at physiological temperatures, following denaturation and subsequent recombination of Cu2+. This oxidative property is likely related to the pathogenesis of amyotrophic lateral sclerosis (ALS); however, the mechanism by which Cu2+ re-binds to the denatured (E,E)-SOD1 has not been elucidated, since the concentration of free copper ions in cells is almost zero. In this study, we prepared the (Cu,E) form in which only a zinc ion was deleted using ALS-linked mutant H43R (His43→Arg) and found that (Cu,E)-H43R showed an increase in the pro-oxidant activity even at physiological temperature. The increase in the pro-oxidant activity of (Cu,E)-H43R was also observed in solution mimicking intracellular environment and at high temperature. These results suggest that the zinc-deficient (Cu,E) form can contribute to oxidative stress in cells, and that the formation of (E,E)-SOD1 together with the subsequent Cu2+ rebinding is not necessary for the acquisition of the pro-oxidant activity.

scholarly journals Baseline Sensitivities of Fungal Pathogens of Fruit and Foliage of Citrus to Azoxystrobin, Pyraclostrobin, and Fenbuconazole

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1186-1194 ◽  
Author(s):  
S. N. Mondal ◽  
Alka Bhatia ◽  
Turksen Shilts ◽  
L. W. Timmer
Keyword(s):  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Fungal Species ◽  
Brown Spot ◽  
Colletotrichum Acutatum ◽  
Fungicide Sensitivity ◽  
Fruit Drop ◽  
Coefficients Of Variation ◽  
Foliar Pathogens

The baseline sensitivities for mycelial growth of foliar fungal pathogens of citrus, Colletotrichum acutatum, Alternaria alternata, Elsinoe fawcettii, Diaporthe citri, and Mycosphaerella citri, the causal agents of postbloom fruit drop, brown spot of tangerine, citrus scab, melanose, and greasy spot, respectively, were determined in vitro for azoxystrobin, pyraclostrobin, and fenbuconazole. The effective dose to reduce growth by 50% (ED50 values) was determined for each pathogen-fungicide combination using five isolates from different citrus areas of Florida and eight fungicide concentrations. A discriminatory dose for each combination was selected near the ED50, and the range of sensitivity of 50 to 62 isolates of each fungal species was determined. The effect of salicylhydroxamic acid (SHAM) on the sensitivity of the five fungal species to azoxystrobin and pyraclostrobin was determined. Since mycelial growth of A. alternata was insensitive to azoxystrobin, the effect of that fungicide with and without SHAM on spore germination was assessed. The ED50 values for most fungal pathogens of citrus were relatively high compared with foliar pathogens of other tree crops. Values for azoxystrobin ranged from a low of 0.06 μg/ml with E. fawcettii to a high of >100 μg/ml with A. alternata. With pyraclostrobin, the values ranged from a low of 0.019 μg/ml with D. citri to a high of 0.87 μg/ml with A. alternata. With fenbuconazole, the lowest ED50 value was 0.21 μg/ml with M. citri and the highest was 1.01 μg/ml with C. acutatum, but A. alternata and D. citri were not tested. SHAM was inhibitory to all species and reduced growth of D. citri greatly. Inclusion of SHAM in the medium did not greatly affect the sensitivity of mycelial growth of these fungi to azoxystrobin or pyraclostrobin, nor did it affect the ED50 values for conidial germination of A. alternata. The coefficients of variation for the sensitivity of 50 to 62 isolates of each species to these fungi ranged from 7.3% with the pyraclostrobin-C. acutatum combination to a high of 55.0% with the fenbuconazole- M. citri combination. Discriminatory doses have been established for these pathogen- fungicide combinations that should be useful for detecting major shifts in fungicide sensitivity.

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