Bacteria (/bækˈtɪəriə/ ; sg.: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large...

Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless...

Coliform bacteria are defined as either motile or non-motile Gram-negative non-spore forming bacilli that possess β-galactosidase to produce acids and...

Gram-negative bacteria are bacteria that unlike gram-positive bacteria do not retain the crystal violet stain used in the Gram staining method of bacterial...

gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad...

Spiral bacteria, bacteria of spiral (helical) shape, form the third major morphological category of prokaryotes along with the rod-shaped bacilli and round...

sulfur bacteria in Wiktionary, the free dictionary. Sulfur bacteria may refer to: Green sulfur bacteria Purple sulfur bacteria Sulfate-reducing bacteria Sulfur-reducing...

Putrefying/decay bacteria are bacteria involved in putrefaction of living matter. Along with other decomposers, they play a critical role in recycling...

Bioluminescent bacteria are light-producing bacteria that are predominantly present in sea water, marine sediments, the surface of decomposing fish and...

In some forms of photosynthetic bacteria, a chromatophore is a pigmented(coloured), membrane-associated vesicle used to perform photosynthesis. They contain...

Intracellular bacteria are bacteria that have the capability to enter and survive within the cells of the host organism. Many of them are capable of growth...

Nitrifying bacteria are chemolithotrophic organisms that include species of genera such as Nitrosomonas, Nitrosococcus, Nitrobacter, Nitrospina, Nitrospira...

Purple bacteria or purple photosynthetic bacteria are Gram-negative proteobacteria that are phototrophic, capable of producing their own food via photosynthesis...

up bacteria in Wiktionary, the free dictionary. Bacteria are a major group of prokaryotic living organisms. Bacteria may also refer to: Bacteria (malware)...

Atypical bacteria are bacteria that do not get colored by gram-staining but rather remain colorless: they are neither Gram-positive nor Gram-negative...

Symbiotic bacteria are bacteria living in symbiosis with another organism or each other. For example, rhizobia living in root nodules of legumes provide...

microbiota, gut microbiome, or gut flora are the microorganisms, including bacteria, archaea, fungi, and viruses, that live in the digestive tracts of animals...

Denitrifying bacteria are a diverse group of bacteria that encompass many different phyla. This group of bacteria, together with denitrifying fungi and...

The evolution of bacteria has progressed over billions of years since the Precambrian time with their first major divergence from the archaeal/eukaryotic...

Exogenous bacteria are microorganisms introduced to closed biological systems from the external world.[citation needed] They exist in aquatic and terrestrial...

(bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants...

vitamin K2 or by preventing the colonization of the intestine by pathogenic bacteria. These mutually beneficial relationships between E. coli and humans are...

Indicator bacteria are types of bacteria used to detect and estimate the level of fecal contamination of water. They are not dangerous to human health...

oxygenated environment. Anaerobes may be unicellular (e.g. protozoans, bacteria) or multicellular. Most fungi are obligate aerobes, requiring oxygen to...

Electric bacteria are forms of bacteria that directly consume and excrete electrons at different energy potentials without requiring the metabolization...

Siderophilic bacteria are bacteria that require or are facilitated by free iron. They may include Vibrio vulnificus, Listeria monocytogenes, Yersinia...

methanogens lack peptidoglycan, a polymer that is found in the cell walls of Bacteria. Instead, some methanogens have a cell wall called pseudopeptidoglycan...

Saprotrophic bacteria are bacteria that are typically soil-dwelling and utilize saprotrophic nutrition as their primary energy source. They are often...

is a virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν (phagein), meaning "to devour"...

system that groups all cellular life into three domains, namely Archaea, Bacteria and Eukarya, introduced by Carl Woese, Otto Kandler and Mark Wheelis in...