scholarly journals Biological Activities of Heteropyxis natalensis Against Micro-Organisms Involved in Oral Infections

2018 ◽  
Vol 9 ◽  
Author(s):  
Cynthia J. Henley-Smith ◽  
Francien S. Botha ◽  
Ahmed A. Hussein ◽  
Mpumelelo Nkomo ◽  
Debra Meyer ◽  
...  
Keyword(s):  
Biological Activities ◽  
Oral Infections ◽  
Micro Organisms

A study of the fauna of poultry deep litter

1963 ◽  
Vol 60 (2) ◽  
pp. 251-257 ◽  
Author(s):  
A. J. Byng
Keyword(s):  
World War Ii ◽  
Biological Activities ◽  
World War ◽  
Proper Functioning ◽  
Micro Organisms

The ‘built-up or deep’ litter system for housing poultry came into use in America during World War II, when labour and materials were restricted. It consists of recently used Utter, at least 6 in. in depth, containing micro-organisms which produce beneficial heating, synthesizing and sanitizing effects (Halbrook, Winter & Sutton, 1951; Kennard & Chamberlain, 1951). Four requirements have been laid down by Bott, Ferguson, Berkland & Winter (1952) for proper functioning of deep litter; they are:(1) The depth of the litter must be greater than 6 in. to ensure the absorption of fresh dropping and for effective chemical and biological activities.

scholarly journals Isolation of Secondary Metabolites from Leucas aspera and Investigation of Biological Activity

2020 ◽  
Vol 68 (1) ◽  
pp. 101-104
Author(s):  
Md Selim Aktar Reza ◽  
Md Hasanur Rahman ◽  
Tofail Ahmad Chowdhury
Keyword(s):  
Secondary Metabolites ◽  
Methanol Extract ◽  
Biological Activities ◽  
Zone Of Inhibition ◽  
Methanol Fraction ◽  
Leucas Aspera ◽  
Total Antioxidant ◽  
Micro Organisms ◽  
Crude Methanol Extract ◽  
Sample Inhibition

Leucas aspera plant was subjected to isolation of secondary metabolites and screening of their biological activities. Four compounds, stigmasterol, lupeol, β-sitosterol and menthol, were isolated from methanol extract. Sixteen different micro-organisms were used for investigating antimicrobial activity of the different extracts of L. aspera where noteworthy zone of inhibition was observed against Gram positive B. subtilis and S. aureus, B. megaterium and Gram negative S. paratyphi, S. typhi, V. mimicus, S. dysenteriae and V. cholera. In brine shrimp lethality bioassay, the highest lethality was showed by crude methanol extract having LC50 values of 4.07μg/mL. The total antioxidant capacity of crude methanol fraction was found to be 59.40 mg/g of plant extract which was maximum comparing with other fractions. No significant cytotoxicity was observed on both HeLa and Vero cell at 1mg/mL sample inhibition. Dhaka Univ. J. Sci. 68(1): 101-104, 2020 (January)

Growing preferences towards Analogue based Drug Discovery

2020 ◽  
Vol 21 ◽  
Author(s):  
Mehak Dangi ◽  
Alka Khichi ◽  
Ritu Jakhar ◽  
Anil Kumar Chhilar
Keyword(s):  
Drug Design ◽  
Biological Activities ◽  
New Drugs ◽  
Antimicrobial Drugs ◽  
Structure Based Drug Design ◽  
Computational Screening ◽  
Tools And Techniques ◽  
Micro Organisms ◽  
Anti Fungal

Background: The major concern of today's time is the developing resistance in the most of the clinically derived pathogenic micro-organisms for the available drugs through several mechanisms. So, there is an acute need to develop novel molecules with drug like properties that can be effective against the otherwise resistant micro-organisms. Methods : New drugs can be developed using several methods like structure based drug design, ligand based drug design or by developing analogues of the available drugs to improve their effect further. But the smartness is to opt for the techniques that involve lower expenditure, lower failure rates and faster discovery rates. Results: Analogue based drug design (ABDD) is one such technique that researchers worldwide are opting to develop new drug like molecules with comparatively lower market values.They start by first designing the analogues sharing structural and pharmacological similarities to the existing drugs. This method embark on scaffold structures of available drugs already approved by the clinical trials, but are left ineffective because of resistance developed by the pathogens. Conclusion: In this review we have stated some recent examples of anti-fungal and anti-bacterial (antimicrobial) drugs that were designed based on ABDD technique. Also we have tried to focus on the in silico tools and techniques that can contribute for the designing and computational screening of the analogues, so that these can be further taken for in vitro screening to validate their better biological activities against the pathogens with comparatively reduced rates of failure.

MICROBIOLOGICAL STUDIES OF APPALACHIAN PODSOL SOILS: II. SEASONAL CHANGES IN MICROBIAL ACTIVITY

1935 ◽  
Vol 13c (6) ◽  
pp. 358-366 ◽  
Author(s):  
P. H. H. Gray ◽  
H. J. Atkinson
Keyword(s):  
Carbon Dioxide ◽  
Microbial Activity ◽  
Biological Activities ◽  
Seasonal Fluctuations ◽  
Plate Method ◽  
Chemical Treatments ◽  
Cropping Season ◽  
Second Year ◽  
Micro Organisms ◽  
Different Levels

Seasonal fluctuations in numbers of micro-organisms in soil, estimated by the plate method for bacteria and actinomyces and by the evolution of carbon dioxide, have been studied with samples of cultivated podsol soils, drawn from experimental fields under various treatments at three farms in the Eastern Townships region of Quebec, at intervals of six weeks during the cropping season in two years. The nature of the fluctuations in numbers of micro-organisms was similar in the three soils, which were situated many miles apart. In 1931 numbers were lower in summer than in spring and autumn; in 1932 numbers fell towards the end of the season. The evolution of carbon dioxide fluctuated to a comparatively less extent than the bacterial numbers, but there was general agreement in the direction of the changes in the two years. Biological activities in any one soil were at significantly different levels in the two years. There was an agreement between numbers of micro-organisms and the amount of carbon dioxide, in that changes in both of these factors were in the same direction in the second year of sampling; there was also evidence of agreement between intra-annual changes in numbers and carbon dioxide, especially in the alkali-treated plots. Fluctuations in numbers and carbon dioxide in samples from plots in different parts of the same field or farm were in conformity, and were superimposed on the effects of chemical treatments that caused significant increases in microbial activity.

Chemistry and biology of Okinawan marine natural products

2009 ◽  
Vol 81 (6) ◽  
pp. 1009-1018 ◽  
Author(s):  
Jun'ichi Kobayashi
Keyword(s):  
Natural Products ◽  
Marine Natural Products ◽  
Shape Change ◽  
Biological Activities ◽  
Yeast Cells ◽  
Receptor Ligands ◽  
Hybrid Molecules ◽  
Adenosine Receptor Ligands ◽  
Micro Organisms ◽  
Cytotoxic Macrolide

Marine macro- and micro-organisms collected in Okinawa are good sources of compounds with intriguing structures and interesting biological activities. Synthetic hybrid molecules of caffeine and eudistomin D from tunicates Eudistoma sp. were found to show better potency as adenosine receptor ligands than caffeine, and one of them exhibits potent activity for adenosine receptors tested, especially for A3 subtype. Potent cytotoxic polyene macrolides from a tunicate Cystodytes sp. were found to be potent osteoclast inhibitors and to inhibit vacuolar type H+-ATPase (V-ATPase) of both mammalian and yeast cells. Amphidinolactones A and B are new macrolides from a dinoflagellate Amphidinium sp., and a potent cytotoxic macrolide from another strain was found to target actin cytoskeleton. Theonezolide A, a long-chain polyketide from a sponge Theonella sp., induces a drastic shape change in platelets by reorganization of microtubules. The stereochemistry of many chiral centers in theonezolide A was elucidated by spectral data and chemical means. Metachromins L-Q are new sesquiterpenoid quinones with an amino acid residue, while nakijiquinones E and F were the first dimeric sesquiterpenoid quinones possessing a 3-aminobenzoate moiety. Halichonadin E is the first hetero-dimeric sesquiterpenoid with eudesmane and aromadendrane skeletons linked through a urea fragment isolated from a sponge Halichondria sp. Pyrinadine A and nakinadine A are novel bis-pyridine alkaloids from sponges, while nagelamides are new bromopyrrole alkaloids from a sponge Agelas sp. Here, the structures and bioactivities of these interesting marine natural products will be described.

scholarly journals Sesquiterpenoids Specially Produced by Fungi: Structures, Biological Activities, Chemical and Biosynthesis (2015–2020)

2021 ◽  
Vol 7 (12) ◽  
pp. 1026
Author(s):  
Quan Dai ◽  
Fa-Lei Zhang ◽  
Tao Feng
Keyword(s):  
Natural Products ◽  
Biological Activities ◽  
Biologically Active ◽  
Structural Variations ◽  
Marine Habitat ◽  
Ecological Functions ◽  
Terrestrial Environment ◽  
Eukaryotic Microbes ◽  
Micro Organisms ◽  
Active Natural

Fungi are widely distributed in the terrestrial environment, freshwater, and marine habitat. Only approximately 100,000 of these have been classified although there are about 5.1 million characteristic fungi all over the world. These eukaryotic microbes produce specialized metabolites and participate in a variety of ecological functions, such as quorum detection, chemical defense, allelopathy, and maintenance of symbiosis. Fungi therefore remain an important resource for the screening and discovery of biologically active natural products. Sesquiterpenoids are arguably the richest natural products from plants and micro-organisms. The rearrangement of the 15 high-ductility carbons gave rise to a large number of different skeletons. At the same time, abundant structural variations lead to a diversification of biological activity. This review examines the isolation, structural determination, bioactivities, and synthesis of sesquiterpenoids that were specially produced by fungi over the past five years (2015‒2020).

scholarly journals Production of Silver Nanoparticles by Escherichia coli: Green Approach

2020 ◽  
Vol 11 (3) ◽  
pp. 4084-4088
Author(s):  
Sivanjale Ravindrakumar ◽  
June Yeoh Lee Xin ◽  
Hanan Rahman SK ◽  
Sabrina Harudsamy ◽  
Shamala Marimuthu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Biological Activities ◽  
Bacterial Biomass ◽  
Cytotoxicity Activity ◽  
Green Approach ◽  
Vis Spectroscopy ◽  
Cytotoxicity Activities ◽  
Micro Organisms ◽  
Physical And Chemical

Physical and chemical approaches to synthesize nanoparticles are not suitable for safer medical usage. Thus, green method could be a suitable approach to produce safe and non-toxic nanoparticles. In this study, silver nanoparticles were synthesized by Escherichia coli and its biological activities were determined. The produced bacterial biomass (supernatant) was mixed with silver nitrate to produce silver nanoparticles. Escherichia coli acting as reducing agents to produce nanoparticles. The colour changes from colourless to brown was observed to indicate the formation of silver nanoparticles. It was further reconfirmed using UV-Vis Spectroscopy, where the peak at 300 nm confirmed the formation of AgNPs. The antimicrobial and cytotoxicity activity of synthesized nanoparticles was tested. At 1 mg/ml concentration, the nanoparticles were effective against all the micro-organisms tested, Bacillus subtilis (12.7±2.5 mm) Staphylococcus aureus (13.7±2.3 mm), Pseudomonas aeruginosa (14.3±2.3 mm) and Aspergillus niger (12.7±2.1 mm). With decreasing concentration, the antimicrobial activity also decreased. Similar results were obtained when the nanoparticles were tested for cytotoxicity ability on HeLa cells. With increasing concentration, more of the tumor cells were inhibited. Based on the result obtained, it can be concluded that Escherichia coli can be used in the production of silver nanoparticles. It was found that synthesized nanoparticles possess effective antimicrobial and cytotoxicity activities. Thus, these properties could make them an advancing field in the medical world.

Review of the Radiation Damage Problem of Organic Specimens in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 476-477
Author(s):  
L. Reimer
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Irradiation Time ◽  
Dose Effect ◽  
Primary Process ◽  
Thin Specimen ◽  
Secondary Damage ◽  
Small Doses ◽  
Micro Organisms ◽  
Damage Processes

Most information about a specimen is obtained by elastic scattering of electrons, but one cannot avoid inelastic scattering and therefore radiation damage by ionisation as a primary process of damage. This damage is a dose effect, being proportional to the product of lectron current density j and the irradiation time t in Coul.cm−2 as long as there is a negligible heating of the specimen.Therefore one has to determine the dose needed to produce secondary damage processes, which can be measured quantitatively by a chemical or physical effect in the thin specimen. The survival of micro-organisms or the decrease of photoconductivity and cathodoluminescence are such effects needing very small doses (see table).

Functional amyloid: widespread in Nature, diverse in purpose

2014 ◽  
Vol 56 ◽  
pp. 207-219 ◽  
Author(s):  
Chi L.L. Pham ◽  
Ann H. Kwan ◽  
Margaret Sunde
Keyword(s):  
Spider Silk ◽  
Epigenetic Inheritance ◽  
Fibrillar Structure ◽  
Cytoplasmic Polyadenylation ◽  
Functional Amyloid ◽  
Interacting Protein ◽  
Diverse Range ◽  
Element Binding Protein ◽  
Functional Amyloids ◽  
Micro Organisms

Amyloids are insoluble fibrillar protein deposits with an underlying cross-β structure initially discovered in the context of human diseases. However, it is now clear that the same fibrillar structure is used by many organisms, from bacteria to humans, in order to achieve a diverse range of biological functions. These functions include structure and protection (e.g. curli and chorion proteins, and insect and spider silk proteins), aiding interface transitions and cell–cell recognition (e.g. chaplins, rodlins and hydrophobins), protein control and storage (e.g. Microcin E492, modulins and PMEL), and epigenetic inheritance and memory [e.g. Sup35, Ure2p, HET-s and CPEB (cytoplasmic polyadenylation element-binding protein)]. As more examples of functional amyloid come to light, the list of roles associated with functional amyloids has continued to expand. More recently, amyloids have also been implicated in signal transduction [e.g. RIP1/RIP3 (receptor-interacting protein)] and perhaps in host defence [e.g. aDrs (anionic dermaseptin) peptide]. The present chapter discusses in detail functional amyloids that are used in Nature by micro-organisms, non-mammalian animals and mammals, including the biological roles that they play, their molecular composition and how they assemble, as well as the coping strategies that organisms have evolved to avoid the potential toxicity of functional amyloid.

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