Archaea & Bacteria
Even if you can't see them, that doesn't mean they're not there! Prokaryotes are one good example of why you can't always trust the naked eye to show you everything that's going on around you. Prokaryotes are single-celled organisms that can't be seen without the use of a microscope. Prokaryotic organisms fall into one of two groups: bacteria and archaea. Despite bacteria’s bad reputation as the cause of diseases in humans, animals, or plants, most bacteria are harmless, and they function as beneficial ecological agents. Archaea, too, fulfill important ecological roles in cold and temperate ecosystems. Without archaea and bacteria, our lives would be much more difficult: soil would not be fertile, and our ability to prepare certain foods, chemicals, and antibiotics would be hindered, among other difficulties.
Archaea & Bacteria Encyclopedia Articles
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François Jacob
François Jacob was a French biologist who, together with André Lwoff and Jacques Monod, was awarded the 1965 Nobel Prize for Physiology or Medicine for discoveries concerning regulatory activities in bacteria....
Bacillus thuringiensis
Bacillus thuringiensis (Bt), soil-dwelling bacterium that naturally produces a toxin that is fatal to certain herbivorous insects. The toxin produced by Bacillus thuringiensis (Bt) has been used as an...
bacteria
Bacteria, any of a group of microscopic single-celled organisms that live in enormous numbers in almost every environment on Earth, from deep-sea vents to deep below Earth’s surface to the digestive tracts...
blue-green algae
Blue-green algae, any of a large, heterogeneous group of prokaryotic, principally photosynthetic organisms. Cyanobacteria resemble the eukaryotic algae in many ways, including morphological characteristics...
Robert Koch
Robert Koch was a German physician and one of the founders of bacteriology. He discovered the anthrax disease cycle (1876) and the bacteria responsible for tuberculosis (1882) and cholera (1883). For his...
Carl Woese
Carl Woese was an American microbiologist who discovered the group of single-cell prokaryotic organisms known as archaea, which constitute a third domain of life. Woese attended Amherst College in Massachusetts,...
Ferdinand Cohn
Ferdinand Cohn was a German naturalist and botanist known for his studies of algae, bacteria, and fungi. He is considered one of the founders of bacteriology. Cohn was born in the ghetto of Breslau, the...
Frances Arnold
Frances Arnold is an American chemical engineer who was awarded the 2018 Nobel Prize for Chemistry for her work on directed evolution of enzymes. She shared the prize with American biochemist George P....
Antonie van Leeuwenhoek
Antonie van Leeuwenhoek was a Dutch microscopist who was the first to observe bacteria and protozoa. His researches on lower animals refuted the doctrine of spontaneous generation, and his observations...
Arthur Ashkin
Arthur Ashkin was an American physicist who was awarded the 2018 Nobel Prize for Physics for his invention of optical tweezers, which use laser beams to capture and manipulate very small objects. He shared...
Enterobacter
Enterobacter, (genus Enterobacter), any of a group of rod-shaped bacteria of the family Enterobacteriaceae. Enterobacter are gram-negative bacteria that are classified as facultative anaerobes, which means...
George P. Smith
George P. Smith is an American biochemist known for his development of phage display, a laboratory technique employing bacteriophages (bacteria-infecting viruses) for the investigation of protein-protein,...
MRSA
MRSA, bacterium in the genus Staphylococcus that is characterized by its resistance to the antibiotic methicillin and to related semisynthetic penicillins. MRSA is a strain of Staphylococcus aureus and...
staphylococcus
Staphylococcus, (genus Staphylococcus), group of spherical bacteria, the best-known species of which are universally present in great numbers on the mucous membranes and skin of humans and other warm-blooded...
Edward L. Tatum
Edward L. Tatum was an American biochemist who helped demonstrate that genes determine the structure of particular enzymes or otherwise act by regulating specific chemical processes in living things. His...
klebsiella
Klebsiella, (genus Klebsiella), any of a group of rod-shaped bacteria of the family Enterobacteriaceae. Klebsiella organisms are categorized microbiologically as gram-negative, facultative anaerobic, nonmotile...
Joshua Lederberg
Joshua Lederberg was an American geneticist and a pioneer in the field of bacterial genetics. He shared the 1958 Nobel Prize for Physiology or Medicine (with George W. Beadle and Edward L. Tatum) for discovering...
archaea
Archaea, (domain Archaea), any of a group of single-celled prokaryotic organisms (that is, organisms whose cells lack a defined nucleus) that have distinct molecular characteristics separating them from...
Yersinia
Yersinia, (genus Yersinia), any of a group of ovoid- or rod-shaped bacteria of the family Enterobacteriaceae. Yersinia are gram-negative bacteria and are described as facultative anaerobes, which means...
bacillus
Bacillus, (genus Bacillus), any of a genus of rod-shaped, gram-positive, aerobic or (under some conditions) anaerobic bacteria widely found in soil and water. The term bacillus has been applied in a general...
