Fine Structure of Bacteria Grown in the Presence of Acriflavine

1968 ◽  
Vol 26 ◽  
pp. 70-71
Author(s):  
Edwin S. Boatman
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Yeast Extract ◽  
Bacterial Growth ◽  
Bacterial Species ◽  
The Other ◽  
Yeast Extract Medium ◽  
Peptone Water ◽  
Extract Medium

The effect of acridine derivatives on bacterial growth has been shown to be dependent upon the concentration used, pH, temperature, and the position of the amino substituents on the acridine molecule. These factors, in turn, affect the amount of acridine bound to cell constituents. Many bacterial species, when grown in media containing acridities, become filamentous, or pleomorphic, or growth may be entirely prevented. The fine-structure of two species of bacteria treated with acriflavine was investigated. Both were Gram-positive bacilli, one was a Corynebacterium, and the other an aerobic spore-bearing Bacillus.Organisms were incubated at 21°c in the presence of concentrations of acriflavine ranging from 0.25 ug/ml to 12 ug/ml in phosphate buffered peptone water yeast extract medium at pH 7.5. Viable counts were carried out and the amount of acriflavine bound, either reversibly or irreversibly, was estimated at 450 mu, using a DB spectrophotometer. Cultures were observed by light microscopy and, after four days growth, were processed for electron microscopy by fixation in veronal-acetate pH 6.1 buffered 0.8% Os O4 for one hour and embedding in Epon 812 resin.

Factors affecting the production of hydrogenase by Desulfovibrio desulfuricans

1980 ◽  
Vol 26 (10) ◽  
pp. 1209-1213 ◽  
Author(s):  
S. M. Martin ◽  
B. R. Glick ◽  
W. G. Martin
Keyword(s):  
Ammonium Sulfate ◽  
Yeast Extract ◽  
Desulfovibrio Desulfuricans ◽  
The Other ◽  
Hydrogenase Activity ◽  
Factors Affecting ◽  
Yeast Extract Medium ◽  
Extract Medium ◽  
Culture Development

An examination of conditions for the growth of Desulfovibrio desulfuricans, with the aim of optimizing hydrogenase production, is reported. An ammonium sulfate – lactate – yeast extract medium gave 5 to 10 times as much hydrogenase activity as a peptone – yeast extract medium. It made little if any difference whether the gas used for sparging was nitrogen, hydrogen, or a mixture thereof but increasing the rate of sparging and agitation did result in a slight decrease in activity. Control of pH during culture development was of little benefit to hydrogenase production. At least two hydrogenases were present in D. desulfuricans: one periplasmic, the other membrane bound.Desulfovibrio desulfuricans produced more hydrogenase than did either D. gigas and D. vulgaris.

scholarly journals Selection ofStaphylococcus aureusin cultures from air samples

1969 ◽  
Vol 67 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Lynn Harding ◽  
R. E. O. Williams
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Research ◽  
Yeast Extract ◽  
Good Yield ◽  
The Other ◽  
Airborne Bacteria ◽  
Ministry Of Health ◽  
Air Samples ◽  
Yeast Extract Medium ◽  
Extract Medium

SUMMARYA tryptone-yeast extract medium enriched with glucose and serum incubated anaerobically at 41° C. was found to give a good yield ofStaphylococcus aureusfrom air samples while suppressing the growth of 70–80% of the other airborne bacteria.Our thanks are due to Miss S. M. Taber and Miss Patricia Wall, the Sisters in the wards where the air samples were collected, for their help. The investigation was financed from the Ministry of Health grant to St Mary's Hospital for the support of clinical research.

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).

Comparative strengths and weaknesses of peroxidase and colloidal gold in pre- and post-embedding immunolabeling techniques

1987 ◽  
Vol 45 ◽  
pp. 1002-1005
Author(s):  
D. R. Abrahamson ◽  
P. L. St.John ◽  
E. W. Perry
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Light Microscopy ◽  
Colloidal Gold ◽  
Light Microscope ◽  
Ultrastructural Localization ◽  
The Other ◽  
Quantitative Studies ◽  
Dense Suspension ◽  
Antigen Localization

Antibodies coupled to tracers for electron microscopy have been instrumental in the ultrastructural localization of antigens within cells and tissues. Among the most popular tracers are horseradish peroxidase (HRP), an enzyme that yields an osmiophilic reaction product, and colloidal gold, an electron dense suspension of particles. Some advantages of IgG-HRP conjugates are that they are readily synthesized, relatively small, and the immunolabeling obtained in a given experiment can be evaluated in the light microscope. In contrast, colloidal gold conjugates are available in different size ranges and multiple labeling as well as quantitative studies can therefore be undertaken through particle counting. On the other hand, gold conjugates are generally larger than those of HRP but usually can not be visualized with light microscopy. Concern has been raised, however, that HRP reaction product, which is exquisitely sensitive when generated properly, may in some cases distribute to sites distant from the original binding of the conjugate and therefore result in spurious antigen localization.

Isolation and identification of N2-fixing Pseudomonas associated with wetland rice

1983 ◽  
Vol 29 (8) ◽  
pp. 867-873 ◽  
Author(s):  
W. L. Barraquio ◽  
J. K. Ladha ◽  
I. Watanabe
Keyword(s):  
New Species ◽  
Yeast Extract ◽  
Heterotrophic Bacteria ◽  
Fluorescent Antibody ◽  
Wetland Rice ◽  
Isolation And Identification ◽  
Biochemical Characteristics ◽  
Yeast Extract Medium ◽  
Extract Medium ◽  
A New Species

Semisolid yeast extract medium amended with glucose and tryptic soy agar were used to isolate aerobically N2-fixing (C2H2-reducing) heterotrophic bacteria from the root of wetland rice. The isolates were identified as Pseudomonas by gel immunodiffusion and fluorescent antibody techniques in combination with their morphological, cultural, and biochemical characteristics. The N2-fixing H2-utilizing Pseudomonas described in this paper is a new species.

STRAIN IMPROVEMENT OF A FUNGUS PRODUCING CHITINASE BY A CHEMICAL MUTAGEN

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (11) ◽  
pp. 25-28
Author(s):  
K Narayanan ◽  
◽  
N.D. Chopade ◽  
V.M Subrahmanyam ◽  
J. Venkata Rao
Keyword(s):  
Protein Content ◽  
Ethidium Bromide ◽  
Yeast Extract ◽  
Wild Strain ◽  
Strain Improvement ◽  
Cost Effective ◽  
Specific Protein ◽  
Chemical Mutagen ◽  
Yeast Extract Medium ◽  
Extract Medium

Microbial chitinases are commercially exploited for their biocontrol properties and generation of useful products from chitinous waste. Availability of highly active chitinolytic enzymes is a major problem. The present study was carried out to improve chitinase production by Aspergillus terreus using a chemical mutagen, ethidium bromide. The organism was cultivated on lactose- yeast extract medium. The production medium consisting of chitin- yeast extract medium was seeded at 10% level. The wild strains were exposed to ethidium bromide in the concentration range 1.5- 6.0 µg/mL. Generally, all the mutated strains showed an improved chitinase yield compared to the control. Highest yield was observed with the strain exposed to 6 µg/mL of ethidium bromide. The yield was 25.03 % higher compared to the wild strain. The mutated strain was slimy in nature. Protein content of the mutated strain decreased by 11%. Ethidium bromide at a concentration of 1.5 µg/mL was considered optional, at which the strain was stable with increase of 21.80 % in enzyme activity and 4.41% increase in protein content. Increased enzyme yield with decreased non-specific protein could be useful in producing cost effective enzyme.

scholarly journals VARIATIONS IN THE STRUCTURE OF MITOCHONDRIA

1956 ◽  
Vol 2 (4) ◽  
pp. 305-312 ◽  
Author(s):  
E. W. Dempsey
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Internal Structure ◽  
Outer Wall ◽  
The Other ◽  
Metabolic Processes ◽  
Intracellular Membranes ◽  
Janus Green ◽  
Definition Of ◽  
Shape Complexity

A characteristic internal structure, consisting of a double-layered outer wall enclosing a matrix-filled space through which pass double-layered membranous folds, would appear to comprise as satisfactory a definition of mitochondria for electron microscopy as their intravital affinity for Janus green affords for light microscopy. Relying for identification upon this characteristic internal structure, mitochondria appear to be pleomorphic structures which vary in size, shape, complexity, and density. They are labile also in that their number may increase or decrease under controlled conditions. The possibility therefore exists that these organelles are constantly being formed and destroyed, perhaps by their participation in metabolic processes. The problem of the origin of mitochondria is in an unsatisfactory state. New organelles unquestionably are formed in particular physiological states. The possibility that new bodies are produced by fission of ones already present does not seem adequate. On the other hand, the possible fabrication of new mitochondria out of intracellular membranes, although an attractive hypothesis, has not been adequately substantiated.

Problems associated with ageing squid from their statoliths: towards a more structured approach

1994 ◽  
Vol 6 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Marek R. Lipinski ◽  
M. Deon Durholtz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Regression Analysis ◽  
Light Microscopy ◽  
The Other ◽  
Etching Solution ◽  
Significant Difference ◽  
Structured Approach ◽  
Fish Otoliths ◽  
Scanning Electron

It appears that squid statoliths cannot yet be regarded as accurate an ageing tool as fish otoliths. Statoliths from the same pair, prepared differently for viewing and counting increments, were compared. Increment counts do not imply age in days, because this was not validated. One statolith from each pair was examined by light microscopy (LM) after preparation following a new method. The other was viewed by Scanning Electron microscopy (SEM) with a modified etching solution. Shape of each statolith was similar when compared by multiple regression analysis (11 variables, n=53). There was a weak but significant difference between sexes (statoliths of females were slightly larger). All other differences were insignificant. Microscopic observation and increment counts of increments were successfully carried out for 37 pairs of statoliths. Significant differences between two independent counts were found for the LM method, but no significant differences were found between two independent SEM counts. Counts were significantly different when interpreted by both LM and SEM, probably because of poor resolution in the LM readings and over-resolution (growth layers prominent and numerous) in those read by SEM. Recommendations are made on how ageing studies, based on statoliths, should be structured and the results evaluated.

Pollen morphology of Sabinaria magnifica (Cryosophileae, Coryphoideae, Arecaceae)

Phytotaxa ◽  
2015 ◽  
Vol 207 (1) ◽  
pp. 135 ◽  
Author(s):  
Giovanni Raul Bogota ◽  
Carina Hoorn ◽  
Wim Star ◽  
Rob Langelaan ◽  
Hannah Banks ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
The Other ◽  
Transmission Electron ◽  
Palm Species ◽  
Scanning Electron

Sabinaria magnifica is so far the only known species in the recently discovered tropical palm genus Sabinaria (Arecaceae). Here we present a complete description of the pollen morphology of this palm species based on light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We also made SEM-based comparisons of Sabinaria with other genera within the tribe Cryosophileae. Pollen grains of Sabinaria magnifica resemble the other genera in the heteropolar, slightly asymmetric monads, and the monosulcate and tectate exine with perforate surface. Nevertheless, there are some clear differences with Thrinax, Chelyocarpus and Cryosophila in terms of aperture and exine. S. magnifica differs from its closest relative, Itaya amicorum, in the exine structure. This study shows that a combination of microscope techniques is essential for the identification of different genera within the Cryosophileae and may also be a necessary when working with other palynologically less distinct palm genera. 

Fine Structure of the Eye of a Nudibranch Mollusc, Hermissenda Crassicornis

1967 ◽  
Vol 2 (3) ◽  
pp. 349-358
Author(s):  
R. M. EAKIN ◽  
JANE A. WESTFALL ◽  
M. J. DENNIS
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Optic Nerve ◽  
Light And Electron Microscopy ◽  
The Other ◽  
Sensory Cells ◽  
Nerve Fibres ◽  
Supporting Cells ◽  
Small Bodies ◽  
Receptor Cells

The eye of a nudibranch, Hermissenda crassicornis, was studied by light and electron microscopy. Three kinds of cells were observed: large sensory cells, each bearing at one end an array of microvilli (rhabdomere) and at the other end an axon which leaves the eye by the optic nerve; large pigmented supporting cells; and small epithelial cells, mostly corneal. There are five sensory cells, and the same number of nerve fibres in the optic nerve. The receptor cells contain an abundance of small vesicles, 600-800 Å in diameter. The lens is a spheroidal mass of osmiophilic, finely granular material. A basal lamina and a capsule of connective tissue enclose the eye. In some animals the eye is ‘infected’ with very small bodies, 4-5 µ in diameter, thought to be symbionts.

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