Taxonomic and ecological characterization of two Ulnaria species (Bacillariophyta) from streams in Cyprus

Phytotaxa ◽  
2018 ◽  
Vol 346 (1) ◽  
pp. 78 ◽  
Author(s):  
MARCO CANTONATI ◽  
HORST LANGE-BERTALOT ◽  
MARTYN G. KELLY ◽  
NICOLA ANGELI
Keyword(s):  
Central Area ◽  
New Combination ◽  
Subtropical Climate ◽  
Diatom Assemblages ◽  
Important Species ◽  
Ecological Preferences ◽  
Low Concentrations ◽  
Literature Searches ◽  
Conductivity Range

During a study of the diatoms of streams in Cyprus, two Ulnaria species were difficult to identify using current taxonomic concepts, which created difficulties when trying to understand their ecological preferences. As a result, both taxa were investigated in detail using light (LM) and scanning electron (SEM) microscopy. Literature searches showed that one of these corresponds to Synedra Monodi Guermeur, a “forgotten” species often misidentified as Fragilaria biceps. This species was shown to belong to the genus Ulnaria, and a new combination is provided together with LM and SEM illustrations and an expanded description. U. monodii appears to be widely distributed and was sometimes abundant. It is an important species in diatom assemblages in streams with relatively warm waters (Mediterranean or tropical / subtropical climate). The second species, one of several forms to which the name Ulnaria acus has often been inappropriately applied, is described as a species new to science (Ulnaria acuscypriacus sp. nov.). The new species differs from all similar taxa by a combination of characters including width, outline, central area shape, and the possession of biseriate areolae. A comprehensive environmental dataset allowed the ecological preferences of Ulnaria monodii comb. nov. to be established. This species was generally associated with low concentrations of total nitrogen and total phosphorus, corresponding to slightly nutrient enriched situations. By contrast, the low number of occurrences of U. acuscypriacus sp. nov. did not allow us to identify clear nutrient preferences. U. acuscypriacus sp. nov. was observed across a large conductivity range, suggesting that it may be more tolerant of brackish conditions than Ulnaria monodii comb. nov.

New and interesting aerial diatom assemblages from southwestern Iceland

Phytotaxa ◽  
2020 ◽  
Vol 428 (3) ◽  
pp. 173-208
Author(s):  
PAULA C. FUREY ◽  
KALINA M. MANOYLOV ◽  
REX L. LOWE
Keyword(s):  
Volcanic Rock ◽  
Central Area ◽  
Diatom Assemblages ◽  
Rock Outcrops ◽  
Diatom Flora ◽  
Abundance Estimates ◽  
Northern Regions ◽  
Algal Assemblages ◽  
Limited Moisture

Examination of algal assemblages from aerial environments around the globe, especially those from pseudoaerial habitats found on moistened rocks underneath waterfalls or around springs and seeps, reveals the presence of unique diatom floras. Yet, diatom assemblages from northern regions like Iceland remain understudied, especially those from the volcanic rock outcrops and boulders that create euaerial habitats where biota receive moisture from the atmosphere or the rock itself. During the summers of 2013 and 2015, we examined the biodiversity of mostly euaerial, but also pseudoaerial, diatom assemblages collected from volcanic rock outcrops or large boulders on the landscape from southwestern Iceland. We used light and scanning electron microscopy to document the biodiversity of common, smaller, new, or interesting specimens, such as Humidophila and Eunotia. We describe one new Humidophila species, H. eldfjallii sp. nov., with triundulate valve margins and include information on another unidentified taxon, Humidophila sp. 1, naviculoid in shape with tapering to rounded ends, continuous striae through the length of the valve, and a circular central area. We formally transfer Diadesmis contenta var. biceps to Humidophila biceps. To correct the nomenclature, we recognized Humidophila parallela at the species level. Relative abundance estimates of diatom populations provided further characterization of the assemblages on these habitats. Humidophila taxa, especially H. gallica dominated the diverse diatom flora. We discuss adaptations for survival with access to mostly atmospheric water. The diatom flora described here adds to the flora for this region, highlights the diversity of diatom assemblages that can inhabit euaerial environments, and provides evidence of adaptive success of diatoms in extreme habitats with limited moisture and nutrients.

scholarly journals New Trimethoprim-Like Molecules: Bacteriological Evaluation and Insights into Their Action

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 709
Author(s):  
Marta Jorba ◽  
Marina Pedrola ◽  
Ouldouz Ghashghaei ◽  
Rocío Herráez ◽  
Lluis Campos-Vicens ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Detailed Characterization ◽  
Low Concentrations ◽  
Pump Activity ◽  
Bacteriological Evaluation ◽  
Kinetics Of

This work reports a detailed characterization of the antimicrobial profile of two trimethoprim-like molecules (compounds 1a and 1b) identified in previous studies. Both molecules displayed remarkable antimicrobial activity, particularly when combined with sulfamethoxazole. In disk diffusion assays on Petri dishes, compounds 1a and 1b showed synergistic effects with colistin. Specifically, in combinations with low concentrations of colistin, very large increases in the activities of compounds 1a and 1b were determined, as demonstrated by alterations in the kinetics of bacterial growth despite only slight changes in the fractional inhibitory concentration index. The effect of colistin may be to increase the rate of antibiotic entry while reducing efflux pump activity. Compounds 1a and 1b were susceptible to extrusion by efflux pumps, whereas the inhibitor phenylalanine arginyl β-naphthylamide (PAβN) exerted effects similar to those of colistin. The interactions between the target enzyme (dihydrofolate reductase), the coenzyme nicotinamide adenine dinucleotide phosphate (NADPH), and the studied molecules were explored using enzymology tools and computational chemistry. A model based on docking results is reported.

scholarly journals Plasma proteomics of green turtles (Chelonia mydas) reveals pathway shifts and potential biomarker candidates associated with health and disease

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
David P Marancik ◽  
Justin R Perrault ◽  
Lisa M Komoroske ◽  
Jamie A Stoll ◽  
Kristina N Kelley ◽  
...  
Keyword(s):  
Chelonia Mydas ◽  
Sea Turtle ◽  
Protein Abundance ◽  
Plasma Samples ◽  
Important Species ◽  
Green Turtles ◽  
Rehabilitation Programs ◽  
Potential Biomarker ◽  
Health And Disease

Abstract Evaluating sea turtle health can be challenging due to an incomplete understanding of pathophysiologic responses in these species. Proteome characterization of clinical plasma samples can provide insights into disease progression and prospective biomarker targets. A TMT-10-plex-LC–MS/MS platform was used to characterize the plasma proteome of five, juvenile, green turtles (Chelonia mydas) and compare qualitative and quantitative protein changes during moribund and recovered states. The 10 plasma samples yielded a total of 670 unique proteins. Using ≥1.2-fold change in protein abundance as a benchmark for physiologic upregulation or downregulation, 233 (34.8%) were differentially regulated in at least one turtle between moribund and recovered states. Forty-six proteins (6.9%) were differentially regulated in all five turtles with two proteins (0.3%) demonstrating a statistically significant change. A principle component analysis showed protein abundance loosely clustered between moribund samples or recovered samples and for turtles that presented with trauma (n = 3) or as intestinal floaters (n = 2). Gene Ontology terms demonstrated that moribund samples were represented by a higher number of proteins associated with blood coagulation, adaptive immune responses and acute phase response, while recovered turtle samples included a relatively higher number of proteins associated with metabolic processes and response to nutrients. Abundance levels of 48 proteins (7.2%) in moribund samples significantly correlated with total protein, albumin and/or globulin levels quantified by biochemical analysis. Differentially regulated proteins identified with immunologic and physiologic functions are discussed for their possible role in the green turtle pathophysiologic response and for their potential use as diagnostic biomarkers. These findings enhance our ability to interpret sea turtle health and further progress conservation, research and rehabilitation programs for these ecologically important species.

scholarly journals Characterization of adenosine deaminase (ADA) in Hemolymph of Biomphalaria glabrata

2005 ◽  
Vol 65 (2) ◽  
pp. 371-376 ◽  
Author(s):  
M. R. Vale ◽  
R. V. Pereira ◽  
S. M. Almeida ◽  
Y. M. Almeida ◽  
S. F. L. C. Nunes
Keyword(s):  
Adenosine Deaminase ◽  
Incubation Temperature ◽  
Small Variation ◽  
Healthy Human ◽  
Ph Variation ◽  
Cellular Events ◽  
Low Concentrations ◽  
Key Enzyme ◽  
Assay Conditions

Adenosine is an important signaling molecule for many cellular events. Adenosine deaminase (ADA) is a key enzyme for the control of extra- and intra-cellular levels of adenosine. Activity of ADA was detected in hemolymph of B. glabrata and its optimum assay conditions were determined experimentally. The pH variation from 6.2 to 7.8 caused no significant change in ADA activity. Using adenosine as a substrate, the apparent Km at pH 6.8 was 734 µmols.L-1. Highest activity was found at 37ºC. Standard assay conditions were established as being 15 minutes of incubation time, 0.4 µL of pure hemolymph per assay, pH 6.8, and 37ºC. This enzyme showed activities of 834 ± 67 µmol.min-1.L-1 (25ºC) and 2029 ± 74 µmol.min-1.L-1 (37ºC), exceeding those in healthy human serum by 40 and 100 times, respectively. Higher incubation temperature caused a decrease in activity of 20% at 43ºC or 70% at 50ºC for 15 minutes. The ADA lost from 26 to 78% of its activity when hemolymph was pre-incubated at 50ºC for 2 or 15 minutes, respectively. Since the ADA from hemolymph presented high levels, it can be concluded that in healthy and fed animals, adenosine is maintained at low concentrations. In addition, the small variation in activity over the 6.2 to 7.8 range of pH suggests that adenosine is maintained at low levels in hemolymph even under adverse conditions, in which the pH is altered.

scholarly journals An Overview of Metabolic Activity, Beneficial and Pathogenic Aspects of Burkholderia Spp

Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 321
Author(s):  
Hazem S. Elshafie ◽  
Ippolito Camele
Keyword(s):  
Secondary Metabolites ◽  
Plant Growth ◽  
Biochemical Characterization ◽  
Bacterial Species ◽  
Promoting Effect ◽  
Important Species ◽  
Beneficial Effects ◽  
Plant Growth Promoting ◽  
Rhizosphere Competence

Burkholderia is an important bacterial species which has different beneficial effects, such as promoting the plant growth, including rhizosphere competence for the secretion of allelochemicals, production of antibiotics, and siderophores. In addition, most of Burkholderia species have demonstrated promising biocontrol action against different phytopathogens for diverse crops. In particular, Burkholderia demonstrates significant biotechnological potential as a source of novel antibiotics and bioactive secondary metabolites. The current review is concerned with Burkholderia spp. covering the following aspects: discovering, classification, distribution, plant growth promoting effect, and antimicrobial activity of different species of Burkholderia, shedding light on the most important secondary metabolites, their pathogenic effects, and biochemical characterization of some important species of Burkholderia, such as B. cepacia, B. andropogonis, B. plantarii, B. rhizoxinica, B. glumae, B. caryophylli and B. gladioli.

LOCALIZATION AND CHARACTERIZATION OF CHOLINESTERASE IN SUBCELLULAR FRACTIONS OF RAT BRAIN AND BEEF PITUITARY

1961 ◽  
Vol 39 (9) ◽  
pp. 1335-1345 ◽  
Author(s):  
Surendra S. Parmar ◽  
Morley C. Sutter ◽  
Mark Nickerson
Keyword(s):  
Rat Brain ◽  
Cholinesterase Activity ◽  
Succinic Dehydrogenase ◽  
Anterior Lobe ◽  
Subcellular Fractions ◽  
Posterior Pituitary ◽  
Low Concentrations ◽  
Pituitary Glands ◽  
Hydrolysis Of

Fresh rat brains and fresh anterior and posterior pituitary glands of beef were separated by differential centrifugation into subcellular fractions, characterized on the basis of sedimentation and succinic dehydrogenase activity. Cholinesterase activity was measured by both manometric and colorimetric methods, the results of which were comparable. Cholinesterase activity of rat brain was found mainly in the microsome and supernatant fractions. It was quite uniformly distributed in all subcellular fractions of both anterior and posterior pituitary. Comparisons of the relative rates of hydrolysis of acetylthiocholine and butyrylthiocholine, and of inhibition by eserine, indicated that brain contains a much higher percentage of acetylcholinesterase than do both lobes of the pituitary, which contain relatively low concentrations of the specific enzyme. Total cholinesterase activity and its sensitivity to inhibition by eserine in the posterior pituitary were found to be midway between those of the anterior lobe and of the brain, from which the posterior pituitary was derived during embryological development.

scholarly journals Silver Nanoparticles: An Instantaneous Solution for Anticancer Activity against Human Liver (HepG2) and Breast (MCF-7) Cancer Cells

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 148
Author(s):  
Abdulaziz A. Al-Khedhairy ◽  
Rizwan Wahab
Keyword(s):  
Silver Nanoparticles ◽  
Cancer Cells ◽  
Human Liver ◽  
Quantitative Polymerase Chain Reaction ◽  
Cell Types ◽  
Whole Body ◽  
Low Concentrations ◽  
Excellent Control ◽  
Mcf 7

Cancer is a cataclysmic disease that affects not only the target organ, but also the whole body. Metal-based nanoparticles (NPs) have recently emerged as a better option for the treatment of this deadly disease. Accordingly, the present work describes a means to control the growth of cancer cells by using colloidal silver nanoparticles (AgNPs) processed via homemade solutions and the characterization of these materials. The AgNPs may become an instantaneous solution for the treatment of these deadly diseases and to minimize or remove these problems. The AgNPs exhibit excellent control of the growth rate of human liver (HepG2) and breast (MCF-7) cancer cells, even at a very low concentrations. The cytotoxic effects of AgNPs on HepG2 and MCF-7 cancer cells were dose dependent (2–200 μg/mL), as evaluated using MTT and NRU assays. The production of reactive oxygen species (ROS) was increased by 136% and 142% in HepG2 and MCF-7 cells treated with AgNPs, respectively. The quantitative polymerase chain reaction (qPCR) data for both cell types (HepG2 and MCF-7) after exposure to AgNPs showed up- and downregulation of the expression of apoptotic (p53, Bax, caspase-3) and anti-apoptotic (BCl2) genes; moreover, their roles were described. This work shows that NPs were successfully prepared and controlled the growth of both types of cancer cells.

scholarly journals Synthesis and characterization of silver nanoparticle-decorated cobalt nanocomposites (Co@AgNPs) and their density-dependent antibacterial activity

2019 ◽  
Vol 6 (5) ◽  
pp. 182135 ◽  
Author(s):  
Zakia Kanwal ◽  
Muhammad Akram Raza ◽  
Saira Riaz ◽  
Saher Manzoor ◽  
Asima Tayyeb ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Cobalt Acetate ◽  
X Ray Diffraction ◽  
Characteristic Analysis ◽  
Density Dependent ◽  
Antibacterial Performance ◽  
Magnetic Cores ◽  
Low Concentrations

Magnetic cores loaded with metallic nanoparticles can be promising nano-carriers for successful drug delivery at infectious sites. We report fabrication, characteristic analysis and in vitro antibacterial performance of nanocomposites comprising cobalt cores (Co-cores) functionalized with a varied concentration of silver nanoparticles (AgNPs). A two-step polyol process synchronized with the transmetalation reduction method was used. Co-cores were synthesized with cobalt acetate, and decoration of AgNPs was carried out with silver acetate. The density of AgNPs was varied by changing the amount of silver content as 0.01, 0.1 and 0.2 g in the synthesis solution. Both AgNPs and Co-cores were spherical having a size range of 30–80 nm and 200 nm to more than 1 µm, respectively, as determined by scanning electron microscopy. The metallic nature and face-centred cubic crystalline phase of prepared nanocomposites were confirmed by X-ray diffraction. Biocompatibility analysis confirmed high cell viability of MCF7 at low concentrations of tested particles. The antibacterial performance of nanocomposites (Co@AgNPs) against Escherichia coli and Bacillus subtilis was found to be AgNPs density-dependent, and nanocomposites with the highest AgNPs density exhibited the maximum bactericidal efficacy. We therefore propose that Co@AgNPs as effective drug containers for various biomedical applications.

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