scholarly journals Microscope methods for observation of the phylloplane flora

2010 ◽  
Vol 63 ◽  
pp. 15-23
Author(s):  
I.C. Hallett ◽  
K.S.H. Boyd-Wilson ◽  
K.R. Everett
Keyword(s):  
Dna Analysis ◽  
Leaf Surface ◽  
Distribution Patterns ◽  
Microbial Populations ◽  
Physical Change ◽  
Microbial Distribution ◽  
Accurate Picture ◽  
Microbial Number ◽  
Environmental Sem ◽  
Scanning Electron

Microscopebased observation of surface microbes can support indirect techniques such as culturing or DNA analysis of surface washings by illustrating microbial distribution patterns interrelationships and the presence of unculturable or nonrecovered organisms Comparisons have been made between techniques of contrasting complexity For example surface replicas of the leaf made from transparent materials and scanning electron microscopy (SEM) were compared for their ability to present an accurate picture of the leaf surface and microbial populations Environmental SEM (ESEM) and cryoSEM minimise change and provide the most realistic and detailed images of the surface but have logistical difficulties Conventional critical point dried SEM samples even with extra processing and some physical change usually provided similar results and had advantages in handling The simpler replica techniques retained microbial number and distribution when compared to ESEM but were poor with rough surfaces Microbial material on replicas could be stained or labelled with antibodies to improve identification

Halamphora oceanica (Catenulaceae, Bacillariophyta), a new species from the epipelagic region of the southwestern Gulf of Mexico

Phytotaxa ◽  
2017 ◽  
Vol 317 (3) ◽  
pp. 188 ◽  
Author(s):  
HUGO F. OLIVARES-RUBIO ◽  
LIDIA I. CABRERA ◽  
JOSÉ LUIS GODÍNEZ-ORTEGA ◽  
LUCÍA SALAZAR-CORIA ◽  
ARMANDO VEGA-LÓPEZ
Keyword(s):  
New Species ◽  
Gulf Of Mexico ◽  
Dna Analysis ◽  
Small Subunit ◽  
Live Cells ◽  
Morphometric Characteristics ◽  
Pennate Diatom ◽  
Microbiological Techniques ◽  
A New Species ◽  
Scanning Electron

In the oceanic zones of the Gulf of Mexico a new species of diatom was found belonging to the genus Halamphora. Live cells were isolated using basic microbiological techniques for culturing and DNA analysis. Observations to determine morphological and morphometric characteristics were performed by both light and scanning electron microscopy. In addition, a phylogeny was built based on the expression and sequencing of the small subunit of the 18S gene. As a result of these observations, we conclude that this pennate diatom is a new species here proposed as Halamphora oceanica.

scholarly journals Vineyard ecosystems are structured and distinguished by fungal communities impacting the flavour and quality of wine

2019 ◽  
Author(s):  
Di Liu ◽  
Qinglin Chen ◽  
Pangzhen Zhang ◽  
Deli Chen ◽  
Kate S. Howell
Keyword(s):  
Regional Distribution ◽  
Distribution Patterns ◽  
Wine Fermentation ◽  
Fungal Communities ◽  
Soil Microbiome ◽  
Soil Conditions ◽  
Wine Aroma ◽  
Wine Production ◽  
Microbial Distribution

AbstractThe flavours of foods and beverages are formed by the agricultural environment where the plants are grown. In the case of wine, the location and environmental features of the vineyard site imprint the wine with distinctive aromas and flavours. Microbial growth and metabolism play an integral role in wine production from the vineyard to the winery, by influencing grapevine health, wine fermentation, and the flavour, aroma and quality of finished wines. The mechanism by which microbial distribution patterns drive wine metabolites is unclear and while flavour has been correlated with bacterial composition for red wines, bacterial activity provides a minor biochemical conversion in wine fermentation. Here, we collected samples across six distinct winegrowing areas in southern Australia to investigate regional distribution patterns of both fungi and bacteria and how this corresponds with wine aroma compounds. Results show that soil and must microbiota distinguish winegrowing regions and are related to wine chemical profiles. We found a strong relationship between microbial and wine metabolic profiles, and this relationship was maintained despite differing abiotic drivers (soil properties and weather/ climatic measures). Notably, fungal communities played the principal role in shaping wine aroma profiles and regional distinctiveness. We found that the soil microbiome is a potential source of grape- and must-associated fungi, and therefore the weather and soil conditions could influence the wine characteristics via shaping the soil fungal community compositions. Our study describes a comprehensive scenario of wine microbial biogeography in which microbial diversity responds to surrounding environments and ultimately sculpts wine aromatic characteristics. These findings provide perspectives for thoughtful human practices to optimise food and beverage flavour and composition through understanding of fungal activity and abundance.

Novel and Advanced Applications of the Low Vacuum and Environmental Scanning Electron Microscope (SEM)

1997 ◽  
Vol 3 (S2) ◽  
pp. 385-386 ◽  
Author(s):  
Brendan J. Griffin
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Secondary Electron ◽  
Electron Gun ◽  
Environmental Scanning ◽  
Electron Detector ◽  
Environmental Sem ◽  
Practical Sense ◽  
Advanced Applications ◽  
Scanning Electron

The environmental SEM is an extremely adaptive instrument, allowing a range of materials to be examined under a wide variety of conditions. The limitations of the instrument lie mainly with the restrictions imposed by the need to maintain a moderate vacuum around the electron gun. The primary effect of this has been, in a practical sense, the limited low magnification available. Recently this has been overcome by modifications to the final pressure limiting aperture and secondary electron detector (Fig.l). The modifications are simple and users should be brave in this regard.A variety of electron detectors now exist including various secondary, backscattered and cathodoluminescence systems (Figs 2-5). These provide an excellent range of options; the ESEM must be regarded as a conventional SEM in that a range of imaging options should be installed. In some cases, e.g. cathodoluminescence, the lack of coating provides an advantage unique to the low vacuum SEMs.

Herbicide Dispersal Patterns: HI. as a Function of Formulation

Weed Science ◽  
1981 ◽  
Vol 29 (2) ◽  
pp. 224-229 ◽  
Author(s):  
F. D. Hess ◽  
D. E. Bayer ◽  
R. H. Falk
Keyword(s):  
Sugar Beet ◽  
Cell Walls ◽  
Cynodon Dactylon ◽  
Distribution Patterns ◽  
Dispersal Patterns ◽  
Commercial Formulation ◽  
X Ray ◽  
Leaf Surfaces ◽  
Wettable Powder ◽  
Scanning Electron

The distribution patterns of several herbicide formulations sprayed on adaxial leaf surfaces were determined using scanning electron microscopy coupled with cathodoluminescence and x-ray microanalysis. The sodium and amine salts of MCPA {[(4-chloro-o-tolyl) oxy] acetic acid} sprayed on sugar beet (Beta vulgarisL.) leaves appeared as discrete deposits above the anticlinal cell walls that represented the location of spray drops that adhered to the leaf. When the sodium salt was applied to bermudagrass [Cynodon dactylon(L.) Pers.], the pattern of distribution was the same; however, each deposit was significantly smaller. The iso-octyl ester of MCPA coalesced into numerous, small, thick deposits on the cuticle of sugar beet leaves. The distribution of a wettable powder formulation of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino-s-triazine] appeared as uniform deposits over the anticlinal and periclinal cell walls that represented the location of aqueous spray drops after application. When a flowable formulation of atrazine was applied, there was a significant preferential accumulation of the herbicide at the edges of the separate deposits. One commercial formulation of propanil (3′,4′-dichloropropionanilide) yielded deposits that were crystalline, one that was partially crystalline, and one that was noncrystalline.

X-Ray Energy Dispersive Spectroscopy in the Environmental Scanning Electron Microscope

1998 ◽  
Vol 4 (S2) ◽  
pp. 182-183
Author(s):  
John F. Mansfield ◽  
Brett L. Pennington
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive Spectroscopy ◽  
Primary Electron ◽  
Environmental Scanning ◽  
Primary Electron Beam ◽  
X Ray ◽  
Environmental Sem ◽  
Scanning Electron

The environmental scanning electron microscope (Environmental SEM) has proved to be a powerful tool in both materials science and the life sciences. Full characterization of materials in the environmental SEM often requires chemical analysis by X-ray energy dispersive spectroscopy (XEDS). However, the spatial resolution of the XEDS signal can be severely degraded by the gaseous environment in the sample chamber. At an operating pressure of 5Torr a significant fraction of the primary electron beam is scattered after it passes through the final pressure limiting aperture and before it strikes the sample. Bolon and Griffin have both published data that illustrates this effect very well. Bolon revealed that 45% of the primary electron beam was scattered by more than 25 μm in an Environmental SEM operating at an accelerating voltage of 30kV, with a water vapor pressure of 3Torr and a working distance of 15mm.

scholarly journals Foliar epidermis morphology in Quercus (subgenus Quercus, section Quercus) in Iran

2012 ◽  
Vol 71 (1) ◽  
pp. 95-113 ◽  
Author(s):  
Parisa Panahi ◽  
Ziba Jamzad ◽  
Mohammad Pourmajidian ◽  
Asghar Fallah ◽  
Mehdi Pourhashemi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Statistical Analysis ◽  
Leaf Surface ◽  
Epicuticular Waxes ◽  
Abaxial Leaf Surface ◽  
Trichome Types ◽  
Foliar Morphology ◽  
Scanning Electron ◽  
Foliar Epidermis

Foliar epidermis morphology inQuercus(subgenusQuercus, sectionQuercus) in IranThe foliar morphology of trichomes, epicuticular waxes and stomata inQuercus cedrorum, Q. infectoriasubsp.boissieri, Q. komarovii, Q. longipes, Q. macranthera, Q. petraeasubsp.ibericaandQ. robursubsp.pedunculiflorawere studied by scanning electron microscopy. The trichomes are mainly present on abaxial leaf surface in most species, but rarely they appear on adaxial surface. Five trichome types are identified as simple uniseriate, bulbous, solitary, fasciculate and stellate. The stomata of all studied species are of the anomocytic type, raised on the epidermis. The stomata rim may or may not be covered with epicuticular. The epicuticular waxes are mostly of the crystalloid type but smooth layer wax is observed inQ. robursubsp.pedunculiflora.Statistical analysis revealed foliar micromorphological features as been diagnostic characters inQuercus.

Environmental SEM in a Multi-User Biological Sciences E.M. Unit

1999 ◽  
Vol 5 (S2) ◽  
pp. 286-287
Author(s):  
Christopher J. Gilpin ◽  
Mohamed S. Baguneid
Keyword(s):  
Biological Sciences ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Vacuum ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Environmental Sem ◽  
Imaging Mechanisms ◽  
Scanning Electron ◽  
The Ideal

Environmental scanning electron microscopy (ESEM) has matured into a mainstream technique in many areas of microscopy. Instrumentation has evolved and our understanding of some of the imaging mechanisms has progressed. However the majority of laboratories where ESEMs are located are based around the materials sciences. Despite the fact that ESEM is the only SEM instrument that permits liquid water to be present whilst imaging, the housing of such a microscope in biological EM units has been relatively rare. This authors laboratory is a multi-user EM unit based in a School of Biological Sciences. There exists the opportunity for basic biological scientists, clinical and pre-clinical medical and dental researchers to make use of such a resource. Indeed as the ESEM is housed alongside a conventional high vacuum instrument and a cryo high vacuum instrument there exists the ideal opportunity to carry out comparative studies.This study will examine a range of biological samples using ESEM, cryo SEM and dry high vacuum SEM.

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