A natural association of a yeast with Aspergillus terreus and its impact on the host fungal biology

2021 ◽  
Author(s):  
Palak Arora ◽  
Amit Kumar ◽  
Ram A Vishwakarma ◽  
Syed Riyaz-Ul-Hassan
Keyword(s):  
Aspergillus Terreus ◽  
Direct Method ◽  
Stress Conditions ◽  
Yeast Cells ◽  
Symbiotic Association ◽  
Fungal Culture ◽  
Fungal Biology ◽  
Fungal Partner ◽  
Transmission Electron ◽  
Host Fungus

Abstract Several fungi have been shown to harbor microorganisms that regulate the key components of fungal metabolism. We explored the symbiotic association of an endophyte, Aspergillus terreus which led to the isolation of a yeast, Meyerozyma caribbica as its symbiont. An axenic fungal culture, free of the symbiont, was developed to study the effect of this association on the endophytic fungus. The symbiotic yeast partner was found to play an important role in the adaptation of A. terreus to thermal as well as osmotic stress. Under these stress conditions, the symbiont enhanced the production of lovastatin and the growth of the host fungus. The symbiotic yeast was found to induce the expression of the global regulator gene, the key genes involved in the lovastatin biosynthetic pathway as well as those involved in general growth and development, under stress conditions, in the fungal partner. Analysis by PCR and FISH microscopy indicated that the yeast may be present inside the hyphae of the fungus. However, a direct method like transmission electron microscopy may help to better understand the dynamics of this association including the distribution of the yeast cells in/on the fungal hyphae and spores.

Three-Dimensional Immunoelectron Microscopy of Yeast Cells by a New High-Resolution Replica Method

1985 ◽  
Vol 43 ◽  
pp. 562-563
Author(s):  
Hirano T. ◽  
M. Yamaguchi ◽  
M. Hayashi ◽  
Y. Sekiguchi ◽  
A. Tanaka
Keyword(s):  
High Resolution ◽  
Plasma Polymerization ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Replica Method ◽  
Yeast Cells ◽  
Dynamic Aspect ◽  
Replica Technique ◽  
Gaseous Hydrocarbon ◽  
Transmission Electron

A plasma polymerization film replica method is a new high resolution replica technique devised by Tanaka et al. in 1978. It has been developed for investigation of the three dimensional ultrastructure in biological or nonbiological specimens with the transmission electron microscope. This method is based on direct observation of the single-stage replica film, which was obtained by directly coating on the specimen surface. A plasma polymerization film was deposited by gaseous hydrocarbon monomer in a glow discharge.The present study further developed the freeze fracture method by means of a plasma polymerization film produces a three dimensional replica of chemically untreated cells and provides a clear evidence of fine structure of the yeast plasma membrane, especially the dynamic aspect of the structure of invagination (Figure 1).

scholarly journals Visualization of Chromatin in the Yeast Nucleus and Nucleolus Using Hyperosmotic Shock

2021 ◽  
Vol 22 (3) ◽  
pp. 1132
Author(s):  
Nicolas Thelen ◽  
Jean Defourny ◽  
Denis L. J. Lafontaine ◽  
Marc Thiry
Keyword(s):  
Osmotic Shock ◽  
Size Composition ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Cell Nuclei ◽  
Hyperosmotic Shock ◽  
Christmas Trees ◽  
Transmission Electron ◽  
Active Transcription ◽  
Decondensed Chromatin

Unlike in most eukaryotic cells, the genetic information of budding yeast in the exponential growth phase is only present in the form of decondensed chromatin, a configuration that does not allow its visualization in cell nuclei conventionally prepared for transmission electron microscopy. In this work, we studied the distribution of chromatin and its relationships to the nucleolus using different cytochemical and immunocytological approaches applied to yeast cells subjected to hyperosmotic shock. Our results show that osmotic shock induces the formation of heterochromatin patches in the nucleoplasm and intranucleolar regions of the yeast nucleus. In the nucleolus, we further revealed the presence of osmotic shock-resistant DNA in the fibrillar cords which, in places, take on a pinnate appearance reminiscent of ribosomal genes in active transcription as observed after molecular spreading (“Christmas trees”). We also identified chromatin-associated granules whose size, composition and behaviour after osmotic shock are reminiscent of that of mammalian perichromatin granules. Altogether, these data reveal that it is possible to visualize heterochromatin in yeast and suggest that the yeast nucleus displays a less-effective compartmentalized organization than that of mammals.

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

Effect of Gold Nanoparticles Size on Detection of Methylphosphonic Acid Hydrolysis Product of Nerve Agent

2021 ◽  
Vol 25 (7) ◽  
pp. 1-7
Author(s):  
Fellyzra Elvya Pojol ◽  
Buong Woei Chieng ◽  
Keat Khim Ong ◽  
Rashid Jahwarhar Izuan Abd ◽  
Mohd Junaedy Osman ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Inverse Method ◽  
Direct Method ◽  
Hydrolysis Product ◽  
Spherical Shape ◽  
Methylphosphonic Acid ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Citrate Reduction ◽  
Chloride Trihydrate

Citrate reduction of gold (III) chloride trihydrate (HAuCl4) is commonly used method to synthesise citrate-capped gold nanoparticles (cit-AuNPs). In this study, the sequence of reagents addition was modified (“inverse” method) to synthesise smaller size of cit-AuNPs than the standard Turkevich method (“direct” method). Ultraviolet-visible spectroscopy (UV-vis) and field emission transmission electron microscopy (FETEM) confirmed the formation of cit-AuNPs. The cit-AuNPs synthesized using “inverse” method are smaller in size (14.0 ± 3.03 nm) with uniform spherical shape compared to “direct” method (23.5 ± 7.52 nm). Smaller particles size of cit-AuNPs provide higher efficiency and sensitivity for detection of methylphosphonic acid (MPA) via colorimetric incorporated with image processing with a linear range from 2.5 to 12.5 mM and a low detection limit of 6.28 mM at shorter detection period (24 to 30 s).

scholarly journals Optimization of Innovative Three-Dimensionally-Structured Hybrid Vesicles to Improve the Cutaneous Delivery of Clotrimazole for the Treatment of Topical Candidiasis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 263 ◽  
Author(s):  
Maria Letizia Manca ◽  
Iris Usach ◽  
José Esteban Peris ◽  
Antonella Ibba ◽  
Germano Orrù ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Yeast Cells ◽  
Unilamellar Vesicles ◽  
Transmission Electron ◽  
Physico Chemical

New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (≤10%), which was replaced with a mixture of glycerol and ethanol (≈90%). A pre-formulation study was carried out to evaluate the effect of both the composition of the hydrating medium and the concentration of the phospholipid on the physico-chemical properties of hybrid vesicles. Four different three-dimensionally-structured hybrid vesicles were selected as ideal systems for the topical application of clotrimazole. An extensive physico-chemical characterization performed using transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), 31P-NMR, and small-angle X-ray scattering (SAXS) displayed the formation of small, multi-, and unilamellar vesicles very close to each other, and was capable of forming a three-dimensional network, which stabilized the dispersion. Additionally, the dilution of the dispersion with water reduced the interactions between vesicles, leading to the formation of single unilamellar vesicles. The evaluation of the in vitro percutaneous delivery of clotrimazole showed an improved drug deposition in the skin strata provided by the three-dimensionally-structured vesicles with respect to the commercial cream (Canesten®) used as a reference. Hybrid vesicles were highly biocompatible and showed a significant antifungal activity in vitro, greater than the commercial cream Canesten®. The antimycotic efficacy of formulations was confirmed by the reduced proliferation of the yeast cells at the site of infection in vivo. In light of these results, clotrimazole-loaded, three-dimensionally-structured hybrid vesicles appear to be one of the most innovative and promising formulations for the treatment of candidiasis infections.

SILVER NANOPARTICLE IMPREGNATED BIO-BASED ACTIVATED CARBON WITH ENHANCED ANTIMICROBIAL ACTIVITY

2013 ◽  
Vol 12 (04) ◽  
pp. 1350024 ◽  
Author(s):  
R. SELVAKUMAR ◽  
S. P. SURIYARAJ ◽  
V. JAYAVIGNESH ◽  
K. SWAMINATHAN
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Yeast Cells ◽  
X Ray Diffraction ◽  
Gram Positive ◽  
Biological Reduction ◽  
Gram Negative ◽  
Transmission Electron ◽  
Gram Negative Organisms ◽  
Average Size

The present study involves the production of silver nanoparticles using a novel yeast strain Saccharomyces cerevisiae BU-MBT CY-1 isolated from coconut cell sap. The biological reduction of silver nitrate by the isolate was deducted at various time intervals. The yeast cells after biological silver reduction were harvested and subjected to carbonization at 400°C for 1 h and its properties were analyzed using Fourier transform infra-red spectroscopy, X-ray diffraction, scanning electron microscope attached with energy dispersive spectroscopy and transmission electron microscopy. The average size of the silver nanoparticles present on the surface of the carbonized silver containing yeast cells (CSY) was 19 ± 9 nm. The carbonized control yeast cells (CCY) did not contain any particles on its surface. The carbonized silver nanoparticles containing yeast cells (CSY) were made into bioactive emulsion and tested for its efficacy against various pathogenic Gram positive and Gram negative bacteria. The antimicrobial activity studies indicated that CSY bioactive nanoemulsion was effective against Gram negative organisms than Gram positive organism.

scholarly journals Effect of symbiotic association of rhizobia and endomycorrhizae from Moroccan arid littoral dunes on Acacia cyanophylla tolerance to drought

2018 ◽  
Vol 2 (2) ◽  
pp. 39-45
Author(s):  
ABDELHAKIM HATIMI ◽  
SAIDIA TAHROUCH ◽  
BRAHIM BOUIZGARNE
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
High Efficiency ◽  
Stress Conditions ◽  
Symbiotic Association ◽  
Positive Effects ◽  
Acacia Cyanophylla ◽  
Growth And Nutrition ◽  
Bradyrhizobium Sp ◽  
Rhizobium Sp

Hatimi A, Tahrouch S, Bouizgarne B. 2018. Effect of symbiotic association of rhizobia and endomycorrhizae from Moroccan arid littoral dunes on Acacia cyanophylla tolerance to drought. Asian J For 2: 39-45. The research on behavior of A. cyanophylla Lindl plants associated with a symbiotic indigenous endomycorrhizal fungi M, and three rhizobia isolates: two low growing isolate R1 (Bradyrhizobium sp. RCM6), and R2 (Bradyrhizobium sp. RLC3) and a fast-growing isolates R3 (Rhizobium sp. S21), originated from coastal dunes of the Souss-Massa region in drought stress conditions, was investigated in greenhouse. Results have clearly shown that the growth and nutrition of seedlings of A. cyanophylla were drastically affected after two months in drought stress conditions. However, inoculation of the symbiotic microorganisms either alone (treatments M, RMC6, R2 or R3) or as inoculums consisting of combination of the rhizobia with the endomycorrhiza (treatments MR1, MR2 or MR3) resulted in enhanced tolerance of A. cyanophylla seedlings to drought stress. At 100% of field capacity (fc), all treatments showed a significant improvement of plant growth compared to non-inoculated plants in stress conditions. In addition, we have shown that Bradyrhizobium RCM6 (R1) holds a high efficiency to improve the growth and nutrition of the host plant. Indeed, higher number of nodules/plant and higher amount of total nitrogen were recorded in the seedlings inoculated with Bradyrhizobium sp. RCM6 in comparison with plants inoculated with the two other rhizobia Bradyrhizobium sp. RLC3 (R2) and Rhizobium sp. S21 (R3), and control plants. Dual inoculation with each of the three rhizobia and the endomycorrhizal complex (M) led to higher water content (W.C) and relative water content (RWC) and a significant increase in Phosphorus content of the aerial part. While positive effects were recorded for Phosphorus, no such effects were recorded for nitrogen. However, the overall results showed the importance of the use of microorganisms in the dune coastal environment particularly adequate tripartite association: rhizobia Endomycorrhizes-A. cyanophylla in enhancing tolerance to drought stress.

scholarly journals Understanding the Impact of Industrial Stress Conditions on Replicative Aging in Saccharomyces cerevisiae

2021 ◽  
Vol 2 ◽  
Author(s):  
Marco Eigenfeld ◽  
Roland Kerpes ◽  
Thomas Becker
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Real Time ◽  
High Throughput ◽  
Stress Conditions ◽  
Yeast Cells ◽  
Industrial Processes ◽  
Non Invasive ◽  
Age Related ◽  
Yeast Aging ◽  
The Impact

In yeast, aging is widely understood as the decline of physiological function and the decreasing ability to adapt to environmental changes. Saccharomyces cerevisiae has become an important model organism for the investigation of these processes. Yeast is used in industrial processes (beer and wine production), and several stress conditions can influence its intracellular aging processes. The aim of this review is to summarize the current knowledge on applied stress conditions, such as osmotic pressure, primary metabolites (e.g., ethanol), low pH, oxidative stress, heat on aging indicators, age-related physiological changes, and yeast longevity. There is clear evidence that yeast cells are exposed to many stressors influencing viability and vitality, leading to an age-related shift in age distribution. Currently, there is a lack of rapid, non-invasive methods allowing the investigation of aspects of yeast aging in real time on a single-cell basis using the high-throughput approach. Methods such as micromanipulation, centrifugal elutriator, or biotinylation do not provide real-time information on age distributions in industrial processes. In contrast, innovative approaches, such as non-invasive fluorescence coupled flow cytometry intended for high-throughput measurements, could be promising for determining the replicative age of yeast cells in fermentation and its impact on industrial stress conditions.

scholarly journals Optimization of ligninolytic enzymes production from Aspergillus terreus SG-777 by solid state fermentation

2016 ◽  
Vol 40 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Sahar Ghazi Imran
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Aspergillus Terreus ◽  
Production Condition ◽  
C:N Ratio ◽  
Ligninolytic Enzymes ◽  
Inoculum Size ◽  
Physical Parameters ◽  
Fungal Culture ◽  
Lignocellulosic Substrate

        The present study aimed at producing the ligninolytic enzymes extracts by growing single and co-cultures of an indigenous Aspergillus terreus SG-777 utilizing solid state fermentation (SSF) using lignocellulosic substrates. A further goal was to optimize the production condition of ligninolytic enzymes by selected fungal culture and lignocellulosic substrate. The production process was further improved by optimizing a number of physical parameters such as (substrate, incubation time, moisture level, inoculum size, pH, and temperature). By optimization of different parameters, the maximum specific activities of enzymes synthesized by Aspergillus terreus SG-777 were observed as 0.83 U/mg for manganese peroxidase (MnP), 18.03 U/mg for lignin peroxidase (LiP) and 0.91 U/mg for laccase,  when using the banana stalks as substrate after 8 days incubation at рH 5.5 and 35°C temperature with 1×105 spore/ml ml inoculum size, 1:5 w/v moisture content, 20:1 C:N ratio (glucose and ammonium tartarate as carbon and nitrogen supplements), 1ml of 1mM MnSO4 as mediator, and 1ml of 1mM MgSO4.7H2O2.

Effect of nanosecond and femtosecond pulse laser on the formation of WS2 nanostructures and field emission characteristics

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940014
Author(s):  
Pankaj Koinkar ◽  
Kohei Sasaki ◽  
Akihiro Furube ◽  
Kei-Ichiro Murai ◽  
Toshihiro Moriga ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Field Emission ◽  
Pulse Laser ◽  
Direct Method ◽  
Vital Role ◽  
Emission Characteristics ◽  
Liquid Environment ◽  
X Ray ◽  
Transmission Electron ◽  
Fs Laser

The pulse laser ablation is a simple and direct method used for the generation of nanostructures in liquid environment. In this paper, formation of tungsten sulfide [Formula: see text] nanostructures has been carried out using nanosecond (ns) and femtosecond (fs) laser ablation with ablation time 120 min. In addition, the field emission studies were performed of the prepared sample. The characterization techniques such as the transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-visible spectroscopy have been used to confirm the surface morphology as well as structural details. It is observed that the laser pulse regime plays a vital role on the size reduction of [Formula: see text] nanostructure. The X-ray spectra reveal the formation of [Formula: see text] nanoparticles for ns laser ablation, while [Formula: see text] nanosheets for fs laser ablation. The TEM images indicate that the transformation of [Formula: see text] microsheet into nanosheet of the size about 15–200 nm for the sample treated with ns laser and fs laser ablation. Also, the results clearly shows the improvement in the field emission characteristics for laser ablated [Formula: see text] nanosheets. The enhanced field emission characteristics is attributed to the formation and separation of few layer [Formula: see text] nanosheets. The [Formula: see text] nanostructures may have great potential for the applications in optoelectronic devices.

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