Cell Structure and Function in the Bacteria and Archaea
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Cephalobus Litoralis: Biology and Tolerance to Desiccation
Journal of Nematology 20(2):327-329. 1988. © The Society of Nematologists 1988. Cephalobus litorali . Biology and Tolerance to Desiccation M. SAEED, S. A. KHAN, V. A. SAEED, AND H. A. KHAN1 Abstract: Cephalobus litoralis (Akhtar, 1962) Andr~ssy, 1984 reproduced parthenogenetically and completed its life cycle in 72-90 hours. Each female deposited 200-300 eggs. The nematodes showed synchronized movements in the rhythms of the anterior parts of the body. The nematodes were coiled when dried in culture medium or in slowly evaporating water droplets on the tops of culture plates, but in pellets they assumed irregular postures. Nematodes in pellets stored at high humidity could be reactivated after storage for 28 days. Key words: behavior, Cephalobus litoralis, coiling, desiccation tolerance, life cycle, parthenogenesis, synchronized movement. Cephalobus litoralis (Akhtar) Andrfissy, by a modified Baermann funnel method. 1984 was described in 1962 by Akhtar (1) A single gravid female was placed in a cav- as Paracephalobus litoralis based on only two ity slide containing water. After oviposi- female specimens collected from soil tion, a single egg was transferred to a petri around the roots of sugarcane (Saccharum dish containing finely blended pea meal o~cinarum L.) in the agricultural farms of paste (PMP) and water. All experiments the Pakistan Council of Scientific and In- were conducted with nematodes from sin- dustrial Research (PCSIR), Lahore, Paki- gle egg progeny raised in this manner. stan. It had not been reported elsewhere For mass rearing, nematodes were cul- until the authors found it in Karachi. In tured in 14-cm-d petri dishes containing 1967 Andrfissy (3) transferred Eucephalo- pea meal paste. -
Glossary - Cellbiology
1 Glossary - Cellbiology Blotting: (Blot Analysis) Widely used biochemical technique for detecting the presence of specific macromolecules (proteins, mRNAs, or DNA sequences) in a mixture. A sample first is separated on an agarose or polyacrylamide gel usually under denaturing conditions; the separated components are transferred (blotting) to a nitrocellulose sheet, which is exposed to a radiolabeled molecule that specifically binds to the macromolecule of interest, and then subjected to autoradiography. Northern B.: mRNAs are detected with a complementary DNA; Southern B.: DNA restriction fragments are detected with complementary nucleotide sequences; Western B.: Proteins are detected by specific antibodies. Cell: The fundamental unit of living organisms. Cells are bounded by a lipid-containing plasma membrane, containing the central nucleus, and the cytoplasm. Cells are generally capable of independent reproduction. More complex cells like Eukaryotes have various compartments (organelles) where special tasks essential for the survival of the cell take place. Cytoplasm: Viscous contents of a cell that are contained within the plasma membrane but, in eukaryotic cells, outside the nucleus. The part of the cytoplasm not contained in any organelle is called the Cytosol. Cytoskeleton: (Gk. ) Three dimensional network of fibrous elements, allowing precisely regulated movements of cell parts, transport organelles, and help to maintain a cell’s shape. • Actin filament: (Microfilaments) Ubiquitous eukaryotic cytoskeletal proteins (one end is attached to the cell-cortex) of two “twisted“ actin monomers; are important in the structural support and movement of cells. Each actin filament (F-actin) consists of two strands of globular subunits (G-Actin) wrapped around each other to form a polarized unit (high ionic cytoplasm lead to the formation of AF, whereas low ion-concentration disassembles AF). -
Modelling Panspermia in the TRAPPIST-1 System
October 13, 2017 Modelling panspermia in the TRAPPIST-1 system James A. Blake1,2*, David J. Armstrong1,2, Dimitri Veras1,2 Abstract The recent ground-breaking discovery of seven temperate planets within the TRAPPIST-1 system has been hailed as a milestone in the development of exoplanetary science. Centred on an ultra-cool dwarf star, the planets all orbit within a sixth of the distance from Mercury to the Sun. This remarkably compact nature makes the system an ideal testbed for the modelling of rapid lithopanspermia, the idea that micro-organisms can be distributed throughout the Universe via fragments of rock ejected during a meteoric impact event. We perform N-body simulations to investigate the timescale and success-rate of lithopanspermia within TRAPPIST-1. In each simulation, test particles are ejected from one of the three planets thought to lie within the so-called ‘habitable zone’ of the star into a range of allowed orbits, constrained by the ejection velocity and coplanarity of the case in question. The irradiance received by the test particles is tracked throughout the simulation, allowing the overall radiant exposure to be calculated for each one at the close of its journey. A simultaneous in-depth review of space microbiological literature has enabled inferences to be made regarding the potential survivability of lithopanspermia in compact exoplanetary systems. 1Department of Physics, University of Warwick, Coventry, CV4 7AL 2Centre for Exoplanets and Habitability, University of Warwick, Coventry, CV4 7AL *Corresponding author: [email protected] Contents Universe, and can propagate from one location to another. This interpretation owes itself predominantly to the works of William 1 Introduction1 Thompson (Lord Kelvin) and Hermann von Helmholtz in the 1.1 Mechanisms for panspermia...............2 latter half of the 19th Century. -
The Influence of Probiotics on the Firmicutes/Bacteroidetes Ratio In
microorganisms Review The Influence of Probiotics on the Firmicutes/Bacteroidetes Ratio in the Treatment of Obesity and Inflammatory Bowel disease Spase Stojanov 1,2, Aleš Berlec 1,2 and Borut Štrukelj 1,2,* 1 Faculty of Pharmacy, University of Ljubljana, SI-1000 Ljubljana, Slovenia; [email protected] (S.S.); [email protected] (A.B.) 2 Department of Biotechnology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia * Correspondence: borut.strukelj@ffa.uni-lj.si Received: 16 September 2020; Accepted: 31 October 2020; Published: 1 November 2020 Abstract: The two most important bacterial phyla in the gastrointestinal tract, Firmicutes and Bacteroidetes, have gained much attention in recent years. The Firmicutes/Bacteroidetes (F/B) ratio is widely accepted to have an important influence in maintaining normal intestinal homeostasis. Increased or decreased F/B ratio is regarded as dysbiosis, whereby the former is usually observed with obesity, and the latter with inflammatory bowel disease (IBD). Probiotics as live microorganisms can confer health benefits to the host when administered in adequate amounts. There is considerable evidence of their nutritional and immunosuppressive properties including reports that elucidate the association of probiotics with the F/B ratio, obesity, and IBD. Orally administered probiotics can contribute to the restoration of dysbiotic microbiota and to the prevention of obesity or IBD. However, as the effects of different probiotics on the F/B ratio differ, selecting the appropriate species or mixture is crucial. The most commonly tested probiotics for modifying the F/B ratio and treating obesity and IBD are from the genus Lactobacillus. In this paper, we review the effects of probiotics on the F/B ratio that lead to weight loss or immunosuppression. -
Bacterial Cell Membrane
BACTERIAL CELL MEMBRANE Dr. Rakesh Sharda Department of Veterinary Microbiology NDVSU College of Veterinary Sc. & A.H., MHOW CYTOPLASMIC MEMBRANE ➢The cytoplasmic membrane, also called a cell membrane or plasma membrane, is about 7 nanometers (nm; 1/1,000,000,000 m) thick. ➢It lies internal to the cell wall and encloses the cytoplasm of the bacterium. ➢It is the most dynamic structure of a prokaryotic cell. Structure of cell membrane ➢The structure of bacterial plasma membrane is that of unit membrane, i.e., a fluid phospholipid bilayer, composed of phospholipids (40%) and peripheral and integral proteins (60%) molecules. ➢The phospholipids of bacterial cell membranes do not contain sterols as in eukaryotes, but instead consist of saturated or monounsaturated fatty acids (rarely, polyunsaturated fatty acids). ➢Many bacteria contain sterol-like molecules called hopanoids. ➢The hopanoids most likely stabilize the bacterial cytoplasmic membrane. ➢The phospholipids are amphoteric molecules with a polar hydrophilic glycerol "head" attached via an ester bond to two non-polar hydrophobic fatty acid tails. ➢The phospholipid bilayer is arranged such that the polar ends of the molecules form the outermost and innermost surface of the membrane while the non-polar ends form the center of the membrane Fluid mosaic model ➢The plasma membrane contains proteins, sugars, and other lipids in addition to the phospholipids. ➢The model that describes the arrangement of these substances in lipid bilayer is called the fluid mosaic model ➢Dispersed within the bilayer are various structural and enzymatic proteins, which carry out most membrane functions. ➢Some membrane proteins are located and function on one side or another of the membrane (peripheral proteins). -
Structural and Functional Characterization of the Fimh Adhesin of Uropathogenic Escherichia Coli and Its Novel Applications
Open Access Journal of Bacteriology and Mycology Research Article Structural and Functional Characterization of the FimH Adhesin of Uropathogenic Escherichia coli and Its Novel Applications Neamati F1, Moniri R2*, Khorshidi A1 and Saffari M1 Abstract 1Department of Microbiology and Immunology, School Type 1 fimbriae are responsible for bacterial pathogenicity and biofilm of Medicine, Kashan University of Medical Sciences, production, which are important virulence factors in uropathogenic Escherichia Kashan, Iran coli strains. Many articles are published on FimH, but each examined a specific 2Department of Microbiology, Faculty of Medicine, aspect of this protein. The current review study aimed at focusing on structure Kashan University of Medical Sciences, Qutb Ravandi and conformational changes and describing efforts to use this protein in novel Boulevard, Kashan, Iran potential treatments for urinary tract infections, typing methods, and expression *Corresponding author: Moniri R, Department of systems. The current study was the first review that briefly and effectively Microbiology, Faculty of Medicine, Kashan University of examined issues related to FimH adhesin. Medical Sciences, Qutb Ravandi Boulevard, Kashan, Iran Keywords: Uropathogenic E. coli; FimH Adhesion; FimH Typing; Received: June 05, 2020; Accepted: July 03, 2020; Conformation Switch; FimH Antagonists Published: July 10, 2020 Abbreviations FimH proteins play important roles in UPEC pathogenicity and the formation of bacterial biofilms [7]. FimH binds to mannosylated UTIs: Urinary Tract Infections; UPEC: Uropathogenic E. uroplakin proteins in the bladder lumen and invades into the Coli; IBCs: Intracellular Bacterial Communities; QIR: Quiescent superficial umbrella cells [8]. After the invasion, UPEC is expelled out Intracellular Reservoir; LD: Mannose-Binding Lectin; PD: Fimbria- of the cell in a TLR4 dependent process, or escape into the cytoplasm Incorporating Pilin; MBP: Mannose-Binding Pocket; LIBS: Ligand- [9]. -
Magnetotactic Bacteria and Their Application in Medicine
Chem cal ist si ry y & h P B f i o o Dasdag and Bektas. J Phys Chem Biophys 2014, 4:2 p l h a Journal of Physical Chemistry & y n s r DOI: 10.4172/2161-0398.1000141 i u c o s J ISSN: 2161-0398 Biophysics ResearchReview Article Article OpenOpen Access Access Magnetotactic Bacteria and their Application in Medicine Suleyman Dasdag1* and Hava Bektas2 1Department of Biophysics, Medical School of Dicle University, Diyarbakir, Turkey 2Department of Biophysics, Medical School of Yuzuncu Yil University, Van / Turkey Abstract It is a known fact how the magnetic field of the Earth is very important for life. Relation between living systems and the earth magnetic field has been investigated for many years. Birds and their migration routes are the first one of the things that comes to mind when we state living things. The Earth’s magnetic field is still accepted to be the main factor for birds and other flying living beings to complete their travels correctly. The changes in migration routes, which are observed from time to time, are sometimes said to be due to the changes in the magnetic field. However, no light has been shed to this matter yet. The Earth’s magnetic field has not been sufficiently studied, and its role on small living models such as bacteria has not been adequately discussed. One of the best examples in this field is relation between the Earth’s magnetic field and “magnetotactic bacteria (MTB)”, which were discovered by Salvatore Bellini in 1963. Currently, it is claimed that magnetotactic bacteria have a widespread use in microbiology, mineralogy, limnology, physics, biophysics, chemistry, biochemistry, geology, crystallography, and astrobiology. -
Life with Compass: Diversity and Biogeography of Magnetotactic Bacteria
bs_bs_banner Environmental Microbiology (2014) 16(9), 2646–2658 doi:10.1111/1462-2920.12313 Minireview Life with compass: diversity and biogeography of magnetotactic bacteria Wei Lin,1,2 Dennis A. Bazylinski,3 Tian Xiao,2,4 the present-day biogeography of MTB, and the ruling Long-Fei Wu2,5 and Yongxin Pan1,2* parameters of their spatial distribution, will eventu- 1Biogeomagnetism Group, Paleomagnetism and ally help us predict MTB community shifts with envi- Geochronology Laboratory, Key Laboratory of the ronmental changes and assess their roles in global Earth’s Deep Interior, Institute of Geology and iron cycling. Geophysics, Chinese Academy of Sciences, Beijing 100029, China. 2France-China Bio-Mineralization and Nano-Structures Introduction Laboratory, Chinese Academy of Sciences, Beijing Iron is the fourth most common element in the Earth’s 100029, China. crust and a crucial nutrient for almost all known organ- 3 School of Life Sciences, University of Nevada at Las isms. The cycling of iron is one of the key processes in the Vegas, Las Vegas, NV, USA. Earth’s biogeochemical cycles. A number of organisms 4 Key Laboratory of Marine Ecology & Environmental synthesize iron minerals and play essential roles in global Sciences, Institute of Oceanology, Chinese Academy of iron cycling (Westbroek and de Jong, 1983; Winklhofer, Sciences, Qingdao, China. 2010). One of the most interesting examples of these 5 Laboratoire de Chimie Bactérienne, Aix-Marseille types of organisms are the magnetotactic bacteria (MTB), Université, CNRS, Marseille Cedex, France. a polyphyletic group of prokaryotes that are ubiquitous in aquatic and sedimentary environments (Bazylinski Summary and Frankel, 2004; Bazylinski et al., 2013). -
Microbiology of Endodontic Infections
Scient Open Journal of Dental and Oral Health Access Exploring the World of Science ISSN: 2369-4475 Short Communication Microbiology of Endodontic Infections This article was published in the following Scient Open Access Journal: Journal of Dental and Oral Health Received August 30, 2016; Accepted September 05, 2016; Published September 12, 2016 Harpreet Singh* Abstract Department of Conservative Dentistry & Endodontics, Gian Sagar Dental College, Patiala, Punjab, India Root canal system acts as a ‘privileged sanctuary’ for the growth and survival of endodontic microbiota. This is attributed to the special environment which the microbes get inside the root canals and several other associated factors. Although a variety of microbes have been isolated from the root canal system, bacteria are the most common ones found to be associated with Endodontic infections. This article gives an in-depth view of the microbiology involved in endodontic infections during its different stages. Keywords: Bacteria, Endodontic, Infection, Microbiology Introduction Microorganisms play an unequivocal role in infecting root canal system. Endodontic infections are different from the other oral infections in the fact that they occur in an environment which is closed to begin with since the root canal system is an enclosed one, surrounded by hard tissues all around [1,2]. Most of the diseases of dental pulp and periradicular tissues are associated with microorganisms [3]. Endodontic infections occur and progress when the root canal system gets exposed to the oral environment by one reason or the other and simultaneously when there is fall in the body’s immune when the ingress is from a carious lesion or a traumatic injury to the coronal tooth structure.response [4].However, To begin the with, issue the if notmicrobes taken arecare confined of, ultimately to the leadsintra-radicular to the egress region of pathogensIn total, and bacteria their by-productsdetected from from the the oral apical cavity foramen fall into to 13 the separate periradicular phyla, tissues. -
The Fine Structure of Diplococcus Pneumoniae
THE FINE STRUCTURE OF DIPLOCOCCUS PNEUMONIAE ALEXANDER TOMASZ, Ph.D., JAMES D. JAMIESON, M.D., and ELENA OTTOLENGtII, M.D. From The Rockefeller Institute and the New York University School of Medicine, New York ABSTRACT The fine structure of an unencapsulated strain of Diplococcus pneumoniae is described. A strik- ing feature of thcsc bacteria is an intracytoplasmic membrane system which appears to be an extension of septa of dividing bactcria. The possible function of these structures and their relationship to the plasma membrane and other types of intracytoplasmic membranes found in pncumococcus is discussed. INTRODUCTION Our main interest in the fine structure of Diplo- walls. Throughout this paper, such preparations will coccus pneumoniae stems from the fact that these be referred to as "spheroplasts." bacteria readily undergo genetic transformation. The bacteria were fixed and stained according to the method of Ryter and Kellenberger (4), embedded Prior to undertaking electron microscope studies in cross-linked methacrylate, and sectioned with a on this process, the fine structure of pneumococcal Porter-Blum mlcrotome using a diamond knife. The cells in thin sections was examined. During the sections were stained with lead according to the preliminary stage of these studies on a transform- method of Karnovsky (5) (method B) and were able strain, we observed some unique membranous examined in the RCA electron microscopes models structures which, to the best of our knowledge, 2B, 3F, or in the Siemens Elmiskop I. have not previously been described in bacteria. RESULTS MATERIALS AND METHODS The nuclear region of pneumococcus resembles that Unencapsulated strains of Diplocoecus pneumoniae R6, of other bacteria prepared by the method of R1, and some nutritional mutants derived from R6 Ryter and Kellenberger (4). -
Identification of Type 3 Fimbriae in Uropathogenic Escherichia Coli
JOURNAL OF BACTERIOLOGY, Feb. 2008, p. 1054–1063 Vol. 190, No. 3 0021-9193/08/$08.00ϩ0 doi:10.1128/JB.01523-07 Copyright © 2008, American Society for Microbiology. All Rights Reserved. Identification of Type 3 Fimbriae in Uropathogenic Escherichia coli Reveals a Role in Biofilm Formationᰔ Cheryl-Lynn Y. Ong,1 Glen C. Ulett,1 Amanda N. Mabbett,1 Scott A. Beatson,1 Richard I. Webb,2 Wayne Monaghan,3 Graeme R. Nimmo,3 David F. Looke,4 1 1 Alastair G. McEwan, and Mark A. Schembri * Downloaded from School of Molecular and Microbial Sciences1 and Centre for Microscopy and Microanalysis,2 University of Queensland, Brisbane, Australia, and Queensland Health Pathology Service3 and Infection Management Services, Princess Alexandra Hospital, Brisbane, Australia4 Received 21 September 2007/Accepted 17 November 2007 Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection in the United States. Uropathogenic Escherichia coli (UPEC), the most common cause of CAUTI, can form biofilms on indwelling catheters. Here, we identify and characterize novel factors that affect biofilm formation by UPEC http://jb.asm.org/ strains that cause CAUTI. Sixty-five CAUTI UPEC isolates were characterized for phenotypic markers of urovirulence, including agglutination and biofilm formation. One isolate, E. coli MS2027, was uniquely proficient at biofilm growth despite the absence of adhesins known to promote this phenotype. Mini-Tn5 mutagenesis of E. coli MS2027 identified several mutants with altered biofilm growth. Mutants containing insertions in genes involved in O antigen synthesis (rmlC and manB) and capsule synthesis (kpsM) possessed enhanced biofilm phenotypes. Three independent mutants deficient in biofilm growth contained an insertion in a gene locus homologous to the type 3 chaperone-usher class fimbrial genes of Klebsiella pneumoniae. -
Laboratory Exercises in Microbiology: Discovering the Unseen World Through Hands-On Investigation
City University of New York (CUNY) CUNY Academic Works Open Educational Resources Queensborough Community College 2016 Laboratory Exercises in Microbiology: Discovering the Unseen World Through Hands-On Investigation Joan Petersen CUNY Queensborough Community College Susan McLaughlin CUNY Queensborough Community College How does access to this work benefit ou?y Let us know! More information about this work at: https://academicworks.cuny.edu/qb_oers/16 Discover additional works at: https://academicworks.cuny.edu This work is made publicly available by the City University of New York (CUNY). Contact: [email protected] Laboratory Exercises in Microbiology: Discovering the Unseen World through Hands-On Investigation By Dr. Susan McLaughlin & Dr. Joan Petersen Queensborough Community College Laboratory Exercises in Microbiology: Discovering the Unseen World through Hands-On Investigation Table of Contents Preface………………………………………………………………………………………i Acknowledgments…………………………………………………………………………..ii Microbiology Lab Safety Instructions…………………………………………………...... iii Lab 1. Introduction to Microscopy and Diversity of Cell Types……………………......... 1 Lab 2. Introduction to Aseptic Techniques and Growth Media………………………...... 19 Lab 3. Preparation of Bacterial Smears and Introduction to Staining…………………...... 37 Lab 4. Acid fast and Endospore Staining……………………………………………......... 49 Lab 5. Metabolic Activities of Bacteria…………………………………………….…....... 59 Lab 6. Dichotomous Keys……………………………………………………………......... 77 Lab 7. The Effect of Physical Factors on Microbial Growth……………………………... 85 Lab 8. Chemical Control of Microbial Growth—Disinfectants and Antibiotics…………. 99 Lab 9. The Microbiology of Milk and Food………………………………………………. 111 Lab 10. The Eukaryotes………………………………………………………………........ 123 Lab 11. Clinical Microbiology I; Anaerobic pathogens; Vectors of Infectious Disease….. 141 Lab 12. Clinical Microbiology II—Immunology and the Biolog System………………… 153 Lab 13. Putting it all Together: Case Studies in Microbiology…………………………… 163 Appendix I.