Fundamental Studies of Bacterial Leaching Using Bio-Physical Techniques of Transmission Electron Microscopy

1975 ◽  
Vol 33 ◽  
pp. 644-645
Author(s):  
V.K. Berry ◽  
L.E. Murr
Keyword(s):  
Bacterial Attachment ◽  
Water Soluble ◽  
Metal Sulfides ◽  
Bacterial Leaching ◽  
Research Areas ◽  
Transmission Electron ◽  
Further Development ◽  
Soluble Sulfates ◽  
Metallurgical Processes

The role of microorganisms and their reaction with minerals are comparatively newer research areas in the general area of chemical mining, and have considerable scope of further development. The most commonly studied reactions of this type have been associated with microorganisms characterized as Thiobacillus thio-oxidans and Thiobacillus ferroxidans. These microorganisms have the ability to oxidize heavy metal sulfides and elemental sulfur to water soluble sulfates; and ferrous iron to ferric iron.The attachment location of biological microorganisms on minerals has not been reported in the literature as it relates specifically to biogenic metallurgical processes, although an attempt to describe the mode and character of bacterial attachment has been made by some workers. In the current investigation, a thermophillic microbe previously described by Brierley and Brierley and suggested to have a relationship with Sulfolobus was used. This microorganism exhibits an intracellular retractile body un-like Sulfolobus.

FISH Analysis of Bacterial Attachment to Copper Sulfides in Bioleaching Processes

2009 ◽  
Vol 71-73 ◽  
pp. 329-332
Author(s):  
J. Huergo ◽  
C. Bernardelli ◽  
M. Viera ◽  
Wolfgang Sand ◽  
Edgardo R. Donati
Keyword(s):  
Cell Attachment ◽  
Sulfide Oxidation ◽  
Metal Sulfide ◽  
Bacterial Attachment ◽  
Water Soluble ◽  
Soluble Form ◽  
Metal Sulfides ◽  
Fish Analysis ◽  
Acidithiobacillus Thiooxidans ◽  
Copper Sulfides

Bioleaching is the biological conversion of an insoluble metal compound into a water soluble form. In this process metal sulfides are oxidized to metal ions and sulfate by acidophilic microorganisms capable of oxidizing Fe2+ and/or sulfur-compounds. The metal solubilization from sulfide minerals is a chemical process which requires Fe3+ reduction. It is an environmentally friendly technique and an economical method for recovering metals that requires low investment and operation costs. In this work we studied the bioleaching of two kinds of acid-soluble copper sulfides, one easily leached by mesophilic bacteria (covellite), and the other one refractory to their activity (chalcopyrite), in acidic media with or without Fe2+ ions. We studied attached and planktonic populations of autotrophic bacteria, such as Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans in pure or mixed cultures. The influence of a heterotrophic microorganism, Acidiphilium cryptum, was also studied. Attachment was evaluated with fluorescence staining and FISH using four specific probes. L. ferrooxidans showed highest initial attachment in all cases. The presence of Ap. cryptum increased the cell attachment compared with the autotrophic pure cultures. It was possible to correlate experimental data with a mechanism of bacterial-metal sulfide oxidation, the polysulfide pathway for acid- soluble metal sulfides.

scholarly journals The rumen eukaryotome is a source of novel antimicrobial peptides with therapeutic potential

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lucy A. Onime ◽  
Linda B. Oyama ◽  
Benjamin J. Thomas ◽  
Jurnorain Gani ◽  
Peter Alexander ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Bacterial Infections ◽  
Therapeutic Potential ◽  
Membrane Damage ◽  
Therapeutic Index ◽  
Antimicrobial Activities ◽  
Transmission Electron ◽  
Helical Peptide ◽  
Further Development

Abstract Background The rise of microbial antibiotic resistance is a leading threat to the health of the human population. As such, finding new approaches to tackle these microbes, including development of novel antibiotics is vital. Results In this study, we mined a rumen eukaryotic metatranscriptomic library for novel Antimicrobial peptides (AMPs) using computational approaches and thereafter characterised the therapeutic potential of the AMPs. We identified a total of 208 potentially novel AMPs from the ruminal eukaryotome, and characterised one of those, namely Lubelisin. Lubelisin (GIVAWFWRLAR) is an α-helical peptide, 11 amino acid long with theoretical molecular weight of 1373.76 D. In the presence of Lubelisin, strains of methicillin-resistant Staphylococcus aureus (MRSA) USA300 and EMRSA-15 were killed within 30 min of exposure with ≥103 and 104 CFU/mL reduction in viable cells respectively. Cytotoxicity of Lubelisin against both human and sheep erythrocytes was low resulting in a therapeutic index of 0.43. Membrane permeabilisation assays using propidium iodide alongside transmission electron microscopy revealed that cytoplasmic membrane damage may contribute to the antimicrobial activities of Lubelisin. Conclusions We demonstrate that the rumen eukaryotome is a viable source for the discovery of antimicrobial molecules for the treatment of bacterial infections and further development of these may provide part of the potential solution to the ongoing problem of antimicrobial resistance. The role of these AMPs in the ecological warfare within the rumen is also currently unknown.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

Cognitive Health Counseling 40+

2013 ◽  
Vol 21 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Anne Eschen ◽  
Franzisca Zehnder ◽  
Mike Martin
Keyword(s):  
Outcome Variable ◽  
Pilot Phase ◽  
Subjective Memory ◽  
Cognitive Health ◽  
Health Counseling ◽  
Agents Of Change ◽  
Main Outcome Variable ◽  
Further Development

This article introduces Cognitive Health Counseling 40+ (CH.CO40+), an individualized intervention that is conceptually based on the orchestration model of quality-of-life management ( Martin & Kliegel, 2010 ) and aims at improving satisfaction with cognitive health in adults aged 40 years and older. We describe the theoretically deduced characteristics of CH.CO40+, its target group, its multifactorial nature, its individualization, the application of subjective and objective measures, the role of participants as agents of change, and the rationale for choosing participants’ satisfaction with their cognitive health as main outcome variable. A pilot phase with 15 middle-aged and six older adults suggests that CH.CO40+ attracts, and may be particularly suitable for, subjective memory complainers. Implications of the pilot data for the further development of the intervention are discussed.

Problems and prospects for the Russian banking supervision development in modern conditions

2020 ◽  
Vol 26 (6) ◽  
pp. 1283-1296
Author(s):  
K.A. Omarieva ◽  
P.G. Isaeva
Keyword(s):  
Banking System ◽  
Main Role ◽  
Banking Supervision ◽  
Monetary System ◽  
The Russian Federation ◽  
Document Flow ◽  
Development Methods ◽  
Further Development ◽  
Development Prospects

Subject. The article addresses problems and prospects for the banking supervision development in the Russian Federation under modern conditions. Objectives. We review the essence and methods of organization of the banking supervision, and identify the main problems and prospects for its development. Methods. To provide valid, reliable and reasoned recommendations, we apply normative and integrated approaches to the study of the banking supervision effectiveness in the current circumstances. Results. The paper investigates main problems and development prospects for the Russian banking supervision. The essential importance of supervision comes from the main role of the banking system in maintaining accounts of economic entities and making settlements. Even minor failures or delays in operations can lead to negative outcomes and disastrous consequences for the entire monetary system and the national economy. Therefore, we highlight issues that require attention, and make proposals for further development of the banking supervision. Conclusions. In the context of dynamically developing economy, the banking practice is becoming more complex. As a result, there is a need for new financial instruments that can reduce risks, increase the speed and efficiency of operations and document flow, and help achieve the world levels of introduced standards.

ANALYSIS OF APPLICATION OF BLOCKCHAIN TECHNOLOGIES FOR THE BANKING SECTOR

2017 ◽  
Author(s):  
Svitlana Ilkovych ◽  
◽  
Maryna Korol ◽  
Keyword(s):  
Banking Sector ◽  
Blockchain Technology ◽  
Current State ◽  
Global Banking ◽  
Banking Institutions ◽  
Pros And Cons ◽  
Further Development

The article considers the essence of blockchain technology and the possibility of its application in the banking sector. The current state of development and application of blockchain technologies in various industries is analyzed. The pros and cons of using blockchain technologies for the banking sector are identified. Emphasis is placed on the role of blockchain technologies in the further development of the banking sector. The most promising directions of development of this technology are considered. Particular attention is paid to examples of the use of blockchain technology by global banking institutions.

Sign in / Sign up

Export Citation Format

Share Document