scholarly journals The impact of seasonal variation on the volatile oil profile of leaves of Severinia buxifolia (Poir.) and its antimicrobial activity

2018 ◽  
Vol 10 (3) ◽  
pp. 56-63 ◽  
Author(s):  
A. Nour Safaa ◽  
A. Abdel Kawy Mostafa ◽  
M. Salama Maha ◽  
S. Hifnawy Mohamed
Keyword(s):  
Antimicrobial Activity ◽  
Seasonal Variation ◽  
Volatile Oil ◽  
The Impact ◽  
Severinia Buxifolia

Chemical Composition and Antimicrobial Activity of Bark and Leaf Extracts of Cupressus sempervirens and Juniperus phoenicea Grown in Al- Jabel Al-Akhdar Region, Libya

2019 ◽  
Vol 9 (4) ◽  
pp. 268-279
Author(s):  
Mohamed E.I. Badawy ◽  
Ibrahim E.A. Kherallah ◽  
Ahmed S.O. Mohareb ◽  
Mohamed. Z.M. Salem ◽  
Hameda A. Yousef
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Sea Level ◽  
Plant Extracts ◽  
Complex Mixture ◽  
Biologically Active ◽  
Cupressus Sempervirens ◽  
Leaf Extracts ◽  
Juniperus Phoenicea ◽  
The Impact

Background:Plant extracts are important products in the world and have been widely used for isolation of important biologically active products. Because of their significant environmental impact, extensive research has been explored to determine the antimicrobial activity of plant extracts.Methods:Acetone extracts of the bark and leaf of Cupressus sempervirens and Juniperus phoenicea, collected from three different altitudes (125, 391, and 851 m high of sea level) at Al- Jabel Al-Akhdar area, Libya were obtained and analyzed by GC/MS. The antimicrobial activity of the extracts was further evaluated against plant bacteria Rhizobium radiobacter, Erwinia carotovora, Rhodococcus fascians and Ralstonia solanacearum and fungus Botrytis cinerea.Results:The impact of the altitude from the sea level on the quantity and chemical constituents of the extracts was investigated. The yield was largely dependent on tree species and the highest yield (6.50%) was obtained with C. sempervirens L bark of altitude III (851 m of the sea level), while the lowest (1.17%) was obtained with the leaf extract of C. sempervirens L from altitude I (125 m). The chemical composition analyzed by GC/MS confirmed that the leaf extracts of C. sempervirens and J. phoenicea contained a complex mixture of monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolic, steroids and phthalates. However, the bark extracts of both trees contained a mixture of sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, phthalates, retinol and steroids. These constituents revealed some variability among the extracts displaying the highest interesting chemotype of totarol (terpenophenolic) in all extracts (14.63-78.19% of the total extract). The extracts displayed a noteworthy antifungal potency with varying degrees of inhibition of growth with EC50 values ranged from 78.50 to 206.90 mg/L. The extracts obtained from the leaves of C. sempervirens showed that the highest inhibitory activity was obtained with the extract of altitude II (391 m) with MIC 565, 510, 380 and 710 mg/L against E. carotovora, R. fascians, and R. radiobacter and R. solanacearum, respectively.Conclusion:Based on antimicrobial activity, raw plant extracts can be a cost-effective way to protect crops from microbial pathogens. Because plant extracts contain several antimicrobial compounds, the development of resistant pathogens can be delayed.

scholarly journals The carbon source-dependent pattern of antimicrobial activity and gene expression in Pseudomonas donghuensis P482

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Matuszewska ◽  
Tomasz Maciąg ◽  
Magdalena Rajewska ◽  
Aldona Wierzbicka ◽  
Sylwia Jafra
Keyword(s):  
Gene Expression ◽  
Antimicrobial Activity ◽  
Carbon Source ◽  
Reference Genes ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Carbon Sources ◽  
Unknown Compound ◽  
Fungal Plant Pathogens ◽  
The Impact

AbstractPseudomonas donghuensis P482 is a tomato rhizosphere isolate with the ability to inhibit growth of bacterial and fungal plant pathogens. Herein, we analysed the impact of the carbon source on the antibacterial activity of P482 and expression of the selected genes of three genomic regions in the P482 genome. These regions are involved in the synthesis of pyoverdine, 7-hydroxytropolone (7-HT) and an unknown compound (“cluster 17”) and are responsible for the antimicrobial activity of P482. We showed that the P482 mutants, defective in these regions, show variations and contrasting patterns of growth inhibition of the target pathogen under given nutritional conditions (with glucose or glycerol as a carbon source). We also selected and validated the reference genes for gene expression studies in P. donghuensis P482. Amongst ten candidate genes, we found gyrB, rpoD and mrdA the most stably expressed. Using selected reference genes in RT-qPCR, we assessed the expression of the genes of interest under minimal medium conditions with glucose or glycerol as carbon sources. Glycerol was shown to negatively affect the expression of genes necessary for 7-HT synthesis. The significance of this finding in the light of the role of nutrient (carbon) availability in biological plant protection is discussed.

scholarly journals Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

2021 ◽  
Author(s):  
Mayara P. Neves ◽  
Pavel Kratina ◽  
Rosilene L. Delariva ◽  
J. Iwan Jones ◽  
Clarice B. Fialho
Keyword(s):  
Seasonal Variation ◽  
Fish Species ◽  
Resource Availability ◽  
Seasonal Changes ◽  
Dry Season ◽  
Diet Overlap ◽  
Isotopic Niche ◽  
Neotropical Streams ◽  
Feeding Plasticity ◽  
The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

Chemical Composition and Antimicrobial Activity of the Volatile Oil fromBaccharis articulate(Lam.) Pers.

2008 ◽  
Vol 20 (4) ◽  
pp. 366-368 ◽  
Author(s):  
Euclésio Simionatto ◽  
Vinicius Ilha ◽  
Anderson S. Mallmann ◽  
Carla Porto ◽  
Ionara I. Dalcol ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Volatile Oil

scholarly journals Preliminary phytochemical screening and susceptibility of bacteria pathogens to whole extract of evolvulus alsinoides (L.)

1970 ◽  
Vol 18 ◽  
pp. 16-20
Author(s):  
BA Omogbai ◽  
FA Eze
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Bacillus Cereus ◽  
Pathogenic Bacteria ◽  
Volatile Oil ◽  
Salmonella Typhi ◽  
Phytochemical Screening ◽  
Evolvulus Alsinoides ◽  
And Staphylococcus Aureus

Context: Plant based antimicrobial represent a vast untapped source for medicines and further exploration of plant antimicrobial neeto occur. Evolvulus alsinoides (L) (Convolvulaceae) is a perennial herb is used in traditional medicine in East Asia, India, Africa and Philippines to cure fever, cough, cold, venereal diseases, azoospermia, adenitis and dementia.   Objective: The objective of this research was to evaluate the antimicrobial activity of the extracts of E. alsinoides on some clinical microbial isolates.   Materials and Methods: The ed thanolic and aqueous extracts of the whole plant (leaves and twigs) were analysed for alkanoids, tannins, glycosides, steroids, flavonoids, saponins, volatile oil and resins. The determination of antibacterial activity was done using the agar well diffusion technique. Pure cultures of pathogenic bacteria such as Bacillus cereus, Staphylococcus aureus, Micrococcus leutus, Klebsiella Pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi were used for antibacterial activity assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).   Results: The ethanolic extract of the plant had MIC values ranging from 16 mg/ml to 512.5 mg/ml. The least MIC was 16mg-ml against Salmonella typhi while Bacillus cereus and Staphylococcus aureus showed the highest MIC of 512.5 mg-ml. In the aqueous extract the MIC ranged between 512.5 to >1025 mg/ml. Salmonella typhi, Micrococcus luteus and Staphylococcus aureus were not inhibited by the water extract. Phytochemical result showed ethanol to be a better solvent for the extraction of the bioactive agents in this plant which include: glycosides, alkaloids, saponins, tannins, flavonoids and volatile oil.   Conclusion: In this study the gram-negative organisms had the lowest MICs and MBCs. This suggests their higher susceptibility to the extract of this plant. On the basis of the result obtained in this investigation it can be concluded that ethanol extract of Evolvulus alsinoides had significant in vitro broad spectrum antimicrobial activity.   Keywords: Evolvulus alsinoides; Phytochemical screening; Antibacterial activity. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8769 JBS 2010; 18(0): 16-20

scholarly journals Effect of Seasonal Variation on Clinical Outcome in Patients with Chronic Conditions: Analysis of the Commonwealth Scientific and Industrial Research Organization (CSIRO) National Telehealth Trial (Preprint)

2017 ◽  
Author(s):  
Ahmadreza Argha ◽  
Andrey Savkin ◽  
Siaw-Teng Liaw ◽  
Branko George Celler
Keyword(s):  
Seasonal Variation ◽  
Length Of Stay ◽  
Clinical Outcome ◽  
Seasonal Variations ◽  
Chronic Conditions ◽  
Hospital Admissions ◽  
Australian Capital Territory ◽  
Home Telemonitoring ◽  
The Impact ◽  
At Home

BACKGROUND Seasonal variation has an impact on the hospitalization rate of patients with a range of cardiovascular diseases, including myocardial infarction and angina. This paper presents findings on the influence of seasonal variation on the results of a recently completed national trial of home telemonitoring of patients with chronic conditions, carried out at five locations along the east coast of Australia. OBJECTIVE The aim is to evaluate the effect of the seasonal timing of hospital admission and length of stay on clinical outcome of a home telemonitoring trial involving patients (age: mean 72.2, SD 9.4 years) with chronic conditions (chronic obstructive pulmonary disease coronary artery disease, hypertensive diseases, congestive heart failure, diabetes, or asthma) and to explore methods of minimizing the influence of seasonal variations in the analysis of the effect of at-home telemonitoring on the number of hospital admissions and length of stay (LOS). METHODS Patients were selected from a hospital list of eligible patients living with a range of chronic conditions. Each test patient was case matched with at least one control patient. A total of 114 test patients and 173 control patients were available in this trial. However, of the 287 patients, we only considered patients who had one or more admissions in the years from 2010 to 2012. Three different groups were analyzed separately because of substantially different climates: (1) Queensland, (2) Australian Capital Territory and Victoria, and (3) Tasmania. Time series data were analyzed using linear regression for a period of 3 years before the intervention to obtain an average seasonal variation pattern. A novel method that can reduce the impact of seasonal variation on the rate of hospitalization and LOS was used in the analysis of the outcome variables of the at-home telemonitoring trial. RESULTS Test patients were monitored for a mean 481 (SD 77) days with 87% (53/61) of patients monitored for more than 12 months. Trends in seasonal variations were obtained from 3 years’ of hospitalization data before intervention for the Queensland, Tasmania, and Australian Capital Territory and Victoria subgroups, respectively. The maximum deviation from baseline trends for LOS was 101.7% (SD 42.2%), 60.6% (SD 36.4%), and 158.3% (SD 68.1%). However, by synchronizing outcomes to the start date of intervention, the impact of seasonal variations was minimized to a maximum of 9.5% (SD 7.7%), thus improving the accuracy of the clinical outcomes reported. CONCLUSIONS Seasonal variations have a significant effect on the rate of hospital admission and LOS in patients with chronic conditions. However, the impact of seasonal variation on clinical outcomes (rate of admissions, number of hospital admissions, and LOS) of at-home telemonitoring can be attenuated by synchronizing the analysis of outcomes to the commencement dates for the telemonitoring of vital signs. CLINICALTRIAL Australian New Zealand Clinical Trial Registry ACTRN12613000635763; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364030&isReview=true (Archived by WebCite at http://www.webcitation.org/ 6xLPv9QDb)

scholarly journals Chemical Composition and in Vitro Antimicrobial Activity of the Volatile Oils from Gliomastix murorum and Pichia guilliermondii, Two Endophytic Fungi in Paris polyphylla var. yunnanensis

2009 ◽  
Vol 4 (11) ◽  
pp. 1934578X0900401 ◽  
Author(s):  
Jianglin Zhao ◽  
Tijiang Shan ◽  
Yongfu Huang ◽  
Xili Liu ◽  
Xiwu Gao ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Endophytic Fungi ◽  
Inhibitory Concentration ◽  
Octadecenoic Acid ◽  
Volatile Oil ◽  
Pichia Guilliermondii ◽  
Volatile Oils ◽  
Paris Polyphylla ◽  
Gliomastix Murorum

Volatile oils were obtained by hydrodistillation from Gliomastix murorum and Pichia guilliermondii, two endophytic fungi isolated from the traditional Chinese medicinal herb Paris polyphylla var. yunnanensis. The oils were analyzed for their chemical composition by gas chromatography-mass spectrometry (GC-MS). Palmitic acid (15.5%), (E)-9-octadecenoic acid (11.6%), 6-pentyl-5,6-dihydropyran-2-one (9.7%), and (7Z,10Z)-7,10- hexadecadienoic acid (8.3%) were the major compounds of the 40 identified components in G. murorum volatile oil. 1,1,3a,7-Tetramethyl-1a,2,3,3a,4,5,6,7b-octahydro-1H-cyclopropa[a]- naphthalene (25.9%), palmitic acid (15.5%), 1-methyl-2,4-di- (prop-1-en-2-yl)-1- vinylcyclohexane (7.9%), (E)-9-octadecenoic acid (7.3%), and (9E,12E)-ethyl-9,12-octadecadienoate (5.2%) were the major compounds of the 27 identified components in P. guilliermondii volatile oil. The in vitro antimicrobial activity of the volatile oils was also investigated to evaluate their efficacy against six bacteria and one phytopathogenic fungus. The minimum inhibitory concentration (MIC) values of the volatile oils against the test bacteria ranged from 0.20 mg/mL to 1.50 mg/mL. One of the most sensitive bacteria was Xanthomonas vesicatoria with an MIC of 0.20 mg/mL and 0.40 mg/mL for G. murorum and P. guilliermondii, respectively. The mean inhibitory concentration (IC50) of the volatile oils against spore germination of Magnaporthe oryzae was 0.84 mg/mL for G. murorum and 1.56 mg/mL for P. guilliermondii. These results indicated that the volatile oils from the endophytic fungi have strong antimicrobial activity and could be a potential source of antimicrobial ingredients.

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