scholarly journals In vitro formation of Ca-oxalates and the mineral glushinskite by fungal interaction with carbonate substrates and seawater

2005 ◽  
Vol 2 (3) ◽  
pp. 277-293 ◽  
Author(s):  
K. Kolo ◽  
Ph. Claeys
Keyword(s):  
Raman Spectroscopy ◽  
Fungal Growth ◽  
Growth Media ◽  
Mineral Formation ◽  
Airborne Spores ◽  
Thin Sections ◽  
Metal Recycling ◽  
Textural Changes

Abstract. This study investigates the in vitro formation of Ca-oxalates and glushinskite through fungal interaction with carbonate substrates and seawater as a process of biologically induced metal recycling and neo-mineral formation. The study also emphasizes the role of the substrates as metal donors. In the first experiment, thin sections prepared from dolomitic rock samples of Terwagne Formation (Carboniferous, Viséan, northern France) served as substrates. The thin sections placed in Petri dishes were exposed to fungi grown from naturally existing airborne spores. In the second experiment, fungal growth and mineral formation was monitored using only standard seawater (SSW) as a substrate. Fungal growth media consisted of a high protein/carbohydrates and sugar diet with demineralized water for irrigation. Fungal growth process reached completion under uncontrolled laboratory conditions. The newly formed minerals and textural changes caused by fungal attack on the carbonate substrates were investigated using light and scanning electron microscopy (SEM-EDX), x-ray diffraction (XRD) and Raman spectroscopy. The fungal interaction and attack on the dolomitic and seawater substrates resulted in the formation of Ca-oxalates (weddellite CaC2O4·2(H2O), whewellite (CaC2O4·(H2O)) and glushinskite MgC2O4·2(H2O) associated with the destruction of the original hard substrates and their replacement by the new minerals. Both of Ca and Mg were mobilized from the experimental substrates by fungi. This metal mobilization involved a recycling of substrate metals into newly formed minerals. The biochemical and diagenetic results of the interaction strongly marked the attacked substrates with a biological fingerprint. Such fingerprints are biomarkers of primitive life. The formation of glushinskite is of specific importance that is related, besides its importance as a biomineral bearing a recycled Mg, to the possibility of its transformation through diagenetic pathway into an Mg carbonate. This work is the first report on the in vitro formation of the mineral glushinskite through fungal interaction with carbonate and seawater substrates. Besides recording the detailed Raman signature of various crystal habits of Mg- and Ca-oxalates, the Raman spectroscopy proved two new crystal habits for glushinskite. The results of this work document the role of microorganisms as metal recyclers in biomineralization, neo-mineral formation, sediment diagenesis, bioweathering and in the production of mineral and diagenetic biomarkers. They also reveal the capacity of living fungi to interact with liquid substrates and precipitate new minerals.

scholarly journals In vitro formation of Ca-oxalates and the mineral glushinskite by fungal interaction with carbonate substrates and seawater

2005 ◽  
Vol 2 (2) ◽  
pp. 451-497 ◽  
Author(s):  
K. Kolo ◽  
Ph. Claeys
Keyword(s):  
Sea Water ◽  
Fungal Growth ◽  
Growth Media ◽  
Mineral Formation ◽  
X Ray Diffraction ◽  
Airborne Spores ◽  
Thin Sections ◽  
Dolomitic Rock ◽  
Textural Changes

Abstract. This study investigates the in vitro formation of Ca-oxalates and glushinskite through fungal interaction with carbonate substrates and seawater. In the first experiment, thin-sections prepared from dolomitic rock samples of Terwagne Formation (Carboniferous, Viséan, northern France) served as substrates. The thin sections placed in Petri dishes were exposed to fungi grown from naturally existing airborne spores. In the second experiment, fungal growth and mineral formation was monitored using only standard seawater (SSW) as substrate. Fungal growth media consisted of a high protein/carbohydrates and sugar diet with demineralised water for irrigation. Fungal growth process reached completion under uncontrolled laboratory conditions. The fungal interaction and attack on the carbonate substrates resulted in the formation of Ca-oxalates (weddellite CaC2O4·2(H2O), whewellite (CaC2O4·(H2O)) and glushinskite MgC2O4·2(H2O) associated with the destruction of the original substrate and its replacement by the new minerals. The seawater substrate resulted also in the formation of glushinskite and Ca-oxalates. Both of Ca and Mg were mobilized from the experimental substrates by fungi. The newly formed minerals and textural changes caused by fungal attack on the carbonate substrate were investigated using light and scanning electron microscopy (SEM-EDX), x-ray diffraction (XRD) and Raman spectroscopy. The results document the role of microorganisms in biomineralization, neo-mineral formation and sediment diagenesis. They also reveal the capacity of living fungi to interact with liquid substrates and precipitate new minerals. This work is the first report on the in vitro formation of the mineral glushinskite through fungal-carbonate and sea water substrates interactions processes.

scholarly journals Synthetic Histidine-Rich Peptides Inhibit Candida Species and Other Fungi In Vitro: Role of Endocytosis and Treatment Implications

2006 ◽  
Vol 50 (8) ◽  
pp. 2797-2805 ◽  
Author(s):  
Jingsong Zhu ◽  
Paul W. Luther ◽  
Qixin Leng ◽  
A. James Mixson
Keyword(s):  
Nucleic Acid ◽  
Antifungal Activity ◽  
Antifungal Agents ◽  
Fungal Growth ◽  
Nucleic Acid Delivery ◽  
Histatin 5 ◽  
Ph Buffering ◽  
Endosomal Acidification

ABSTRACT A family of histidine-rich peptides, histatins, is secreted by the parotid gland in mammals and exhibits marked inhibitory activity against a number of Candida species. We were particularly interested in the mechanism by which histidine-rich peptides inhibit fungal growth, because our laboratory has synthesized a variety of such peptides for drug and nucleic acid delivery. In contrast to naturally occurring peptides that are linear, peptides made on synthesizers can be varied with respect to their degrees of branching. Using this technology, we explored whether histidine-lysine (HK) polymers of different complexities and degrees of branching affect the growth of several species of Candida. Polymers with higher degrees of branching were progressively more effective against Candida albicans, with the four-branched polymer, H2K4b, most effective. Furthermore, H2K4b accumulated efficiently in C. albicans, which may indicate its ability to transport other antifungal agents intracellularly. Although H2K4b had greater antifungal activity than histatin 5, their mechanisms were similar. Toxicity in C. albicans induced by histatin 5 or branched HK peptides was markedly reduced by 4,4′-diisothiocyanato-stilbene-2,2′-disulfonate, an inhibitor of anion channels. We also determined that bafilomycin A1, an inhibitor of endosomal acidification, significantly decreased the antifungal activity of H2K4b. This suggests that the pH-buffering and subsequent endosomal-disrupting properties of histidine-rich peptides have a role in their antifungal activity. Moreover, the ability of the histidine component of these peptides to disrupt endosomes, which allows their escape from the lysosomal pathway, may explain why these peptides are both effective antifungal agents and nucleic acid delivery carriers.

scholarly journals Effective medium for in vitro sprouting of the buds and multiplication of the plantlets, and identification of the fungal contaminant associated with the explants of Gnetum

2021 ◽  
Vol 16 (2) ◽  
pp. 001-013
Author(s):  
Abwe Mercy Ngone ◽  
Lawrence Monah Ndam ◽  
Rita Mungfu Njilar ◽  
Doungous Oumar ◽  
Thomas Eku Njock
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Fungal Growth ◽  
Growth Media ◽  
Fungal Contamination ◽  
Surface Sterilization ◽  
Pure Cultures ◽  
Nodal Cuttings ◽  
Baseline Information

Plant tissue culture requires the optimization of growth media. Gnetum, known locally in Cameroon as “Eru” is an indigenous gymnospermous vegetable with diverse medicinal, nutritional, cultural and socio-economic values. This resource is over-exploited and expected to neighboring countries, resulting to increased scarcity in the forest. Preliminary work on the in vitro culture of nodal cuttings was faced by the problem of fungal contamination. It was therefore necessary to isolate and identify the fungal contaminant, optimize the surface sterilization of field material and compose an appropriate medium for sprouting. Pure cultures of the fungus were obtained and grown on Potato Dextrose Agar (PDA) and Sabouraud Dextrose Agar (SDA). The identification was based on the appearance of the fungal growth on plates and also on the microscopic view. This was affected by the use of keys. Gnetum explants were disinfected with the various concentrations of disinfectants, preceded in some instances by pre-treatments, as well as incorporating fungicides in the culture medium. Two different culture media were employed: the Woody Plant Medium (WPM) and the Murashige and Skoog (MS) based establishment medium (Y-1). Gnetum was found to live in association with a complex of Microsporum species. The level of contamination of cultures was reduced from 100% to 40% when pre-treated before disinfection and even lower to 10% by incorporating fungicides in the medium. Sprouting was observed in WPM. This study provides baseline information on the in vitro propagation of Gnetum and thus opens up avenues for more research to be carried out in this field.

scholarly journals In Vitro Control of Phytophthora infestans and Alternaria solani Using Crude Extracts and Essential Oils from Selected Plants

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Lydia G. Mugao ◽  
Phyllis W. Muturi ◽  
Bernard M. Gichimu ◽  
Ezekiel K. Njoroge
Keyword(s):  
Essential Oils ◽  
Phytophthora Infestans ◽  
Radial Growth ◽  
Fungal Growth ◽  
Alternaria Solani ◽  
Growth Media ◽  
Distilled Water ◽  
Tomato Production ◽  
Crude Extracts

Tomato production is constrained by fungal diseases especially the early and late blight caused by Alternaria solani and Phytophthora infestans, respectively. Control of the two diseases is usually by use of synthetic fungicides which have a long residue effect and also contribute to environmental pollution. Innovative use of biocontrols may offer an eco-friendly and more sustainable solution. This study tested the in vitro efficacy of crude extracts and essential oils of ginger, garlic, tick berry, and Mexican marigold in inhibition of radial growth of A. solani and P. infestans. Extraction of the crude extracts was done using distilled water, ethanol, and methanol solvents, while essential oils were extracted using the dry steam distillation method. The extracts and essential oils were used to amend the growth media of the test pathogens before introducing the precultured pathogens. Sterile distilled water and synthetic fungicide, Ridomil Gold®, were used as positive and negative controls, respectively. Fungal growth inhibition was determined by measuring the radial growth of the test pathogens. Both the crude extracts and the essential oils portrayed some efficacy against the test pathogens. Garlic crude extracts were found to be the most effective, while ethanol was the most suitable extraction solvent. Essential oils were more effective in restricting the pathogen growth than crude extracts. Ginger and garlic oil was found to be as effective as the synthetic fungicide, and thus it was concluded that the two plants have strong antifungal properties with high potential of being utilized as biofungicides. However, effective utilization of these products in farmers’ fields may require industrial formulation to improve their efficiency.

Freeze-Fracture Observations of Hamster Sperm-Egg Fusion

1988 ◽  
Vol 46 ◽  
pp. 280-281
Author(s):  
Judy Clark ◽  
James K. Koehler
Keyword(s):  
In Vitro Fertilization ◽  
Freeze Fracture ◽  
Fusion Process ◽  
Thin Sections ◽  
Vitro Fertilization ◽  
Fertilization System ◽  
Sem Studies ◽  
Lipid Components

A number of TEM and SEM studies have made use of the hamster in vitro fertilization system to observe the process of sperm-egg fusion. We have extended these studies to include observations of freeze fracture replicas at the site of the sperm-egg interactions prior to, during and immediately following their fusion.Zona-free eggs were collected following superovulation of female hamsters according to the methods of Yanagimachi et al. Sperm were capacitated and prepared for incubation with eggs as in Clark et al. Eggs and sperm were co-incubated 5-15 minutes, washed and immediately fixed and prepared for freeze fracture replicas and thin sections as previously reported.In order to investigate the role of lipid components during the fusion process, some preparations were fixed in the presence of filipin, which binds to β-OH sterols in membranes and forms complexes that are visible in freeze fracture replicas. Thin sections were also prepared and viewed to help confirm and support observations of the replicas.

scholarly journals Chemical Composition and Antifungal Activity of Ocimum basilicum L. Essential Oil

2015 ◽  
Vol 3 (3) ◽  
pp. 374-379 ◽  
Author(s):  
Neveen Helmy Abou El-Soud ◽  
Mohamed Deabes ◽  
Lamia Abou El-Kassem ◽  
Mona Khalil
Keyword(s):  
Chemical Composition ◽  
Antifungal Activity ◽  
Essential Oil ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Fungal Growth ◽  
Ocimum Basilicum ◽  
Growth Media ◽  
Oil Concentration

BACKGROUND: The leaves of Ocimum basilicum L. (basil) are used in traditional cuisine as spices; its essential oil has found a wide application in perfumery, dental products as well as antifungal agents.AIM: To assess the chemical composition as well as the in vitro antifungal activity of O. basilicum L. essential oil against Aspergillus flavus fungal growth and aflatoxin B1 production.MATERIAL AND METHODS: The essential oil of O. basilicum was obtained by hydrodistillation and analysed using gas chromatography (GC) and GC coupled with mass spectrometry (GC/MS). The essential oil was tested for its effects on Aspergillus flavus (A. flavus) mycelial growth and aflatoxin B1 production in Yeast Extract Sucrose (YES) growth media. Aflatoxin B1 production was determined by high performance liquid chromatography (HPLC).RESULTS: Nineteen compounds, representing 96.7% of the total oil were identified. The main components were as follows: linalool (48.4%), 1,8-cineol (12.2%), eugenol (6.6%), methyl cinnamate (6.2%), α-cubebene (5.7%), caryophyllene (2.5%), β-ocimene (2.1%) and α-farnesene (2.0%).The tested oil showed significant antifungal activity that was dependent on the used oil concentration. The complete inhibition of A. flavus growth was observed at 1000 ppm oil concentration, while marked inhibition of aflatoxin B1 production was observed at all oil concentrations tested (500, 750 and 1000 ppm).CONCLUSION: These results confirm the antifungal activities of O. basilicum L. oil and its potential use to cure mycotic infections and act as pharmaceutical preservative against A. flavus growth and aflatoxin B1 production.

Abstract 450: Unveiling Human Cardiac Stem Cells Role in Myocardial Ischemia-reperfusion Injury

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Maria J Sebastião ◽  
Margarida Serra ◽  
Rute Pereira ◽  
Catarina Brito ◽  
Itziar Palacios ◽  
...  
Keyword(s):  
Stem Cells ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Maturation Stage ◽  
Growth Media ◽  
Cardiac Stem Cells ◽  
Myocardial Repair ◽  
Human Donor

After an Acute Myocardial Infarction (AMI), Ischemia-Reperfusion (I/R) injury is responsible for a critical decrease in the number of viable cardiomyocytes (hCMs). Human adult myocardium harbors a population of endogenous cardiac stem cells (hCSCs) that is activated upon I/R injury, contributing to myocardial repair through the establishment of an auto/paracrine molecular crosstalk between hCSCs and hCMs in stress. Our work aims at setting up the first in vitro human I/R injury model in order to decipher the role of hCSCs and correspondent cross talk between hCSCs and hCMs upon AMI using proteomic tools. Human CSCs, hCMs cultures and co-cultures were established using human donor derived CSCs (c-kit + , CD45 - ) and hCMs derived from human induced pluripotent stem cells at different maturation stages (hiPSC-CMs). Ischemia was mimicked by substituting growth media by Ischemia Mimetic Solution (including nutrient depletion, lactate accumulation, acidosis and hyperosmosis) and placing the cells at 0% O 2 for 5 hours. In the reperfusion step, cells were placed back in their physiological culture conditions (3% O 2 ). The effect of I/R injury on growth factor secretion, cells’ viability, as well as on hCSC proliferation was accessed in both mono- and co-culture systems. In addition, hCSCs total proteome analysis was performed at different timepoints (before injury, after ischemia and after 1h and 16h of reoxygenation) by LC-MS. Important features of I/R injury were successfully captured in our model, namely hCSC proliferation activation upon insult, the increase in HGF secretion during the first hour after reoxygenation, and the protective role of hCSCs on hiPSC-CMs. The maturation stage of hiPSC-CM showed to be of high relevance in the response to injury. More than 2000 proteins were identified in hCSCs per experimental time point; proteins associated with mitochondrial dysfunction and oxidative stress response were identified in hCSCs exposed to injury. This system will allow further understanding on the molecular landscape of the myocardium during AMI, namely regarding hCSC regenerative response and hCM survival. The knowledge gained in this work will potentiate the development of novel therapies for myocardium regeneration.

Fungal Growth inside Saline-Filled Implants and the Role of Injection Ports in Fungal Translocation: In Vitro Study

2004 ◽  
pp. 1170-1178 ◽  
Author(s):  
Aydin Saray ◽  
Dilek Kilic ◽  
Sedat Kaygusuz ◽  
Hakan Boyunaga ◽  
??zlem ??zl??k
Keyword(s):  
Fungal Growth ◽  
In Vitro Study ◽  
Vitro Study

scholarly journals Pericyte-Like Cells Undergo Transcriptional Reprogramming and Distinct Functional Adaptations in Acute Lung Injury

2019 ◽  
Author(s):  
CF Hung ◽  
S Holton ◽  
YH Chow ◽  
WC Liles ◽  
SA Gharib ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Fas Ligand ◽  
Functional Enrichment ◽  
Growth Media ◽  
Transcriptional Responses ◽  
Functional Changes

AbstractBackgroundWe previously reported on the role of pericyte-like cells as functional sentinel immune cells in lung injury. However, much about the biological role of pericytes in lung injury remains unknown. Lung pericyte-like cells are well-positioned to sense disruption to the epithelial barrier and coordinate local inflammatory responses due to their anatomic niche within the alveoli. In this report, we characterized transcriptional responses and functional changes in pericyte-like cells following activation by alveolar components from injured and uninjured lungs in a mouse model of acute lung injury (ALI).MethodsWe purified pericyte-like cells from lung digests using PDGFRβ as a selection marker and expanded them in culture as previously described (1). We induced sterile acute lung injury in mice with recombinant human Fas ligand (rhFasL) instillation followed by mechanical ventilation (1). We then collected bronchoalveolar lavage fluid (BALF) from injured and uninjured mice. Purified pericyte-like cells in culture were exposed to growth media only (control), BALF from uninjured mice, and BALF from injured mice for 6 and 24 h. RNA collected from these treatment conditions were processed for RNAseq. Targets of interest identified by pathway analysis were validated using in vitro and in vivo assays.ResultsWe observed robust global transcriptional changes in pericyte-like cells following treatment with uninjured and injured BALF at 6 h, but this response persisted for 24 h only after exposure to injured BALF. Functional enrichment analysis of pericytes treated with injured BALF revealed activation of immuno-inflammatory, cell migration and angiogenesis-related pathways, whereas processes associated with tissue development and remodeling were down-regulated. We validated select targets in the inflammatory, angiogenesis-related, and cell migratory pathways using functional biological assays in vitro and in vivo.ConclusionLung pericyte-like cells are highly responsive to alveolar compartment content from both uninjured and injured lungs, but injured BALF elicits a more sustained response. The inflammatory, angiogenic, and migratory changes exhibited by activated pericyte-like cells underscore the phenotypic plasticity of these specialized stromal cells in the setting of acute lung injury.

scholarly journals Influence of H2O2-Induced Oxidative Stress on In Vitro Growth and Moniliformin and Fumonisins Accumulation by Fusarium proliferatum and Fusarium subglutinans

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 653
Author(s):  
Davide Ferrigo ◽  
Valentina Scarpino ◽  
Francesca Vanara ◽  
Roberto Causin ◽  
Alessandro Raiola ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Fungal Growth ◽  
Fungal Species ◽  
Fusarium Proliferatum ◽  
Fusarium Subglutinans ◽  
H2o2 Treatment ◽  
Mycotoxin Production ◽  
The Stability

Fusarium proliferatum and Fusarium subglutinans are common pathogens of maize which are known to produce mycotoxins, including moniliformin (MON) and fumonisins (FBs). Fungal secondary metabolism and response to oxidative stress are interlaced, where hydrogen peroxide (H2O2) plays a pivotal role in the modulation of mycotoxin production. The objective of this study is to examine the effect of H2O2-induced oxidative stress on fungal growth, as well as MON and FBs production, in different isolates of these fungi. When these isolates were cultured in the presence of 1, 2, 5, and 10 mM H2O2, the fungal biomass of F. subglutinans isolates showed a strong sensitivity to increasing oxidative conditions (27–58% reduction), whereas F. proliferatum isolates were not affected or even slightly improved (45% increase). H2O2 treatment at the lower concentration of 1 mM caused an almost total disappearance of MON and a strong reduction of FBs content in the two fungal species and isolates tested. The catalase activity, surveyed due to its crucial role as an H2O2 scavenger, showed no significant changes at 1 mM H2O2 treatment, thus indicating a lack of correlation with MON and FB changes. H2O2 treatment was also able to reduce MON and FB content in certified maize material, and the same behavior was observed in the presence and absence of these fungi, highlighting a direct effect of H2O2 on the stability of these mycotoxins. Taken together, these data provide insights into the role of H2O2 which, when increased under stress conditions, could affect the vegetative response and mycotoxin production (and degradation) of these fungi.

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