scholarly journals Tenebrio molitor and its gut bacteria growth in polystyrene (PS) presence as the sole source carbon

2020 ◽  
Vol 25 (1) ◽  
pp. 37-53
Author(s):  
Paula M Peña-Pascagaza ◽  
Nathalia A López-Ramírez ◽  
Miguel A Ballen-Segura
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Source ◽  
Digestive Tract ◽  
Tenebrio Molitor ◽  
Sole Source ◽  
Biodegradable Material ◽  
Bacteria Growth ◽  
Natural Microbiota ◽  
Scanning Electron

Although polystyrene (PS) is considered a non-biodegradable material, recent work has shown the degradation capacity of this material by microorganisms, especially those that are part of the natural microbiota of the digestive tract of some invertebrates. The present work sought to evaluate the growth of the larva of the mealworm (Tenebrio molitor) and its bacteria, using PS as the sole source of carbon. In this way it was possible to demonstrate the consumption of PS plates by the larva, found in holes and tunnels in the material, however, nutritionally it is not enough for the larva to gain biomass, notably reducing its size and time survival. Similarly, bacteria isolated from the digestive tract of T. molitor presented the ability to generate biofilms o n PS s heets, g enerating c hanges ( cracks, holes, etc.) in them, which were observed under scanning electron microscopy (SEM), indicating the possible use of this material as a carbon source for its growth.

Actinomycetes in discolored wood of living silver maple

1981 ◽  
Vol 59 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert A. Blanchette ◽  
John B. Sutherland ◽  
Don L. Crawford
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Source ◽  
Cell Walls ◽  
Hydroxybenzoic Acid ◽  
Liquid Media ◽  
Streptomyces Strain ◽  
Culture Techniques ◽  
Silver Maple ◽  
Scanning Electron

The greenish-brown margin of discolored wood in three living silver maple trees, Acer saccharinum L., was examined by scanning electron microscopy and microbiological culture techniques. Micrographs of xylem vessels revealed filamentous structures; some of them appeared to be actinomycetous hyphae. Actinomycetes identified as Streptomyces parvullus Waksman & Gregory, S. sparsogenes Owen, Dietz & Camiener, and a third Streptomyces strain were isolated repeatedly from discolored wood of each tree. These isolates grew in liquid media in the presence of 0.1% (w/v) concentrations of several phenols. Although other phenols included in the test were not substantially degraded, p-hydroxybenzoic acid was utilized as a carbon source by S. parvullus. All three actinomycetes inhibited growth of selected wood-inhabiting fungi when paired on malt agar. When inoculated on sterilized sapwood and discolored wood from silver maple, the actinomycetes colonized vessel walls and occlusions, but were not observed to decay cell walls.

Taxonomic Identification of Rhabdochona Species Found in Oncorhynchus Clarki Using Scanning Electron Microscopy

1998 ◽  
Vol 4 (S2) ◽  
pp. 1148-1149
Author(s):  
D. Young ◽  
R.A. Heckmann ◽  
J. S. Gardner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digestive Tract ◽  
Cutthroat Trout ◽  
Parasitic Nematodes ◽  
Buffer System ◽  
Taxonomic Identification ◽  
Critical Point Drying ◽  
Cacodylate Buffer ◽  
Scanning Electron

Adult Rhabdochona nematodes, commonly parasitizing fish, were present in the digestive tracts of cutthroat trout in Little Cottonwood Creek, Utah. Cutthroat trout, Oncorhyncus clarki, are known to serve as both intermediate and definitive hosts for parasitic nematodes. The larval stage parasitizes almost any tissue of its host, but the adult is always found in the digestive tract. Due to the lack of key morphological features, scanning electron microscopy (SEM) was used to identify specific structures leading to the nematode's taxonomic identification.Cutthroat trout were obtained using a rod and reel and were dissected the same day. Nematodes were present in all 12 cutthroat trout residing in all parts of the digestive tract. The nematodes, Rhabdochona sp., were prepared for SEM using the following procedures. First, the parasites were fixed in 2% buffered glutaraldehyde, washed in sodium cacodylate buffer, and post fixed in a 1% solution of osmium tetroxide. The samples were then washed in the same buffer system and dehydrated through a graded alcohol series. Critical-point-drying removed the remaining fluids. Finally, the nematodes were placed on specimen stubs, sputter coated with gold, and each specimen examined with a JOEL-840 high resolution scanning electron microscope with micrographs taken at varying magnifications.

Natural weather ageing of starch/polyvinyl alcohol blend: effect of glycerol content

2013 ◽  
Vol 33 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Sreekumar Parambathmadhom Appu ◽  
Sadhan Kumar De ◽  
Massihullah J. Khan ◽  
Mamdouh A. Al-Harthi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Weather Conditions ◽  
Intermolecular Hydrogen Bonding ◽  
Biodegradable Material ◽  
Glycerol Content ◽  
Fourier Transfer Infrared Spectroscopy ◽  
Scanning Electron

Abstract Starch plasticized with glycerol and blended with polyvinyl alcohol (PVA) is recommended for use as a biodegradable material. The present article reports the results of studies of the natural weather ageing of starch/PVA blends having various amounts of glycerol in natural weather conditions of Saudi Arabia, with special reference to morphology and thermal behavior. Neat PVA has been used as a control to understand its behavior in its blend with starch. Differential scanning calorimeter studies indicated that an increase in the exposure time of samples to natural environment increases the crystallinity of PVA due to the breakage of intermolecular hydrogen bonding, thus facilitating the removal of the amorphous portion of the polymers in the blend. Thermogravimetric analysis revealed that an increase in glycerol content enhanced the degradation of the polymer, which is corroborated with the findings from the surface morphology using scanning electron microscopy and Fourier transfer infrared spectroscopy analyses.

Scanning electron microscopy of the digestive tract of larval Simulium ornatum Meigen (Complex) (Diptera: Simuliidae) and its associated microbial flora

1995 ◽  
Vol 73 (9) ◽  
pp. 1640-1646 ◽  
Author(s):  
Mark R. Taylor ◽  
Stephen T. Moss ◽  
Mike Ladle
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digestive Tract ◽  
Freeze Fracture ◽  
Microbial Flora ◽  
Peritrophic Membrane ◽  
Filamentous Bacteria ◽  
Direct Observations ◽  
Dissection Technique ◽  
Scanning Electron

The structure and microbial flora of the digestive tract of larval Simulium ornatum were investigated using scanning electron microscopy. Direct observations of the microbial communities associated with the endoperitrophic surface of the peritrophic membrane and the endocuticular surface of the hindgut are presented. The endoperitrophic surface was frequently devoid of bacteria, although the fungus Harpella melusinae (Harpellales, Trichomycetes) was commonly attached. Rarely, spirochaetes and coccoid bacteria were attached to the endoperitrophic surface. In contrast, the endocuticular surface was regularly colonized by a diverse microflora composed of rod-shaped, coccoid, spiral, and filamentous bacteria and two species of Harpellales (Trichomycetes). A freeze-fracture technique is compared with a dissection technique for exposing the endoperitrophic and endocuticular surfaces of the digestive tract.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

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.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

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.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

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).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

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.

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