Click here to Download (DepositeFiles Link) Note: Use Regular Download in Depositefiles
Books Description
Cyanobacteria, also known as blue-green algae, blue-green bacteria or cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. They are a significant component of the marine nitrogen cycle and an important primary producer in many areas of the ocean, but are also found in habitats other than the marine environment; in particular, cyanobacteria are known to occur in both freshwater and hypersaline inland lakes. They are found in almost every conceivable environment, from oceans to fresh water to bare rock to soil.
Cyanobacteria are the only group of organisms that are able to reduce nitrogen and carbon in aerobic conditions, a fact that may be responsible for their evolutionary and ecological success. Certain cyanobacteria also produce cyanotoxins. This new book presents a broad variety of international research on this important organism.
Handbook on Cyanobacteria: Biochemistry, Biotechnology and Applications
Bacteria in Biology, Biotechnology and Medicine is a broadly based textbook of pure and applied bacteriology. Written in clear language, the up-to-date text gives readers access to new ideas and developments in the current literature. The book is intended primarily for undergraduates and postgraduates in biology, biotechnology, medicine, veterinary science, pharmacology, microbiology, food science, environmental science and agriculture; no prior knowledge of bacteria is assumed.
The sixth edition has been extensively updated; much of the text is new, or re-written, and there are many new references. Over 70 genera of bacteria, listed alphabetically, are described in the Appendix. Cross-references and a detailed index, maximise… Reviews of previous editions:
“….a useful survey of the subject for students contemplating specialization.” —Nature
“Singleton assumes the reader has no prior knowledge of DNA and gene expression, and does an extraordinary job of explaining things from scratch.” —Quarterly Review of Biology
“….recommended to undergraduates and those seeking clear explanations of basic concepts of bacteriology.” —Journal of Medical Microbiology
Bacteria in Biology, Biotechnology and Medicine By Paul Singleton
Bacteria in Biology, Biotechnology and Medicine is a broadly based textbook of pure and applied bacteriology. Written in clear language, the up-to-date text gives readers access to new ideas and developments in the current literature. The book is intended primarily for undergraduates and postgraduates in biology, biotechnology, medicine, veterinary science, pharmacology, microbiology, food science, environmental science and agriculture; no prior knowledge of bacteria is assumed.
The sixth edition has been extensively updated; much of the text is new, or re-written, and there are many new references. Over 70 genera of bacteria, listed alphabetically, are described in the Appendix. Cross-references and a detailed index, maximise… Reviews of previous editions:
“….a useful survey of the subject for students contemplating specialization.” —Nature
“Singleton assumes the reader has no prior knowledge of DNA and gene expression, and does an extraordinary job of explaining things from scratch.” —Quarterly Review of Biology
“….recommended to undergraduates and those seeking clear explanations of basic concepts of bacteriology.” —Journal of Medical Microbiology
Bacteria in Biology, Biotechnology and Medicine By Paul Singleton
Click here to Download (DepositeFiles Link) Note: Use Regular Download in Depositefiles
Books Description
Cyanobacteria, also known as blue-green algae, blue-green bacteria or cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. They are a significant component of the marine nitrogen cycle and an important primary producer in many areas of the ocean, but are also found in habitats other than the marine environment; in particular, cyanobacteria are known to occur in both freshwater and hypersaline inland lakes. They are found in almost every conceivable environment, from oceans to fresh water to bare rock to soil.
Cyanobacteria are the only group of organisms that are able to reduce nitrogen and carbon in aerobic conditions, a fact that may be responsible for their evolutionary and ecological success. Certain cyanobacteria also produce cyanotoxins. This new book presents a broad variety of international research on this important organism.
Handbook on Cyanobacteria: Biochemistry, Biotechnology and Applications
Communicable diseases are the most common cause of death in developing countries, and their diagnosis and treatment represent a significant challenge to the health services in those areas. The World Health Organization has long
been actively involved in developing and promoting standard techniques for laboratory investigations of such diseases, a first attempt to standardize susceptibility testing of bacterial pathogens being made in 1960. Following on from this, in 1976, the WHO Expert Committee on Biological Standardization drew up requirements for antibiotic susceptibility testing using the disc method.
At the same time, efforts were being made to introduce quality control into laboratory performance. In 1981, WHO established an International External Quality Assessment Scheme for Microbiology. The laboratories that are involved in this scheme are able to play a leading role in the implementation of national quality assessment schemes at all levels of the health care system.
The present publication brings together and updates the various guidelines produced by WHO over the years on sampling of specimens for laboratory investigation, identification of bacteria, and testing of antimicrobial resistance. The information included is intended to lead to harmonization of microbiological investigations and susceptibility testing, and to improve the quality of laboratories at both central and intermediate levels. It concentrates on the procedures to be followed, rather than the basic techniques of microscopy and staining, which have been described in detail in another WHO publication
Basic Laboratory Procedures in Clinical Bacteriology
Genetic investigations and manipulations of bacteria and bacteriophage have made vital contributions to our basic understanding of living cells and to the development of molecular biology and biotechnology. This volume is a survey of the genetics of bacteria and their viruses, and it provides students with a comprehensive introduction to this rapidly changing subject. The book is written for upper level undergraduates and beginning graduate students, particularly those who have had an introductory genetics course.
The fifth edition has been extensively revised to reflect recent advances in the field. The book now has a reader-friendly look, with end-of-chapter questions, “Thinking Ahead” and “Applications” boxes to challenge students’ comprehension and insights. A complete glossary of commonly used terms has been revised and expanded.
Table of Contents:
Fundamentals of Bacterial and Viral Genetics
Replication and Analysis of DNA
Mutations and Mutagenesis
Transcription and Translation: Processes and Basic Regulation
DNA Repair and Simple Recombination
T4 Bacteriophage as a Model Genetic System
Genetics of Other Intemperate Bacteriophages
Genetics of Temperate Bacteriophages
Transduction
Genetic Transformation
Conjugation and the Escherichia coli Paradigm
Plasmids and Conjugation Systems Other than F
Plasmid Molecular Biology
Advanced Regulatory Topics
Site-Specific Recombination
Applied Bacterial Genetics
Bacterial and Bacteriophage Evolution
Bacterial and Bacteriophage Genetics By Edward A. Birge
Since its first publication in 1929, Topley & Wilson’s Microbiology & Microbial Infections has grown from one to eight volumes, a reflection of the ever-increasing breadth and depth of knowledge in each of the areas covered. The tenth edition continues the tradition of providing the most comprehensive available reference on microorganisms and related infectious diseases. The new edition of Topley & Wilson’s Microbiology & Microbial Infections is an essential addition to the bookshelves of medical microbiologists, immunologists, infectious disease specialists and public health professionals, as well as being a standard reference for specialists within the pharmaceutical industry, trainees across the medical sub-specialities, and laboratory technicians.
The 10th edition features:
the latest information on epidemiology, identification, classification, and new and emerging infections, all supported by the basic science that underlies infectious disease
each volume includes the best writing in the fields of Bacteriology, Virology, Medical Mycology, Parasitology, and Immunology
a new Immunology volume – both a complement to the other titles, and an excellent reference work for every immunologist
fully integrated colour for the first time – the text is supported by over 1,400 photographs and 700 line drawings
an international, acclaimed editorial team and a highly respected group of over 400 contributors, drawing on best practice from over 20 countries
a comprehensive cumulative index
The 10th edition of Topley & Wilson’s Microbiology & Microbial Infections is an essential addition to the bookshelves of medical microbiologists, immunologists, infectious disease specialists, pathologists, travel and tropical medicine specialists, and public health scientists; and will also be a standard reference for all those working in the pharmaceutical industry, trainees across the medical subspecialties, and laboratory technicians. The breadth of information available in the tenth edition is astonishing, and will support academic and clinical practice for many years to come.
Topley and Wilson’s Microbiology and Microbial Infections, 8 Volume Set, 10th Edition
Gram staining, also called Gram's method, is a method of differentiating bacterial species into two large groups (gram-positive and gram-negative). The name comes from its inventor, Hans Christian Gram.
Gram staining differentiates bacteria by the chemical and physical properties of their cell walls by detecting peptidoglycan, which is present in a thick layer in gram-positive bacteria. In a Gram stain test, gram-positive bacteria retain the crystal violet dye, while a counterstain (commonly safranin or fuchsine) added after the crystal violet gives all gram-negative bacteria a red or pink coloring.
The Gram stain is almost always the first step in the identification of a bacterial organism. While Gram staining is a valuable diagnostic tool in both clinical and research settings, not all bacteria can be definitively classified by this technique. This gives rise to gram-variable and gram-indeterminate groups as well.
Uses
Gram staining is a bacteriological laboratory technique used to differentiate bacterial species into two large groups (gram-positive and gram-negative) based on the physical properties of their cell walls.[5] Gram staining is not used to classify archaea, formerly archaeabacteria, since these microorganisms yield widely varying responses that do not follow their phylogenetic groups.
The Gram stain is not an infallible tool for diagnosis, identification, or phylogeny, and it is of extremely limited use in environmental microbiology. It still competes with molecular techniques even in the medical microbiology lab. Some organisms are gram-variable (that means, they may stain either negative or positive); some organisms are not susceptible to either stain used by the Gram technique. In a modern environmental or molecular microbiology lab, most identification is done using genetic sequences and other molecular techniques, which are far more specific and informative than differential staining.
Gram staining has proven as effective a diagnostic tool as PCR, particularly with regards to gonorrhoea diagnosis in Kuwait. The similarity of the results of both Gram stain and PCR for diagnosis of gonorrhea was 99.4% in Kuwait.
Medical[edit]
See also: Gram-negative bacterial infection and Gram-positive bacterial infection
Gram stains are performed on body fluid or biopsy when infection is suspected. Gram stains yield results much more quickly than culturing, and is especially important when infection would make an important difference in the patient's treatment and prognosis; examples are cerebrospinal fluid for meningitis and synovial fluid for septic arthritis.
Staining mechanism[edit]
Gram-positive bacteria have a thick mesh-like cell wall made of peptidoglycan (50–90% of cell envelope), and as a result are stained purple by crystal violet, whereas gram-negative bacteria have a thinner layer (10% of cell envelope), so do not retain the purple stain and are counter-stained pink by the Safranin. There are four basic steps of the Gram stain:
Applying a primary stain (crystal violet) to a heat-fixed smear of a bacterial culture. Heat fixation kills some bacteria but is mostly used to affix the bacteria to the slide so that they don't rinse out during the staining procedure.
The addition of iodide, which binds to crystal violet and traps it in the cell,
Rapid decolorization with ethanol or acetone, and
Counterstaining with safranin.[9] Carbol fuchsin is sometimes substituted for safranin since it more intensely stains anaerobic bacteria, but it is less commonly used as a counterstain.
Crystal violet (CV) dissociates in aqueous solutions into CV+
and chloride (Cl−
) ions. These ions penetrate through the cell wall and cell membrane of both gram-positive and gram-negative cells. The CV+
ion interacts with negatively charged components of bacterial cells and stains the cells purple.
Iodide (I−
or I−
3) interacts with CV+
and forms large complexes of crystal violet and iodine (CV–I) within the inner and outer layers of the cell. Iodine is often referred to as a mordant, but is a trapping agent that prevents the removal of the CV–I complex and, therefore, color the cell.
When a decolorizer such as alcohol or acetone is added, it interacts with the lipids of the cell membrane. A gram-negative cell loses its outer lipopolysaccharide membrane, and the inner peptidoglycan layer is left exposed. The CV–I complexes are washed from the gram-negative cell along with the outer membrane. In contrast, a gram-positive cell becomes dehydrated from an ethanol treatment. The large CV–I complexes become trapped within the gram-positive cell due to the multilayered nature of its peptidoglycan. The decolorization step is critical and must be timed correctly; the crystal violet stain is removed from both gram-positive and negative cells if the decolorizing agent is left on too long (a matter of seconds).
After decolorization, the gram-positive cell remains purple and the gram-negative cell loses its purple color. Counterstain, which is usually positively charged safranin or basic fuchsine, is applied last to give decolorized gram-negative bacteria a pink or red color.
Some bacteria, after staining with the Gram stain, yield a gram-variable pattern: a mix of pink and purple cells are seen. The genera Actinomyces, Arthobacter, Corynebacterium, Mycobacterium, and Propionibacterium have cell walls particularly sensitive to breakage during cell division, resulting in gram-negative staining of these gram-positive cells. In cultures of bacillus, Butyrivibrio, and Clostridium, a decrease in peptidoglycan thickness during growth coincides with an increase in the number of cells that stain gram-negative. In addition, in all bacteria stained using the Gram stain, the age of the culture may influence the results of the stain.
Locomotion or motility is important characteristic of bacteria. Bacterial locomotion is of three types: Flagellar, Spirochaetal and Gliding movement. The word motility, movement and locomotion are used synonymously.
Flagellar motility:
This type of motility is caused by flagella, cell surface appendages. Flagellum has typical structure; it is embedded in cell wall by S ring or stator (hook) and basal body or motor. M ring is attached to the flagellum and acts like a rotor (shaft). P and L are also present and work like bearings or bushers. Basal body is powered by proton energy, which is movement of ions between M and S rings. Transformation of proton energy into work operates flagella in clockwise and counterclockwise directions. Depending upon location of flagella, bacteria can swim smoothly, reverse the movement backward or forward or tumble. Peritrichously flagellated bacteria bear flagella all over the surface move by tumbling or anticlockwise swimming. Polar flagella (mono, bi or multipolar) are present at the ends of cell and bacteria move in one direction and as well as in reversal. Flagellar motility is present in Pseudomonas, Vibrio, Spirillum, Azospirillum, Klebsiella, Salmonella, Proteus and etc.
Spirochaetal movement:
Spirochaetal movement is seen in all genera of bacterial group (V), 'The Spirochetes' of Bergey's Manual of Determinative Bacteriology. Important genera include, Spirochaeta, Cristispira, Treponema, Borrelia and Leptospira. Spirochetes are helical bacteria. They have flagella like axial filament buried in space between inner and outer membranes of cell wall. Axial filament is composed of 2 or more fibrils which are embedded in inner membrane and acts like basal body or motor. Spirochetes can perform flexing, swimming, creeping or spinning types of movements. Imagination of motion of flexible helical rod in air will give you an exact idea about spirochetal movement.
Gliding movement:
Like spirochetes, gliding motility is represented by special bacteria, 'The Gliding Bacteria' group (II) of Bergey's Manual of Determinative Bacteriology. Bacteria move by gliding on the surface! They do not have flagellar structures either internally or externally but they secrete slimy substance like snails during locomotion. The exact mechanism of gliding locomotion is still unknown but some scientists have suggested presence of fimbriae like appendages at the poles of glider cell. The generation of contractile waves or surface tension or pushing by secreted slime was also proposed as possible mechanisms of gliding. Principle glider genera are Myxococcus, Archangium, Cystobacter, Melittangium, Stigmatella, Polyangium, Nannocystis, Chondromyces, Cytophaga, Flexithrix, Herpetosiphon, Beggiatoa, Saprospira, Thioplaca, Leucothrix, Alysiella, Achroonema and cyanobacterium Oscillatoria.
Laboratory detection and assay:
Motility can be directly observed under light microscope by hanging drop in cavity slide or wet mount preparation. It is important to determine true and false motility microscopically. Truly motile bacteria will show propelling action towards definite direction, as if they are pushing themselves with efforts! Nonmotile bacteria also appear to be motile because of bombardment of liquid medium particles or air currents. Motility of nonmotile bacteria is zigzag and directionless. This movement of nonmotile bacteria is actually a Brownian movement; even dead bacteria seem to be moving because of this movement. Craigie's tube or capillary tube can be used by placing them in broth culture for observation of directed movement of bacteria towards chemical or physical gradients with time. All motile bacteria show movement towards chemical or physical gradients. This phenomenon is known as tactic response. Chemical or physical gradient can be attractant or repellent and accordingly, tactic response would be positive or negative. Presence of gradients is sensed by special receptors of bacteria. Thus swimming towards certain glucose concentration present in the medium would be positive chemotactic or chemotaxis. Similarly, motile bacteria exhibit phytotaxis (light intensity) and magnetotaxis (magnetic particles) responses. Motile bacteria are assayed on semisolid agar or broth medium for chemotaxis and are very important in species identification and classification.
Importance of bacterial locomotion:
Chemotactic behavior and survival:
Motility confers bacteria an ability to change direction. This is important when bacteria require moving away or towards repellents or attractants respectively. It avoids unfavorable conditions of habitat and offers protection. It is thus important in the survival and offers to choose favorable environment containing positive stimuli, light, gravity or chemicals for bacteria.
Root colonization:
Root colonization is perquisite for establishment of bacteria in the rhizosphere region. Motile bacteria are effective root colonizers and can swim towards root exudates or other nutrient gradients earlier than nonmotile bacteria. Pseudomonads and Azospirilla are very efficient in attachment and subsequent root colonization of their host plants.
Pathogenesis: Most human pathogenic bacteria (Campylobacter, Salmonella and Vibrio) and saprophytes or opportunists (Escherichia) are motile and motility is important for attachment and colonization of cell wall of intestine and other vital organs.
Motile versus nonmotile:
Some bacteria like Acinetobacter spp. show twitching or jumping type of motility even though flagella are absent in them. These bacteria show the twitching particularly on semisolid media and also present chemotactic response. Twitching motility is thought to be because of piliated cell surface. It is the favorite topic of interest and research that why some bacteria are nonmotile? It has been found that in some bacterial genera that nonmotile species are equally efficient like their motile species. These nonmotile bacteria also possessed flagellar appendages; but basal body or motor function was found to be impaired or paralyzed. Reason for their efficiency even in absence of motility however could not be explained.
This book briefly describes the basic molecular bacteriology including bacterial Chromosome, molecular techniques used in bacteriology, quorum sensing, Bacterial signal transduction, gene transfer among bacteria in the natural environment, mitochondrial DNA, Index and References.
ISBN1449542832
EAN‐139781449542832
Primary Category: Science / General
Publication Date: October 4 2009
Language: English
Author: Dr Mohammad Reza Shakibaie Ph.D.
Chapter 1
Bacterial chromosome
Chapter 2
Bacterial gene expression
Chapter 3
Molecular techniques in bacteriology
Chapter 4
Genetic exchange among bacteria in the environment
