scholarly journals Optimization of the Nutrient Medium for Flammulina velutipes Submerged Biomass Production and Micromorphology of Its Mycelium

Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 180
Author(s):  
Larissa Krasnopolskaya ◽  
Maria Shuktueva ◽  
Aleksandr Golyshkin ◽  
Nailya Almyasheva ◽  
Maria Yarina

Based on the assessment of the trophic needs of basidiomycete Flammulina velutipes and the optimization of the composition of the nutrient medium using design of experimental approach, the yield of the submerged biomass of the fungus was increased to 41 g/L, the duration of the cultivation process was reduced to 5 days. For this purpose, the 24 full factorial design, the Box–Wilson steep ascent method and the construction of the response surface were used. Using the method of scanning electron microscopy, it was shown that the studied F. velutipes strain grew in the form of small spherical pellets with a diameter of 1–2 mm on an optimized medium. The surface of the pellets was loose; the inner part was filled with hyphae tightly adjacent to each other. The center of the pellets had no cavity. F. velutipes pellets were formed by septate hyphae with clamp connections. The micromorphological characteristics of the submerged F. velutipes mycelium ensured a high diffusion of nutrients and oxygen into the pellets and their maximum filling of the volume of the culture medium.

Author(s):  
E.C. Chew ◽  
D.J. Riches ◽  
P.P.L. Tam ◽  
G.S.W. Tsao ◽  
T.K. Lam ◽  
...  

The use of microwave irradiation for fixation of human and animal tissue has been proven satisfactory at light microscopic and electron microscopic levels. The present communication reports the study of the same method of fixation of cell cultures for scanning electron microscopy.Trophoblasts were isolated from the placentae of mouse conceptuses at 10.5 days of gestation. The placenta was dissected out from the decidua and placed in Ca and Mg-free PBS, minced and then forced through a gauge-21 syringe needle. The tissue fragments were digested with 0.25% trypsin in Ca and Mg-free PBS for 20 - 30 minutes at 4°C. The digested tissue was then washed with complete PB1 medium. A single-cell suspension was obtained by spinning down the larger fragments by centrifugation. A known volume of the single-cell suspension was added to the culture medium (DCMEM and 20% FCS). The culture medium was changed after 24 hours to remove any unattached cells.


2009 ◽  
Vol 71-73 ◽  
pp. 381-384
Author(s):  
Tuomas van der Meer ◽  
Jussi Liipo ◽  
Jaakko Leppinen

The effect of different microbial consortia on the leaching of chalcopyrite was studied at different temperatures and solution compositions with Boliden’s Aitik ore in column reactors simulating heap bioleaching. The columns were equipped with sampling chambers and chalcopyrite mineral electrodes in order to investigate the passivation of chalcopyrite. The sampling chambers were filled with agglomerated ore and pieces of chalcopyrite-rich ore. In addition to chemical analysis of the leaching solution and solids the progress of leaching of chalcopyrite was studied by continuous potential measurements with chalcopyrite electrodes. The occurrence and composition of potentially passivating layers on the surfaces of the electrodes and the samples taken from sample chambers were examined by optical and scanning electron microscopy.


2005 ◽  
Vol 901 ◽  
Author(s):  
Timothy Gutu ◽  
Jun Jiao ◽  
Clayton Jeffryes ◽  
Tian Qin ◽  
Chih-hung Chang ◽  
...  

AbstractThe fabrication of Si-Ge oxide composites in a two-stage photobioreactor cultivation process was systematically optimized by increasing the amount of germanium assimilated into the diatom cells. In this optimization process of the synthesis of Si-Ge oxides that maintain the original morphology of the diatoms, high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) both equipped with an energy dispersive X-ray spectrometer were extensively used to characterize the evaluation of the chemical composition and structural properties of the processed diatoms.


2010 ◽  
Vol 76 (21) ◽  
pp. 7292-7298 ◽  
Author(s):  
Allison M. Horst ◽  
Andrea C. Neal ◽  
Randall E. Mielke ◽  
Patrick R. Sislian ◽  
Won Hyuk Suh ◽  
...  

ABSTRACT Engineered nanoparticles are increasingly incorporated into consumer products and are emerging as potential environmental contaminants. Upon environmental release, nanoparticles could inhibit bacterial processes, as evidenced by laboratory studies. Less is known regarding bacterial alteration of nanoparticles, including whether bacteria affect physical agglomeration states controlling nanoparticle settling and bioavailability. Here, the effects of an environmental strain of Pseudomonas aeruginosa on TiO2 nanoparticle agglomerates formed in aqueous media are described. Environmental scanning electron microscopy and cryogenic scanning electron microscopy visually demonstrated bacterial dispersion of large agglomerates formed in cell culture medium and in marsh water. For experiments in cell culture medium, quantitative image analysis verified that the degrees of conversion of large agglomerates into small nanoparticle-cell combinations were similar for 12-h-growth and short-term cell contact experiments. Dispersion in cell growth medium was further characterized by size fractionation: for agglomerated TiO2 suspensions in the absence of cells, 81% by mass was retained on a 5-μm-pore-size filter, compared to only 24% retained for biotic treatments. Filtrate cell and agglomerate sizes were characterized by dynamic light scattering, revealing that the average bacterial cell size increased from 1.4 μm to 1.9 μm because of nano-TiO2 biosorption. High-magnification scanning electron micrographs showed that P. aeruginosa dispersed TiO2 agglomerates by preferential biosorption of nanoparticles onto cell surfaces. These results suggest a novel role for bacteria in the environmental transport of engineered nanoparticles, i.e., growth-independent, bacterially mediated size and mass alterations of TiO2 nanoparticle agglomerates.


2021 ◽  
Vol 29 (6) ◽  
pp. 38-41
Author(s):  
Sandy M.S. McLachlan ◽  
Elaine C. Humphrey

Abstract:We describe an experimental approach for achieving an optimal black background for scanning electron photomicrographs of small samples with elaborate and intricate structures. Specimens of the highly ornate, 66-million-year-old chorate dinoflagellate cyst species Cannosphaeropsis franciscana were selected as the subject of this study. Photomicrographs collected following standard aluminum stub surface placement were compared to those taken of specimens mounted using a novel pin-and-pedestal method. This simplistic mounting technique minimizes the need for post-production image editing and extraneous background removal.


Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).


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