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Bacteria: One of the three domains of life (the others being Eukarya and Archaea), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to Oxygen: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or Phototrophy (via light reaction); for chemotrophs by their source of chemical energy: Chemolithotrophy (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for Carbon; Nitrogen; etc.; Heterotrophy (from organic sources) or Autotrophy (from Carbon dioxide). They can also be classified by whether or not they stain (based on the structure of their Cell walls) with Crystal violet dye: gram-negative or gram-positive.

Culturing and Enumerating Bacteria from Soil Samples

JoVE 10099

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Authors: Bradley Schmitz and Luisa Ikner

Surface soils are a heterogeneous mixture of inorganic and organic particles that combine together to form secondary aggregates. Within and between the aggregates are voids or pores that visually contain both air and water. These conditions create an ideal ecosystem for bacteria, so all soils contain vast populations of bacteria, usually over 1 million per gram of soil. Bacteria are the simplest of microorganisms, known as prokaryotes. Within this prokaryotic group, there are the filamentous microbes known as actinomycetes. Actinomycetes are actually bacteria, but they are frequently considered to be a unique group within the classification of bacteria because of their filamentous structure, which consists of multiple cells strung together to form hyphae. This experiment uses glycerol case media that select for actinomycete colonies, during dilution and plating. Typically, actinomycetes are approximately 10% of the total bacterial population. Bacteria and actinomycetes are found in every environment on Earth, but the abundance and diversity of these microbes in soil is unparalleled. These microbes are also essential for human life and affect what people eat


 Environmental Microbiology

Measuring Growth and Gene Expression Dynamics of Tumor-Targeted S. Typhimurium Bacteria

1Health Sciences and Technology, Massachusetts Institute of Technology, 2Department of Bioengineering, University of California, San Diego, 3Biocircuits Institute, University of California, San Diego, 4Molecular Biology Section, Division of Biological Science, University of California, San Diego, 5Broad Institute of Harvard and MIT, 6Department of Medicine, Brigham and Women's Hospital, 7Electrical Engineering and Computer Science and David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 8Howard Hughes Medical Institute

JoVE 50540


 Immunology and Infection

Fluorescence in situ Hybridizations (FISH) for the Localization of Viruses and Endosymbiotic Bacteria in Plant and Insect Tissues

1Department of Entomology, Volcani Center, 2Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, 3Department of Applied Sciences, Institute for Adriatic Crops and Karst Reclamation, 4The Institute of Plant Sciences, Volcani Center

JoVE 51030


 Immunology and Infection

Rapid Identification of Gram Negative Bacteria from Blood Culture Broth Using MALDI-TOF Mass Spectrometry

1Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital, 2Centre for Research Excellence in Critical Infection, Westmead Millennium Institute, Westmead Hospital, 3Sydney Emerging Infectious Diseases Institute, University of Sydney, Westmead Hospital

JoVE 51663


 Immunology and Infection

Isolation of Fecal Bacteria from Water Samples by Filtration

JoVE 10213

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Luisa Ikner

The quality of water destined for use in agricultural, recreational, and domestic settings is of great importance due to the potential for outbreaks of waterborne disease. Microbial agents implicated in such events include parasites, bacteria, and viruses that are shed in high numbers in the feces of infected people and animals. Transmission to new and susceptible hosts may then occur via the fecal-oral route upon ingestion of contaminated water. Therefore, the ability to monitor water sources for the presence of pathogenic microorganisms is significant in order to ensure public health. Due to the sheer number and variety of potential fecal-oral pathogens that may be present in water and their variable concentrations, it is impractical and expensive to assay directly for each one of them on a regular basis. Therefore, the microbiological assays for water quality monitoring employ coliform indicator bacteria. Coliforms comprise, in part, the normal intestinal microflora of warm-blooded mammals, are non-pathogenic, and are consistently excreted in the feces. Therefore, the detection of coliform bacteria in water means that a fecal release occurred, and that harmful pathogenic m


 Environmental Microbiology

Engineering Adherent Bacteria by Creating a Single Synthetic Curli Operon

1UMR CNRS 5557 Ecologie Microbienne, Université Lyon 1, Université de Lyon, 2Département Biosciences, INSA de Lyon, Université de Lyon, 3INSERM U758, Ecole Normale Supérieure de Lyon, Université de Lyon, 4Laboratoire de Génie Civil et Ingénierie Environnementale, INSA de Lyon, Université de Lyon

JoVE 4176


 Bioengineering

Analyzing Cellular Internalization of Nanoparticles and Bacteria by Multi-spectral Imaging Flow Cytometry

1Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, 2Amnis Corporation, 3Department of Chemical and Biological Engineering, Iowa State University

JoVE 3884


 Bioengineering

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

1Institute for Environmental Protection and Research (ISPRA), Rome (Italy), 2Department of Biology, Tor Vergata University, Rome (Italy), 3Department of Biology and Evolution of Marine Organisms, Stazione Zoologica, Anton Dohrn, Naples (Italy)

JoVE 55211


 Environment

Gram Staining of Bacteria from Environmental Sources

JoVE 10092

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Luisa Ikner

The spectrum of research in environmental microbiology is broad in scope and application potential. Whether the work is bench-scale with known bacterial isolates, or in the field collecting soil or water samples containing unknown bacterial isolates, the ability to quickly and visually discern culturable populations of interest remains of great import to environmental microbiologists even today with the abundance of molecular techniques available for use. This video will demonstrate one such technique, known as Gram staining.


 Environmental Microbiology

Essential Metal Uptake in Gram-Negative Bacteria: X-Ray Fluorescence, Radioisotopes, and Cell Fractionation

1Graduate Biomedical Sciences Microbiology Theme, University of Alabama at Birmingham, 2Department of Radiology, University of Alabama at Birmingham, 3Office of the Provost, University of Alabama at Birmingham, 4Department of Pharmacology and Toxicology, University of Alabama at Birmingham

Video Coming Soon

JoVE 57169


 JoVE In-Press

Microscopy-based Assays for High-throughput Screening of Host Factors Involved in Brucella Infection of Hela Cells

1Focal Area Infection Biology, Biozentrum, University of Basel, 2Centre d’Immunologie de Marseille-Luminy, Université de la Méditérannée UM2, INSERM U1104 CNRS UM7280, 3Departmento de Microbiologìa and Instituto de Salud Tropical, Universidad de Navarra, 4BioDataAnalysis GmbH

JoVE 54263


 Immunology and Infection

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