Bacteria

Definition

Bacteria are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in mutualistic, commensal and parasitic relationships with plants and animals. Most bacteria have not been characterised and there are many species that cannot be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology.

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Life Caulobacteria Cavalier-Smith Cell (biology)Cell division Cell envelope Cell growth Cell membrane Cell metabolism Cell nucleus Cell signal Cell signaling Cell theory Cell wall Cellulose Cercozoa Cerebrospinal fluid Chaetognatha Charophyta Cheese Chemical industry Chemotaxis Chemotrophy Chitin Chitinivibrionia Chlamydia (bacterium)Chlamydiia Chlamydiota Chloramphenicol Chlorobiia Chloroflexia Chloroflexota Chlorophyta Chloroplast Chlorosome Cholera Chordate Christian Gottfried Ehrenberg Chromosome Chrompodellid Chrysiogenota Chytridiomycota Ciliate Circular bacterial chromosome Clavaviridae Clinical pathology Cloacimonadota Clonal colony Clonally transmissible cancer Clone (genetics)Cloning vector Clostridia Clostridioides difficile infection Clostridium Clostridium botulinum Clostridium tetani Cnidaria Cobalamin Coccobacillus Coccus Cofactor (biochemistry)Cold seep Comets Commensal Commensalism Competitive exclusion Conifer Copper Coprothermobacteria Coprothermobacterota Coral microbiome Coriobacteriia Coronary heart disease Cosmid Cosmopoliota Cryosericota Cryptista Cryptoendoliths Ctenophora Cyanobacteria Cyanobacterial Cyanophyceae Cyanotheca Cycad Cycliophora Cystic fibrosis Cytoplasm Cytosine Cytoskeleton DNA DNA repair DNA replication DNA sequencing Dadaibacteriota Daniel Mazia Dark-field microscopy Dead Sea Decomposition Deep biosphere Defective interfering particle Deferribacteraceae Deferribacterota Deferrimicrobiota Deferrisomatia Deferrisomatota Dehalococcoidia Deinococci Deinococcota Deinococcus radiodurans Delongiibacteriota Denitrification Desantisiibacteriota Desiccation Desulfobacteria Desulfobulbia Desulfomonilia Desulfotomaculota Desulfovibrio vulgaris Desulfovibrionia Detergent Detritivore Diaminopimelic acid Diaphoretickes Diarrhea Diazotroph Dictyoglomota Dictyoglomus Dicyemida Dietary supplement Diffusion Diffusion barrier Digestive enzyme Dimension Dimethylmercury Diminutive Dinodnavirus Dinoflagellate Diphtheria Directed panspermia Disease Disinfectant Dissulfuribacteria Diversity-generating retroelement Division of labour Domain (biology)Dormiibacterota Duplodnaviria Dysbiosis EPPO Code Earliest known life forms Earth's atmosphere Earth's crust Echinoderm Ecological stability Ecology Edwardsiibacteriota Effluvivivacota Efunaviria Eiseniibacteriota Electrochemical gradient Electrochemical potential Electron Electron donor Electron micrograph Electron microscope Electron microscopy Electron transport chain Electryoneota Elulimicrobiota Elusimicrobiota Embryophyte Enantiomer Encyclopedia of Life Endogenous viral element Endomyxa Endospore Endosymbiont Endotoxin Energy (biology)Enterobacteriaceae Entoprocta Environmentally friendly Enzyme Enzyme inhibitor Enzyme kinetics Eoleptonema Episome Epulopiscium fishelsoni Ernst Haeckel Escherichia coli Essential gene Ethanol Etymonline Euglenozoa Eukaryote Eurekaviridae Evolution Evolution of bacteria Evolutionary history of life Exotoxin Exponential growth Extracellular polymeric substance Extraterrestrial life Extremophile Exxon Valdez oil spill FCB superphylum Facultative aerobe Facultative anaerobe Facultative anaerobic organism Fatty acid Fatty acid metabolism Fecal microbiota transplant Feces Ferdinand Cohn Fermentation (biochemistry)Fermentation (food)Fermentibacterota Ferrimonilis Fervidibacterota Fibrobacterota Fidelibacter Filamentous bacteria Fimbria (bacteriology)Fire blight Firestoneibacteriota Flagella Flagellum Flatworm Floreoviria Folic acid Food microbiology Foodborne illness Fornicata Fosmid Fossil Francevillian biota Fungal prion Fungus Fuselloviridae Fusobacteriota GC-content Gamma ray Gas vesicle Gastrotricha Gemmatimonadota Gene Gene expression General bacterial porin family Genetic material Genetic recombination Genetically modified bacteria Genetics Genome Genome Taxonomy Database Genus Geoarchaeota Geothermal springs Germ theory of disease Geyser Ginkgophyta Glaucophyte Gliding motility Global Biodiversity Information Facility 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Hydrogenosome Hydrothermal vent Hydrothermal vent microbial communities Hydrothermarchaeota Hydrothermota Hygrocrocis Hypha Hyphochytriomycetes INaturalist Iainarchaeota Ignavibacteria Ignaz Semmelweis Immune system Immunology Immunosuppression Impedance microbiology Implant (medicine)Inactivating mutation Incertae sedis Infection Infectious disease Inflammation Innate immunity Insecticide Insulin Integrated Taxonomic Information System Integrative and conjugative element Intensive farming International Census of Marine Microbes International Code of Nomenclature of Bacteria International Code of Nomenclature of Prokaryotes International Committee on Systematic Bacteriology Intestine Intron Ion Isaac Asimov Isolation (microbiology)Itzamnaviridae Jeewanu Johne's disease Joseph Lister Kapaibacteriota Kill the Winner hypothesis Kinorhyncha Kiritimatiellota Koch's postulates Koukoulia Krumholzibacteriota Kryptoniota LUCA Lactic acid Lactic acid bacteria Lactobacillus Lactococcus Last universal common ancestor Lateral gene transfer Latescibacterota Latin Leaf spot Lentisphaerae Lentisphaerota Lepidoptera Leprosy Leptospirillaeota Lernaellota Life Lindowiibacteriota Lines on the Antiquity of Microbes Lipid bilayer Lipophilic bacteria Lipopolysaccharide Lipoprotein Lipoteichoic acid List of Prokaryotic names with Standing in Nomenclature Listeria Lithacetigenota Lithotroph Liverwort Lomiviridae Loricifera Louis Pasteur Lung microbiota Lycophyte Lysogenic cycle Lytic cycle Macinerneyibacteriota Macromolecule Macrophage Magnetococcales Magnetotaxis Magnoovum Malawimonada Margulisiibacteriota Mariana Trench Marine microbial symbiosis Marine microorganisms Marine prokaryotes Marine protists Marine viruses Marinisomatota Marlene Belfort Mastitis in dairy cattle Mathematical model Matrix-assisted laser desorption/ionization Medical device Medical microbiology Medicine Meiosis Mendosicutes Meningitis Mercury (element)Metabolic pathway Metabolism Meteoroid Methane 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Moduliflexota Mold (fungus)Molecular biology Molecular systematics Mollicutes Mollusca Monera Morphology (biology)Moss Most recent common ancestor Motility Mucous membrane Muiribacteriota Mutagen Mutation Mutualism (biology)MycoBank Mycobacteria Mycobacterium Mycobacterium avium complex Mycobacterium leprae Mycobacterium tuberculosis Mycolic acid Mycology Mycoplasma Mycoplasma laboratorium Mycoplasmatota Myelinogenesis Myxobacteria Myxococcia Myxococcota Myxococcus xanthus N-Acetylglucosamine N-Acetylmuramic acid NASA Naldaviricetes Nanaerobe Nanobacterium Nanobdellota Nanobe Nanohalarchaeota National Center for Biotechnology Information Natranaerobiales Natural competence Nature Geoscience Nebulidia Negative staining Negativicutes Neisseria Neisseria gonorrhoeae Nematode Nematomorpha Nemertea Neo-Latin Neocallimastigomycota Nervous system Nezhaarchaeota Nibbleridia Nipumfusiviridae Nitrate Nitriliruptoria Nitrogen fixation Nitrogenase Nitroplast Nitrosediminicolota Nitrospinota 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