Bacteria - Knowledge

4134: 3277: 798:, to energy. They live on and in plants and animals. Most do not cause diseases, are beneficial to their environments, and are essential for life. The soil is a rich source of bacteria and a few grams contain around a thousand million of them. They are all essential to soil ecology, breaking down toxic waste and recycling nutrients. They are even found in the atmosphere and one cubic metre of air holds around one hundred million bacterial cells. The oceans and seas harbour around 3 x 10 bacteria which provide up to 50% of the oxygen humans breathe. Only around 2% of bacterial species have been fully studied. 2180: 979: 3530: 296: 102: 3547: 684: 2821: 2954:, characterises bacteria based on the structural characteristics of their cell walls. The thick layers of peptidoglycan in the "Gram-positive" cell wall stain purple, while the thin "Gram-negative" cell wall appears pink. By combining morphology and Gram-staining, most bacteria can be classified as belonging to one of four groups (Gram-positive cocci, Gram-positive bacilli, Gram-negative cocci and Gram-negative bacilli). Some organisms are best identified by stains other than the Gram stain, particularly mycobacteria or 2200: 17514: 3040:" cells that are metabolically active but non-dividing. However, even using these improved methods, the total number of bacterial species is not known and cannot even be estimated with any certainty. Following present classification, there are a little less than 9,300 known species of prokaryotes, which includes bacteria and archaea; but attempts to estimate the true number of bacterial diversity have ranged from 10 to 10 total species—and even these diverse estimates may be off by many orders of magnitude. 3688: 2380: 131: 1202: 1550: 1671: 18081: 17392: 2554: 585: 1301: 2832: 1158:, migrate towards each other, and aggregate to form fruiting bodies up to 500 micrometres long and containing approximately 100,000 bacterial cells. In these fruiting bodies, the bacteria perform separate tasks; for example, about one in ten cells migrate to the top of a fruiting body and differentiate into a specialised dormant state called a myxospore, which is more resistant to drying and other adverse environmental conditions. 1100: 17402: 3312:" is derived from the word "commensal", meaning "eating at the same table" and all plants and animals are colonised by commensal bacteria. In humans and other animals, millions of them live on the skin, the airways, the gut and other orifices. Referred to as "normal flora", or "commensals", these bacteria usually cause no harm but may occasionally invade other sites of the body and cause infection. 2583: 1180:, through which there are networks of channels to enable better diffusion of nutrients. In natural environments, such as soil or the surfaces of plants, the majority of bacteria are bound to surfaces in biofilms. Biofilms are also important in medicine, as these structures are often present during chronic bacterial infections or in infections of 2482:. Mutation rates vary widely among different species of bacteria and even among different clones of a single species of bacteria. Genetic changes in bacterial genomes emerge from either random mutation during replication or "stress-directed mutation", where genes involved in a particular growth-limiting process have an increased mutation rate. 2922:, the Plant kingdom, and were called "Schizomycetes" (fission-fungi). For this reason, collective bacteria and other microorganisms in a host are often called "flora". The term "bacteria" was traditionally applied to all microscopic, single-cell prokaryotes. However, molecular systematics showed prokaryotic life to consist of two separate 4164:. Bacteria were Leeuwenhoek's most remarkable microscopic discovery. Their size was just at the limit of what his simple lenses could resolve, and, in one of the most striking hiatuses in the history of science, no one else would see them again for over a century. His observations also included protozoans which he called 2575:, long filaments that are turned by a motor at the base to generate propeller-like movement. The bacterial flagellum is made of about 20 proteins, with approximately another 30 proteins required for its regulation and assembly. The flagellum is a rotating structure driven by a reversible motor at the base that uses the 2930:, which is currently the most widely used classification system in microbiology. However, due to the relatively recent introduction of molecular systematics and a rapid increase in the number of genome sequences that are available, bacterial classification remains a changing and expanding field. For example, 2880:. While these schemes allowed the identification and classification of bacterial strains, it was unclear whether these differences represented variation between distinct species or between strains of the same species. This uncertainty was due to the lack of distinctive structures in most bacteria, as well as 2926:, originally called Eubacteria and Archaebacteria, but now called Bacteria and Archaea that evolved independently from an ancient common ancestor. The archaea and eukaryotes are more closely related to each other than either is to the bacteria. These two domains, along with Eukarya, are the basis of the 4230:

had realised the importance of sanitised hands in medical work. Semmelweis, who in the 1840s formulated his rules for handwashing in the hospital, prior to the advent of germ theory, attributed disease to "decomposing animal organic matter". His ideas were rejected and his book on the topic condemned

3381:

archaea that consume hydrogen. The bacteria in this association are unable to consume the organic acids as this reaction produces hydrogen that accumulates in their surroundings. Only the intimate association with the hydrogen-consuming archaea keeps the hydrogen concentration low enough to allow the

2529:

In ordinary circumstances, transduction, conjugation, and transformation involve transfer of DNA between individual bacteria of the same species, but occasionally transfer may occur between individuals of different bacterial species, and this may have significant consequences, such as the transfer of

2279:

Most laboratory techniques for growing bacteria use high levels of nutrients to produce large amounts of cells cheaply and quickly. However, in natural environments, nutrients are limited, meaning that bacteria cannot continue to reproduce indefinitely. This nutrient limitation has led the evolution

2275:

pure cultures of a bacterial strain. However, liquid growth media are used when the measurement of growth or large volumes of cells are required. Growth in stirred liquid media occurs as an even cell suspension, making the cultures easy to divide and transfer, although isolating single bacteria from

7581:

Beveridge TJ, Pouwels PH, Sára M, Kotiranta A, Lounatmaa K, Kari K, Kerosuo E, Haapasalo M, Egelseer EM, Schocher I, Sleytr UB, Morelli L, Callegari ML, Nomellini JF, Bingle WH, Smit J, Leibovitz E, Lemaire M, Miras I, Salamitou S, Béguin P, Ohayon H, Gounon P, Matuschek M, Koval SF (June 1997).

2493:

take up DNA from the environment, while others must be chemically altered in order to induce them to take up DNA. The development of competence in nature is usually associated with stressful environmental conditions and seems to be an adaptation for facilitating repair of DNA damage in recipient

2757:, accessing resources that cannot effectively be used by single cells, collectively defending against antagonists, and optimising population survival by differentiating into distinct cell types. For example, bacteria in biofilms can have more than five hundred times increased resistance to 781:

Bacteria are ubiquitous, living in every possible habitat on the planet including soil, underwater, deep in Earth's crust and even such extreme environments as acidic hot springs and radioactive waste. There are thought to be approximately 2×10 bacteria on Earth, forming a

7971:

Jernigan JA, Stephens DS, Ashford DA, Omenaca C, Topiel MS, Galbraith M, Tapper M, Fisk TL, Zaki S, Popovic T, Meyer RF, Quinn CP, Harper SA, Fridkin SK, Sejvar JJ, Shepard CW, McConnell M, Guarner J, Shieh WJ, Malecki JM, Gerberding JL, Hughes JM, Perkins BA (2001).

3344:

that kill and digest any bacteria they encounter. Other bacterial predators either attach to their prey in order to digest them and absorb nutrients or invade another cell and multiply inside the cytosol. These predatory bacteria are thought to have evolved from

2314:, a period of slow growth when the cells are adapting to the high-nutrient environment and preparing for fast growth. The lag phase has high biosynthesis rates, as proteins necessary for rapid growth are produced. The second phase of growth is the 12509:

Shiao SL, Kershaw KM, Limon JJ, You S, Yoon J, Ko EY, Guarnerio J, Potdar AA, McGovern DP, Bose S, Dar TB, Noe P, Lee J, Kubota Y, Maymi VI, Davis MJ, Henson RM, Choi RY, Yang W, Tang J, Gargus M, Prince AD, Zumsteg ZS, Underhill DM (July 2021).

1492:(previously known as the low G+C and high G+C Gram-positive bacteria, respectively) have the alternative Gram-positive arrangement. These differences in structure can produce differences in antibiotic susceptibility; for instance, 2344:

and is caused by depleted nutrients. The cells reduce their metabolic activity and consume non-essential cellular proteins. The stationary phase is a transition from rapid growth to a stress response state and there is increased

1289:. However, in many photosynthetic bacteria, the plasma membrane is highly folded and fills most of the cell with layers of light-gathering membrane. These light-gathering complexes may even form lipid-enclosed structures called 2772:, which serves the purpose of determining whether the local population density is sufficient to support investment in processes that are only successful if large numbers of similar organisms behave similarly, such as excreting 2687:. In one peculiar group, the myxobacteria, individual bacteria move together to form waves of cells that then differentiate to form fruiting bodies containing spores. The myxobacteria move only when on solid surfaces, unlike 2976:

techniques are designed to promote the growth and identify particular bacteria while restricting the growth of the other bacteria in the sample. Often these techniques are designed for specific specimens; for example, a

3572:

matter. The blood and tissue fluids contain nutrients sufficient to sustain the growth of many bacteria. The body has defence mechanisms that enable it to resist microbial invasion of its tissues and give it a natural

2941:, where the correct treatment is determined by the bacterial species causing an infection. Consequently, the need to identify human pathogens was a major impetus for the development of techniques to identify bacteria. 2245:

daughter cells are produced. Some bacteria, while still reproducing asexually, form more complex reproductive structures that help disperse the newly formed daughter cells. Examples include fruiting body formation by

2884:

between unrelated species. Due to lateral gene transfer, some closely related bacteria can have very different morphologies and metabolisms. To overcome this uncertainty, modern bacterial classification emphasises

3739:

and death. Yet these organisms are also part of the normal human flora and usually exist on the skin or in the nose without causing any disease at all. Other organisms invariably cause disease in humans, such as

1587:") are fine filaments of protein, usually 2–10 nanometres in diameter and up to several micrometres in length. They are distributed over the surface of the cell, and resemble fine hairs when seen under the 722:

prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species. However, gene sequences can be used to reconstruct the bacterial

18907: 297: 3397:, converting nitrogen gas to nitrogenous compounds. This serves to provide an easily absorbable form of nitrogen for many plants, which cannot fix nitrogen themselves. Many other bacteria are found as 8295:

Nicholson WL, Schuerger AC, Setlow P (April 2005). "The solar UV environment and bacterial spore UV resistance: considerations for Earth-to-Mars transport by natural processes and human spaceflight".

2213: 1652:. These transfer proteins from the cytoplasm into the periplasm or into the environment around the cell. Many types of secretion systems are known and these structures are often essential for the 1438:, respectively. The cell wall of bacteria is also distinct from that of achaea, which do not contain peptidoglycan. The cell wall is essential to the survival of many bacteria, and the antibiotic 3009:, are cultured under conditions designed to grow all possible organisms. Once a pathogenic organism has been isolated, it can be further characterised by its morphology, growth patterns (such as 2310:

follows four phases. When a population of bacteria first enter a high-nutrient environment that allows growth, the cells need to adapt to their new environment. The first phase of growth is the

710:

to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life. Although bacterial

1254:

and the other organelles present in eukaryotic cells. However, some bacteria have protein-bound organelles in the cytoplasm which compartmentalise aspects of bacterial metabolism, such as the

4071:

in bacteria, then apply this knowledge to more complex organisms. This aim of understanding the biochemistry of a cell reaches its most complex expression in the synthesis of huge amounts of

2300:) that may allow for increased supply of nutrients and protection from environmental stresses. These relationships can be essential for growth of a particular organism or group of organisms ( 3592:

If bacteria form a parasitic association with other organisms, they are classed as pathogens. Pathogenic bacteria are a major cause of human death and disease and cause infections such as

3357:

Certain bacteria form close spatial associations that are essential for their survival. One such mutualistic association, called interspecies hydrogen transfer, occurs between clusters of

9513:

Pradella S, Hans A, Spröer C, Reichenbach H, Gerth K, Beyer S (December 2002). "Characterisation, genome size and genetic manipulation of the myxobacterium Sorangium cellulosum So ce56".

8820:

Kosugi Y, Matsuura N, Liang Q, Yamamoto-Ikemoto R (October 2020). "Wastewater Treatment using the "Sulfate Reduction, DenitrificationAnammox and Partial Nitrification (SRDAPN)" Process".

2241:. Under optimal conditions, bacteria can grow and divide extremely rapidly, and some bacterial populations can double as quickly as every 17 minutes. In cell division, two identical 2455:

Bacteria genomes usually encode a few hundred to a few thousand genes. The genes in bacterial genomes are usually a single continuous stretch of DNA. Although several different types of

1154:

species. These multicellular structures are often only seen in certain conditions. For example, when starved of amino acids, myxobacteria detect surrounding cells in a process known as

7770:

Costa TR, Felisberto-Rodrigues C, Meir A, Prevost MS, Redzej A, Trokter M, Waksman G (June 2015). "Secretion systems in Gram-negative bacteria: structural and mechanistic insights".

18900: 738:

Bacteria were also involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into

14299: 2518:

sequences to retain fragments of the genomes of phage that the bacteria have come into contact with in the past, which allows them to block virus replication through a form of

2485:

Some bacteria transfer genetic material between cells. This can occur in three main ways. First, bacteria can take up exogenous DNA from their environment in a process called

14436: 3877:

measures such as sterilising the skin prior to piercing it with the needle of a syringe, and by proper care of indwelling catheters. Surgical and dental instruments are also

10095:

Barrangou R, Fremaux C, Deveau H, Richards M, Boyaval P, Moineau S, Romero DA, Horvath P (March 2007). "CRISPR provides acquired resistance against viruses in prokaryotes".

6746:

Norris V, den Blaauwen T, Cabin-Flaman A, Doi RH, Harshey R, Janniere L, Jimenez-Sanchez A, Jin DJ, Levin PA, Mileykovskaya E, Minsky A, Saier M, Skarstad K (March 2007).

2276:

liquid media is difficult. The use of selective media (media with specific nutrients added or deficient, or with antibiotics added) can help identify specific organisms.

18893: 7872:"The glycan-rich outer layer of the cell wall of Mycobacterium tuberculosis acts as an antiphagocytic capsule limiting the association of the bacterium with macrophages" 6060: 2860:

seeks to describe the diversity of bacterial species by naming and grouping organisms based on similarities. Bacteria can be classified on the basis of cell structure,

16322: 2907:. Classification of bacteria is determined by publication in the International Journal of Systematic Bacteriology, and Bergey's Manual of Systematic Bacteriology. The 8132:

Nicholson WL, Fajardo-Cavazos P, Rebeil R, Slieman TA, Riesenman PJ, Law JF, Xue Y (August 2002). "Bacterial endospores and their significance in stress resistance".

2658:, that uses other mechanisms. In twitching motility, the rod-like pilus extends out from the cell, binds some substrate, and then retracts, pulling the cell forward. 1899:. Chemotrophs are further divided by the types of compounds they use to transfer electrons. Bacteria that derive electrons from inorganic compounds such as hydrogen, 742:

associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea. This involved the engulfment by proto-eukaryotic cells of

6587:

Kerfeld CA, Sawaya MR, Tanaka S, Nguyen CV, Phillips M, Beeby M, Yeates TO (August 2005). "Protein structures forming the shell of primitive bacterial organelles".

2338:). During log phase, nutrients are metabolised at maximum speed until one of the nutrients is depleted and starts limiting growth. The third phase of growth is the 16774: 16414: 3649: 3318:

is a commensal in the human gut but can cause urinary tract infections. Similarly, streptococci, which are part of the normal flora of the human mouth, can cause

19654: 15686: 10302: 9470:

Nakabachi A, Yamashita A, Toh H, Ishikawa H, Dunbar HE, Moran NA, Hattori M (October 2006). "The 160-kilobase genome of the bacterial endosymbiont Carsonella".

9324:

Prats C, López D, Giró A, Ferrer J, Valls J (August 2006). "Individual-based modelling of bacterial cultures to study the microscopic causes of the lag phase".

6544:

Yeates TO, Kerfeld CA, Heinhorst S, Cannon GC, Shively JM (September 2008). "Protein-based organelles in bacteria: carboxysomes and related microcompartments".

3036:, are increasingly popular due to their specificity and speed, compared to culture-based methods. These methods also allow the detection and identification of " 1523:

of rigidly arrayed protein molecules covers the outside of the cell. This layer provides chemical and physical protection for the cell surface and can act as a

16599: 15806: 15786: 15270: 7022: 6205:

Mandal A, Dutta A, Das R, Mukherjee J (June 2021). "Role of intertidal microbial communities in carbon dioxide sequestration and pollutant removal: A review".

11229:

Boucher Y, Douady CJ, Papke RT, Walsh DA, Boudreau ME, Nesbø CL, Case RJ, Doolittle WF (2003). "Lateral gene transfer and the origins of prokaryotic groups".

16238: 16139: 12874:"Cross-protection from hydrogen peroxide by helper microbes: the impacts on the cyanobacterium Prochlorococcus and other beneficiaries in marine communities" 16132: 16113: 15940: 15860: 15639: 12610:

Eleyan L, Khan AA, Musollari G, Chandiramani AS, Shaikh S, Salha A, Tarmahomed A, Harky A (April 2021). "Infective endocarditis in paediatric population".

1591:. Fimbriae are believed to be involved in attachment to solid surfaces or to other cells, and are essential for the virulence of some bacterial pathogens. 1512:. Some bacteria have cell wall structures that are neither classically Gram-positive or Gram-negative. This includes clinically important bacteria such as 8338: 17722: 16700: 16526: 16502: 16473: 16360: 16284: 16168: 16146: 15387: 14661: 2122: 993:. Bacteria display a wide diversity of shapes and sizes. Bacterial cells are about one-tenth the size of eukaryotic cells and are typically 0.5–5.0 16406: 16250: 15872: 15835: 15813: 15722: 15710: 8910:"How to define obligatory anaerobiosis? An evolutionary view on the antioxidant response system and the early stages of the evolution of life on Earth" 8625: 2908: 1084:. A small number of other unusual shapes have been described, such as star-shaped bacteria. This wide variety of shapes is determined by the bacterial 13895:

Bozsik A (July 2006). "Susceptibility of adult Coccinella septempunctata (Coleoptera: Coccinellidae) to insecticides with different modes of action".

11367:

Hedlund BP, Dodsworth JA, Staley JT (June 2015). "The changing landscape of microbial biodiversity exploration and its implications for systematics".

1388:, which they use to regulate their buoyancy, allowing them to move up or down into water layers with different light intensities and nutrient levels. 1172:. These biofilms and mats can range from a few micrometres in thickness to up to half a metre in depth, and may contain multiple species of bacteria, 16606: 16488: 16382: 15698: 15627: 15221: 15184: 15132: 14933: 12829:

Stams AJ, de Bok FA, Plugge CM, van Eekert MH, Dolfing J, Schraa G (March 2006). "Exocellular electron transfer in anaerobic microbial communities".

9975:

Bernstein H, Bernstein C, Michod RE (2012). "DNA repair as the primary adaptive function of sex in bacteria and eukaryotes". Chapter 1: pp. 1–49 in:

2394:. Some of the attached phage have contracted tails indicating that they have injected their DNA into the host. The bacterial cells are ~ 0.5 μm wide. 1176:

and archaea. Bacteria living in biofilms display a complex arrangement of cells and extracellular components, forming secondary structures, such as

18411: 16272: 16101: 15891: 15853: 14024:

Almaas E, Kovács B, Vicsek T, Oltvai ZN, Barabási AL (February 2004). "Global organization of metabolic fluxes in the bacterium Escherichia coli".

5100: 7057: 16781: 16223: 16153: 15765: 4051:

Because of their ability to quickly grow and the relative ease with which they can be manipulated, bacteria are the workhorses for the fields of

735:

that lived about 2.5 billion–3.2 billion years ago. The earliest life on land may have been bacteria some 3.22 billion years ago.

8175:

Vreeland RH, Rosenzweig WD, Powers DW (October 2000). "Isolation of a 250 million-year-old halotolerant bacterium from a primary salt crystal".

7672:"Recent Advances in Our Understanding of the Diversity and Roles of Chaperone-Usher Fimbriae in Facilitating Salmonella Host and Tissue Tropism" 16762: 16688: 16120: 5721:

Volland JM, Gonzalez-Rizzo S, Gros O, Tyml T, Ivanova N, Schulz F, Goudeau D, Elisabeth NH, Nath N, Udwary D, Malmstrom RR (18 February 2022).

2912: 2292:

blooms that often occur in lakes during the summer. Other organisms have adaptations to harsh environments, such as the production of multiple

1726:. Endospores develop within the cytoplasm of the cell; generally, a single endospore develops in each cell. Each endospore contains a core of 19680: 16797: 16514: 16306: 16211: 15903: 15753: 15737: 15299: 15075: 12561:"MALT Lymphoma of the Urinary Bladder Shows a Dramatic Female Predominance, Uneven Geographic Distribution, and Possible Infectious Etiology" 1015:

can reach even 2 cm in length, which is 50 times larger than other known bacteria. Among the smallest bacteria are members of the genus

14549: 1761:. In this dormant state, these organisms may remain viable for millions of years. Endospores even allow bacteria to survive exposure to the 1092:

and is important because it can influence the ability of bacteria to acquire nutrients, attach to surfaces, swim through liquids and escape

14414: 12081: 7122:

Kadouri D, Jurkevitch E, Okon Y, Castro-Sowinski S (2005). "Ecological and agricultural significance of bacterial polyhydroxyalkanoates".

1470:. In contrast, Gram-negative bacteria have a relatively thin cell wall consisting of a few layers of peptidoglycan surrounded by a second 425:, though there are many on the skin. Most of the bacteria in and on the body are harmless or rendered so by the protective effects of the 19463: 14462: 3025: 621: 10156:

Brouns SJ, Jore MM, Lundgren M, Westra ER, Slijkhuis RJ, Snijders AP, Dickman MJ, Makarova KS, Koonin EV, van der Oost J (August 2008).

7071:

Brune DC (June 1995). "Isolation and characterization of sulfur globule proteins from Chromatium vinosum and Thiocapsa roseopersicina".

6993:"The interplay of glycogen metabolism and differentiation provides an insight into the developmental biology of Streptomyces coelicolor" 16461: 15928: 10939: 3853:

a process that is different in the pathogen from that found in the host. An example of how antibiotics produce selective toxicity are

18061: 18051: 15464: 14531: 4133: 4087:

metabolism now being produced and tested. This understanding of bacterial metabolism and genetics allows the use of biotechnology to

1132:

group together in "bunch of grapes" clusters. Bacteria can also group to form larger multicellular structures, such as the elongated

4998:"A genomic timescale of prokaryote evolution: insights into the origin of methanogenesis, phototrophy, and the colonization of land" 4892:

Daum B, Gold V (June 2018). "Twitch or swim: towards the understanding of prokaryotic motion based on the type IV pilus blueprint".

2117:. This trait, which can be found in bacteria of most metabolic types listed above, leads to the ecologically important processes of 19615: 17438: 14444: 8873: 2739:

often occurs in bacteria that live in association with fish, and the light probably serves to attract fish or other large animals.

9232:

Kooijman SA, Auger P, Poggiale JC, Kooi BW (August 2003). "Quantitative steps in symbiogenesis and the evolution of homeostasis".

639: 19641: 18117: 17837: 17812: 9175:"Synergy and contingency as driving forces for the evolution of multiple secondary metabolite production by Streptomyces species" 8226:

Cano RJ, Borucki MK (May 1995). "Revival and identification of bacterial spores in 25- to 40-million-year-old Dominican amber".

4063:. By making mutations in bacterial DNA and examining the resulting phenotypes, scientists can determine the function of genes, 2966:

or similar stains. Other organisms may need to be identified by their growth in special media, or by other techniques, such as

19030: 1565:

are rigid protein structures, about 20 nanometres in diameter and up to 20 micrometres in length, that are used for

14926: 14882: 14863: 14836: 14809: 14782: 14755: 13780:

Neves LC, Miyamura TT, Moraes DA, Penna TC, Converti A (2006). "Biofiltration methods for the removal of phenolic residues".

12308: 11046: 9984: 9384: 7634: 6442: 5890: 4247: 2838:

showing the diversity of bacteria, compared to other organisms. Here bacteria are represented by three main supergroups: the

5048: 3889:

are used to kill bacteria or other pathogens on surfaces to prevent contamination and further reduce the risk of infection.

2911:(ICSB) maintains international rules for the naming of bacteria and taxonomic categories and for the ranking of them in the 17858: 17331: 16805: 12066: 4522: 1734:

surrounded by a cortex layer and protected by a multilayer rigid coat composed of peptidoglycan and a variety of proteins.

406:

relationships with plants and animals. Most bacteria have not been characterised and there are many species that cannot be

13549:"Ribosomal crystallography: initiation, peptide bond formation, and amino acid polymerization are hampered by antibiotics" 4556: 3956:

The ability of bacteria to degrade a variety of organic compounds is remarkable and has been used in waste processing and

2296:

by Streptomyces that inhibit the growth of competing microorganisms. In nature, many organisms live in communities (e.g.,

19396: 10488:"Collective bacterial dynamics revealed using a three-dimensional population-scale defocused particle tracking technique" 3560:

The body is continually exposed to many species of bacteria, including beneficial commensals, which grow on the skin and

19646: 11916:

Alizadeh M, Yousefi L, Pakdel F, Ghotaslou R, Rezaee MA, Khodadadi E, Oskouei MA, Soroush Barhaghi MH, Kafil HS (2021).

5159: 1853:, but these traits often do not correspond with modern genetic classifications. Bacterial metabolism is classified into 18046: 17098: 16838: 4293:—into compounds that selectively killed the pathogen. Ehrlich, who had been awarded a 1908 Nobel Prize for his work on 1825: 1621:

is produced by many bacteria to surround their cells, and varies in structural complexity: ranging from a disorganised

761:, e.g. in ancient "amitochondrial" protozoa). Later, some eukaryotes that already contained mitochondria also engulfed 11609:"The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification" 10263: 19453: 14399:] (in German). Berlin: Physikalische Abhandlungen der Koeniglichen Akademie der Wissenschaften. pp. 143–336. 14179:

Graumann K, Premstaller A (February 2006). "Manufacturing of recombinant therapeutic proteins in microbial systems".

12112: 10319:

Hastings PJ, Rosenberg SM, Slack A (September 2004). "Antibiotic-induced lateral transfer of antibiotic resistance".

9611:

Lin YS, Kieser HM, Hopwood DA, Chen CW (December 1993). "The chromosomal DNA of Streptomyces lividans 66 is linear".

7483: 3865:, but not the structurally different eukaryotic ribosome. Antibiotics are used both in treating human disease and in 1626: 1281:

difference analogous to a battery. The general lack of internal membranes in bacteria means these reactions, such as

9425:"Imaging Bacterial Colonies and Phage-Bacterium Interaction at Sub-Nanometer Resolution Using Helium-Ion Microscopy" 6992: 1516:

which have a thick peptidoglycan cell wall like a Gram-positive bacterium, but also a second outer layer of lipids.

19739: 19458: 17873: 17853: 14971: 14919: 8372: 6844:"Lamellar organization of pigments in chlorosomes, the light harvesting complexes of green photosynthetic bacteria" 3983:. These efforts were effective on beaches that were not too thickly covered in oil. Bacteria are also used for the 1849:

types. The distribution of metabolic traits within a group of bacteria has traditionally been used to define their

969: 2586:

The different arrangements of bacterial flagella: A-Monotrichous; B-Lophotrichous; C-Amphitrichous; D-Peritrichous

17088: 17015: 14966: 8720:

Imran A, Hakim S, Tariq M, Nawaz MS, Laraib I, Gulzar U, Hanif MK, Siddique MJ, Hayat M, Fraz A, Ahmad M (2021).

3747: 3319: 2511: 2260:

species, or budding. Budding involves a cell forming a protrusion that breaks away and produces a daughter cell.

973: 560:

changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that

4106:

Because of their importance for research in general, samples of bacterial strains are isolated and preserved in

3642:). A pathogenic cause for a known medical disease may only be discovered many years later, as was the case with 19381: 17212: 16943: 4741:"Disparate rates, differing fates: tempo and mode of evolution changed from the Precambrian to the Phanerozoic" 4127: 2383: 699: 565: 19685: 14657: 4032:

under trade names such as Dipel and Thuricide. Because of their specificity, these pesticides are regarded as

3446:. The presence of this gut flora also inhibits the growth of potentially pathogenic bacteria (usually through 19369: 17957: 17822: 15050: 15040: 15023: 13553: 11529: 11129: 10994: 10947: 7922:

Kalscheuer R, Palacios A, Anso I, Cifuente J, Anguita J, Jacobs WR, Guerin ME, Prados-Rosales R (July 2019).

6158: 6118: 4345: 4175: 3349:

that consumed dead microorganisms, through adaptations that allowed them to entrap and kill other organisms.

2721:

at one pole of their cells, they can form a kind of tail that pushes them through the host cell's cytoplasm.

2596:) have two distinct modes of movement: forward movement (swimming) and tumbling. The tumbling allows them to 1645:

and be involved in cell recognition, as well as aiding attachment to surfaces and the formation of biofilms.

1327: 1310: 9277:"Lag Phase is a Dynamic, Organized, Adaptive, and Evolvable Period that Prepares Bacteria for Cell Division" 2590:

Bacteria can use flagella in different ways to generate different kinds of movement. Many bacteria (such as

19782: 17555: 17513: 17431: 4945:

Di Giulio M (December 2003). "The universal ancestor and the ancestor of bacteria were hyperthermophiles".

3878: 3759: 2412: 674: 109: 13856:"Why Bacillus thuringiensis insecticidal toxins are so effective: unique features of their mode of action" 13238:"Helicobacter pylori infection causes both protective and deleterious effects in human health and disease" 3024:

As with bacterial classification, identification of bacteria is increasingly using molecular methods, and

2607:. Bacterial species differ in the number and arrangement of flagella on their surface; some have a single 18110: 17898: 12373: 11319: 6458:

Feijoo-Siota L, Rama JL, Sánchez-Pérez A, Villa TG (July 2017). "Considerations on bacterial nucleoids".

5846:"Nanobacteria, Ultramicrobacteria and Starvation Forms: A Search for the Smallest Metabolizing Bacterium" 4587: 4539: 4370: 4271:

Though it was known in the nineteenth century that bacteria are the cause of many diseases, no effective

4107: 3790: 2150: 1618: 1542: 728: 502: 12559:

Lyapichev KA, Ivashkevich Y, Chernov Y, Chinenov D, Shpot E, Bessonov AA, Dabaja BS, Konoplev S (2021).

5136: 2530:

antibiotic resistance. In such cases, gene acquisition from other bacteria or the environment is called

1262:

to control the localisation of proteins and nucleic acids within the cell, and to manage the process of

19777: 17928: 17817: 17643: 17615: 17053: 14410: 7037: 4568: 4534: 3638: 3401: 2444:, small extra-chromosomal molecules of DNA that may contain genes for various useful functions such as 2362: 2340: 2315: 2311: 2284:). Some organisms can grow extremely rapidly when nutrients become available, such as the formation of 2162: 1892: 1854: 1649: 945: 11968: 11867:"The Loop-Mediated Isothermal Amplification Technique in Periodontal Diagnostics: A Systematic Review" 9999:"Phages and the evolution of bacterial pathogens: from genomic rearrangements to lysogenic conversion" 7392: 6116:

Shimkets LJ (1999). "Intercellular signaling during fruiting-body development of Myxococcus xanthus".

6085: 4231:

by the medical community. After Lister, however, doctors started sanitising their hands in the 1870s.

3284:

Despite their apparent simplicity, bacteria can form complex associations with other organisms. These

2233:

are tightly linked in unicellular organisms. Bacteria grow to a fixed size and then reproduce through

1354:

for the production of proteins, but the structure of the bacterial ribosome is different from that of

19695: 18885: 18254: 17405: 15455: 12324:

Mushegian AA, Ebert D (January 2016). "Rethinking "mutualism" in diverse host-symbiont communities".

11345: 11231: 11174:"Phylogenomics of 10,575 genomes reveals evolutionary proximity between domains Bacteria and Archaea" 10790: 9655: 7815:"Dismantling the bacterial glycocalyx: Chemical tools to probe, perturb, and image bacterial glycans" 7038:"Inorganic polyphosphate and polyphosphate kinase: their novel biological functions and applications" 5420:

Flemming HC, Wuertz S (April 2019). "Bacteria and archaea on Earth and their abundance in biofilms".

5047:

Homann M, Sansjofre P, Van Zuilen M, Heubeck C, Gong J, Killingsworth B, et al. (23 July 2018).

3271: 3033: 2857: 2803: 2510:

bacteria, while others insert into the bacterial chromosome. Bacteria resist phage infection through

2486: 2134: 1451:

There are broadly speaking two different types of cell wall in bacteria, that classify bacteria into

1278: 999: 707: 670: 613: 557: 130: 38: 17: 11488: 9087:

Thomson RB, Bertram H (December 2001). "Laboratory diagnosis of central nervous system infections".

8418:

Reigadas E, van Prehn J, Falcone M, Fitzpatrick F, Vehreschild MJ, Kuijper EJ, Bouza E (July 2021).

6609: 5229:

Dyall SD, Brown MT, Johnson PJ (April 2004). "Ancient invasions: from endosymbionts to organelles".

4812: 4297:, pioneered the use of stains to detect and identify bacteria, with his work being the basis of the 4024:(also called BT), a Gram-positive, soil-dwelling bacterium. Subspecies of this bacteria are used as 1187:, and bacteria protected within biofilms are much harder to kill than individual isolated bacteria. 727:, and these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. The 19726: 19440: 19386: 17947: 17658: 17207: 17130: 17093: 16889: 10992:

Costerton JW, Lewandowski Z, Caldwell DE, Korber DR, Lappin-Scott HM (1995). "Microbial biofilms".

10578:

Merz AJ, So M, Sheetz MP (September 2000). "Pilus retraction powers bacterial twitching motility".

6948:

Poehlsgaard J, Douthwaite S (November 2005). "The bacterial ribosome as a target for antibiotics".

5882: 4033: 3784: 3768:, another phylum of obligate intracellular parasites, contains species that can cause pneumonia or 3673: 3404:

and other organisms. For example, the presence of over 1,000 bacterial species in the normal human

3037: 3018: 2631: 2625: 2619: 2613: 2576: 2531: 2272: 1611:

or sex pili (see bacterial genetics, below). They can also generate movement where they are called

1574: 1282: 1259: 1196: 790:

where they provide the nutrients needed to sustain life by converting dissolved compounds, such as

6807:

Bryant DA, Frigaard NU (November 2006). "Prokaryotic photosynthesis and phototrophy illuminated".

4268:, studying bacteria from 1870. Cohn was the first to classify bacteria based on their morphology. 4246:. In his research into tuberculosis, Koch finally proved the germ theory, for which he received a 421:

Like all animals, humans carry vast numbers (approximately 10 to 10) of bacteria. Most are in the

19475: 18339: 18084: 17998: 17993: 17888: 17802: 17550: 17424: 16618: 15055: 14564: 13592:"Agricultural use of antibiotics and the evolution and transfer of antibiotic-resistant bacteria" 12680:

Velicer GJ, Stredwick KL (August 2002). "Experimental social evolution with Myxococcus xanthus".

9423:

Leppänen M, Sundberg LR, Laanto E, de Freitas Almeida GM, Papponen P, Maasilta IJ (August 2017).

8522:"Microbial ecology in the age of genomics and metagenomics: concepts, tools, and recent advances" 4302: 4161: 4153: 4137: 4015: 3795: 3769: 3492: 3243: 3029: 2997:

while preventing growth of non-pathogenic bacteria. Specimens that are normally sterile, such as

2973: 2571:(able to move themselves) and do so using a variety of mechanisms. The best studied of these are 2499: 2051: 1790: 1011: 1005: 858: 407: 386:

bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as

19744: 14397:

Third contribution to the knowledge of great organization in the direction of the smallest space

11822:

Riley LW (November 2018). "Laboratory Methods in Molecular Epidemiology: Bacterial Infections".

7924:"The Mycobacterium tuberculosis capsule: a cell structure with key implications in pathogenesis" 4619:"Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya" 19519: 18103: 18039: 17983: 17540: 17530: 17283: 17202: 17181: 16831: 12097: 11483: 10394:

Kim KW (December 2017). "Electron microscopic observations of prokaryotic surface appendages".

8469:

Nealson KH (January 1999). "Post-Viking microbiology: new approaches, new data, new insights".

6604: 4807: 4219: 4199: 4020: 4000: 3977: 3778: 3773: 3552: 2559: 2129:, respectively. Bacterial metabolic processes are important drivers in biological responses to 1580: 1508: 1502: 1456: 1452: 14458: 11726:"Assessment and Comparison of Molecular Subtyping and Characterization Methods for Salmonella" 8673:"The Leeuwenhoek Lecture 2000 the natural and unnatural history of methane-oxidizing bacteria" 6842:

Psencík J, Ikonen TP, Laurinmäki P, Merckel MC, Butcher SJ, Serimaa RE, Tuma R (August 2004).

5722: 3330:

Some species of bacteria kill and then consume other microorganisms; these species are called

19772: 18567: 18217: 18029: 17973: 17878: 17777: 17653: 17586: 17323: 16965: 15018: 7974:"Bioterrorism-related inhalational anthrax: the first 10 cases reported in the United States" 4312:

recognised that archaea have a separate line of evolutionary descent from bacteria. This new

3870: 3820: 3764: 3534: 3504: 3500: 3447: 3386: 2931: 2886: 2881: 2662: 2523: 2471: 2445: 2022: 1604: 1466:

Gram-positive bacteria possess a thick cell wall containing many layers of peptidoglycan and

1374: 1294: 1118:. Most bacterial species exist as single cells; others associate in characteristic patterns: 770: 678: 664: 482: 470: 359: 19708: 10972: 8871:

Morel FM, Kraepiel AM, Amyot M (1998). "The chemical cycle and bioaccumulation of mercury".

8023:"Resistance of Bacillus endospores to extreme terrestrial and extraterrestrial environments" 6061:"Bacterial solutions to multicellularity: a tale of biofilms, filaments and fruiting bodies" 3589:, bacteria evolve relatively slowly so many bacterial diseases also occur in other animals. 3276: 1072:, are shaped like slightly curved rods or comma-shaped; others can be spiral-shaped, called 19589: 19485: 18232: 17935: 17648: 17545: 17163: 17038: 17021: 16859: 16669: 15604: 14696: 14239: 14043: 13644: 13567: 13548: 12885: 12838: 12785: 12512:"Commensal bacteria and fungi differentially regulate tumor responses to radiation therapy" 12474:

Roscoe DL, Chow AW (March 1988). "Normal flora and mucosal immunity of the head and neck".

12155: 11983: 11542: 11376: 11244: 11185: 10740: 10683: 10587: 10556: 10499: 10278: 10169: 10104: 9522: 9333: 9186: 8829: 8784: 8478: 8304: 8235: 8184: 7080: 6855: 6596: 6501:

Bobik TA (May 2006). "Polyhedral organelles compartmenting bacterial metabolic processes".

6214: 6171: 5476: 5238: 5065: 4954: 4752: 4630: 4340: 4251: 3973: 3898: 3849:

if they just prevent bacterial growth. There are many types of antibiotics, and each class

3628: 3143: 3055: 2498:

can integrate into the bacterial chromosome, introducing foreign DNA in a process known as

2418: 2281: 2238: 2158: 2102: 1840: 1230:. This membrane encloses the contents of the cell and acts as a barrier to hold nutrients, 1133: 983: 786:

that is only exceeded by plants. They are abundant in lakes and oceans, in arctic ice, and

719: 14524: 13698: 13681: 7321:(1884). "Über die isolierte Färbung der Schizomyceten in Schnitt- und Trockenpräparaten". 5908:"Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments" 4475: 4458: 3695:, beneficial bacteria in the vagina (top) are displaced by pathogens (bottom). Gram stain. 3341: 8: 19060: 17751: 17288: 17173: 17168: 17061: 17031: 16884: 16869: 16675: 16430: 15609: 14393:

Dritter Beitrag zur Erkenntniss grosser Organisation in der Richtung des kleinsten Raumes

13734: 11969:"Novel Microbial Diversity and Functional Potential in the Marine Mammal Oral Microbiome" 11172:

Zhu Q, Mai U, Pfeiffer W, Janssen S, Asnicar F, Sanders JG, et al. (December 2019).

9719: 9702: 8773:"Nitrogenase gene diversity and microbial community structure: a cross-system comparison" 8420:"How to: prophylactic interventions for prevention of Clostridioides difficile infection" 8388: 7870:

Stokes RW, Norris-Jones R, Brooks DE, Beveridge TJ, Doxsee D, Thorson LM (October 2004).

7318: 6297:

Branda SS, Vik S, Friedman L, Kolter R (January 2005). "Biofilms: the matrix revisited".

4328: 4195: 3976:

in an attempt to promote the growth of these naturally occurring bacteria after the 1989

3922: 3732: 3692: 3644: 3524: 3293: 3006: 2963: 2951: 2927: 2462:

Bacteria, as asexual organisms, inherit an identical copy of the parent's genome and are

1794: 1680: 1588: 1554: 1305: 743: 434: 395: 18095: 14700: 14413:. LSU Law Center's Medical and Public Health Law Site, Historic Public Health Articles. 14243: 14047: 13648: 12889: 12842: 12789: 12301:

Lippincott's Illustrated Reviews: Microbiology (Lippincott's Illustrated Reviews Series)

12159: 11987: 11835: 11410: 11380: 11189: 11007: 10803: 10744: 10687: 10591: 10503: 10282: 10173: 10108: 9526: 9337: 9190: 8926: 8909: 8833: 8788: 8677:

Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences

8482: 8308: 8269: 8239: 8188: 7084: 6859: 6600: 6218: 5480: 5242: 5194:

Poole AM, Penny D (January 2007). "Evaluating hypotheses for the origin of eukaryotes".

5116: 5069: 4958: 4756: 4634: 19557: 19354: 19276: 18562: 18244: 17988: 17952: 17940: 17787: 17673: 17603: 17591: 17581: 17535: 17318: 17217: 17026: 16938: 16931: 16724: 15035: 15013: 15001: 14976: 14911: 14204: 14161: 14067: 14033: 13955: 13872: 13855: 13801: 13762: 13608: 13591: 13450: 13437: 13417: 13398: 13262: 13237: 13165: 13140: 13042: 12988: 12963: 12811: 12705: 12653:

Martin MO (September 2002). "Predatory prokaryotes: an emerging research opportunity".

12635: 12587: 12560: 12536: 12511: 12451: 12424: 12349: 12281: 12009: 11944: 11917: 11893: 11866: 11847: 11752: 11725: 11677:"Detection of infection or infectious agents by use of cytologic and histologic stains" 11554: 11509: 11451: 11424: 11206: 11173: 11154: 11104: 11079: 11060: 10912: 10885: 10812: 10785: 10761: 10728: 10704: 10671: 10611: 10520: 10487: 10419: 10244: 10190: 10157: 10138: 9917: 9874: 9825: 9683: 9636: 9624: 9593: 9581: 9546: 9495: 9452: 9301: 9276: 9257: 9150: 9123: 9025: 8890: 8853: 8748: 8721: 8697: 8672: 8653: 8551: 8502: 8400: 8208: 8157: 8114: 8101: 8074: 7998: 7973: 7948: 7923: 7847: 7814: 7795: 7752: 7739: 7722: 7698: 7671: 7595: 7558: 7533: 7514: 7459: 7434: 7245: 7147: 7104: 6973: 6930: 6876: 6843: 6772: 6747: 6723: 6698: 6679: 6630: 6569: 6526: 6483: 6274: 6249: 6098: 6024: 5999: 5980: 5932: 5907: 5777: 5738: 5676: 5562: 5535: 5499: 5464: 5445: 5397: 5371:"Extremophilic Microorganisms for the Treatment of Toxic Pollutants in the Environment" 5370: 5308: 5281: 5262: 5128: 5081: 4978: 4927: 4716: 4689: 4488: 4431: 4396: 4350: 4316: 4281: 4123: 4080: 3669: 3598: 3454: 3358: 3336: 3014: 2842: 2815: 2797: 2754: 2647: 2548: 2490: 2374: 2319: 2092: 2055: 1924: 1850: 1812: 1806: 1675: 1475: 1181: 1026: 903: 787: 438: 171: 125: 14719: 14684: 14501: 14368: 14343: 14260: 14223: 14113: 14086: 13832: 13819:

Liese A, Filho MV (December 1999). "Production of fine chemicals using biocatalysis".

13486: 12487: 12227: 12202: 12178: 12143: 12044: 11800: 11701: 11676: 11292: 11267: 10752: 10463: 10438: 10072: 10047: 10023: 9998: 9771: 9746: 9376: 9209: 9174: 9100: 8977: 8951:"Aging and death in an organism that reproduces by morphologically symmetric division" 8950: 8841: 8582: 7896: 7871: 7626: 7368: 7341: 7292: 7267: 7191: 7166: 6410: 6385: 5821: 5796: 5707: 5334:

Baker-Austin C, Dopson M (April 2007). "Life in acid: pH homeostasis in acidophiles".

5024: 4997: 4869: 4844: 4083:

of entire organisms. This is achievable in some well-studied bacteria, with models of

3699:

Each species of pathogen has a characteristic spectrum of interactions with its human

3529: 3028:. Most bacteria have not been characterised and there are many species that cannot be 1285:, occur across the cell membrane between the cytoplasm and the outside of the cell or 19767: 19703: 19576: 19332: 19248: 19150: 18920: 18354: 17913: 17863: 17756: 17695: 17663: 17625: 17608: 17395: 17258: 17224: 17191: 17048: 17043: 17001: 16948: 16824: 16022: 15045: 15008: 14996: 14986: 14888: 14878: 14859: 14842: 14832: 14815: 14805: 14788: 14778: 14761: 14751: 14724: 14639: 14604: 14599: 14582: 14530:. Department of Microbiology and Molecular Cell Sciences, The University of Memphis. 14505: 14373: 14265: 14196: 14153: 14118: 14059: 14006: 14001: 13991: 13974: 13947: 13912: 13877: 13836: 13805: 13793: 13754: 13703: 13662: 13657: 13632: 13613: 13572: 13490: 13455: 13390: 13385: 13368: 13349: 13308: 13267: 13170: 13121: 13080: 13034: 13029: 13012: 12993: 12944: 12903: 12854: 12850: 12803: 12754: 12746: 12697: 12662: 12639: 12627: 12592: 12541: 12491: 12456: 12405: 12341: 12304: 12285: 12273: 12232: 12183: 12089: 12058: 12053: 12001: 11949: 11898: 11839: 11804: 11757: 11706: 11630: 11589: 11546: 11501: 11456: 11392: 11297: 11248: 11211: 11146: 11109: 11064: 11052: 11042: 11011: 10964: 10917: 10866: 10861: 10836: 10817: 10766: 10709: 10652: 10603: 10560: 10525: 10468: 10454: 10411: 10371: 10336: 10294: 10236: 10195: 10130: 10077: 10028: 9980: 9958: 9921: 9909: 9866: 9861: 9844: 9817: 9812: 9795: 9776: 9762: 9724: 9687: 9675: 9628: 9585: 9538: 9487: 9444: 9390: 9380: 9349: 9306: 9249: 9214: 9155: 9104: 9017: 8982: 8931: 8886: 8857: 8845: 8802: 8797: 8772: 8753: 8702: 8645: 8586: 8543: 8538: 8521: 8494: 8451: 8404: 8392: 8346: 8320: 8251: 8200: 8149: 8118: 8106: 8052: 8047: 8022: 8003: 7953: 7901: 7887: 7852: 7834: 7787: 7744: 7703: 7640: 7630: 7599: 7563: 7506: 7464: 7415: 7373: 7297: 7237: 7196: 7139: 7096: 7049: 7014: 6965: 6922: 6881: 6824: 6777: 6728: 6671: 6622: 6561: 6518: 6475: 6438: 6415: 6366: 6361: 6336: 6314: 6279: 6230: 6175: 6135: 6090: 6029: 5972: 5937: 5886: 5826: 5781: 5769: 5742: 5723:"A centimeter-long bacterium with DNA compartmentalized in membrane-bound organelles" 5668: 5567: 5504: 5437: 5402: 5351: 5313: 5254: 5211: 5132: 5120: 5085: 5056: 5029: 4970: 4919: 4874: 4825: 4798:

DeLong EF, Pace NR (August 2001). "Environmental diversity of bacteria and archaea".

4780: 4775: 4740: 4721: 4658: 4653: 4618: 4492: 4480: 4436: 4418: 4324: 4180: 4068: 4052: 4045: 3992: 3869:

to promote animal growth, where they may be contributing to the rapid development of

3866: 3830:

produce an endotoxin that causes gastroenteritis. Some exotoxins can be converted to

3799: 3619: 3394: 3258: 2835: 2655: 2563:

showing a single flagellum at one end of the cell. Scale bar is 0.5 micrometres long.

2478:. Mutations arise from errors made during the replication of DNA or from exposure to 2466:. However, all bacteria can evolve by selection on changes to their genetic material 2138: 2110: 1630: 1527: 1242:, bacteria usually lack large membrane-bound structures in their cytoplasm such as a 920: 841: 791: 783: 687: 590: 387: 375: 355: 339: 31: 14208: 13930:

Chattopadhyay A, Bhatnagar NB, Bhatnagar R (2004). "Bacterial insecticidal toxins".

13766: 13402: 13046: 12709: 12353: 12013: 11851: 11558: 11513: 10439:"The bacterial flagellum: reversible rotary propellor and type III export apparatus" 10423: 10354:

Davison J (September 1999). "Genetic exchange between bacteria in the environment".

10248: 9829: 9597: 9550: 9499: 9456: 9261: 9029: 8894: 8657: 8624:

Hellingwerf KJ, Crielaard W, Hoff WD, Matthijs HC, Mur LR, van Rotterdam BJ (1994).

8555: 8506: 8161: 7756: 7619:

The Bacterial Flagellar Motor: Structure and Function of a Complex Molecular Machine

7518: 7358: 7249: 7108: 6934: 6634: 6573: 6487: 6226: 6102: 6059:

Claessen D, Rozen DE, Kuipers OP, Søgaard-Andersen L, van Wezel GP (February 2014).

5984: 5812: 5680: 5449: 5266: 4931: 4168:, and his findings were looked at again in the light of the more recent findings of 4160:

of his own design. He then published his observations in a series of letters to the

3750:

able to grow and reproduce only within the cells of other organisms. One species of

2639:, are found between two membranes in the periplasmic space. They have a distinctive 607: 18630: 18509: 18401: 18344: 18284: 18279: 18207: 18192: 17883: 17807: 17741: 17596: 17110: 16986: 16921: 16680: 16438: 16393: 16346: 16184: 15350: 14960: 14802:

Strickberger's Evolution : the integration of genes, organisms and populations

14714: 14704: 14631: 14594: 14497: 14363: 14355: 14255: 14247: 14188: 14165: 14145: 14108: 14098: 14051: 13996: 13986: 13959: 13939: 13904: 13867: 13828: 13785: 13746: 13693: 13652: 13603: 13562: 13482: 13445: 13429: 13380: 13339: 13298: 13257: 13249: 13160: 13152: 13111: 13072: 13060: 13024: 12983: 12975: 12934: 12893: 12846: 12815: 12793: 12736: 12689: 12619: 12582: 12572: 12531: 12523: 12483: 12446: 12436: 12401: 12397: 12333: 12263: 12222: 12218: 12214: 12173: 12163: 12048: 12040: 11991: 11939: 11929: 11888: 11878: 11831: 11796: 11747: 11737: 11696: 11688: 11620: 11581: 11538: 11493: 11446: 11436: 11384: 11287: 11279: 11240: 11201: 11193: 11158: 11142: 11138: 11099: 11091: 11034: 11003: 10956: 10907: 10897: 10856: 10852: 10848: 10807: 10799: 10756: 10748: 10699: 10691: 10642: 10615: 10595: 10552: 10515: 10507: 10458: 10450: 10403: 10363: 10328: 10286: 10226: 10185: 10177: 10142: 10120: 10112: 10067: 10063: 10059: 10018: 10014: 10010: 9948: 9901: 9878: 9856: 9807: 9766: 9758: 9714: 9667: 9640: 9620: 9577: 9530: 9479: 9436: 9372: 9341: 9296: 9288: 9241: 9204: 9194: 9145: 9135: 9096: 9009: 8972: 8962: 8921: 8882: 8837: 8792: 8743: 8733: 8692: 8684: 8637: 8578: 8533: 8486: 8441: 8431: 8384: 8312: 8243: 8212: 8192: 8141: 8096: 8086: 8042: 8038: 8034: 7993: 7985: 7943: 7935: 7891: 7883: 7842: 7826: 7799: 7779: 7734: 7693: 7683: 7622: 7591: 7553: 7545: 7498: 7454: 7446: 7407: 7363: 7353: 7287: 7279: 7227: 7186: 7178: 7151: 7131: 7088: 7004: 6977: 6957: 6912: 6871: 6863: 6816: 6767: 6759: 6718: 6710: 6683: 6661: 6614: 6553: 6530: 6510: 6467: 6405: 6397: 6356: 6352: 6348: 6306: 6269: 6261: 6222: 6167: 6131: 6127: 6080: 6072: 6019: 6011: 5964: 5927: 5919: 5857: 5816: 5808: 5761: 5730: 5703: 5664: 5660: 5557: 5547: 5494: 5484: 5429: 5392: 5382: 5343: 5303: 5293: 5246: 5203: 5167: 5112: 5073: 5019: 5009: 4982: 4962: 4909: 4901: 4864: 4860: 4856: 4817: 4770: 4760: 4711: 4701: 4648: 4638: 4470: 4426: 4408: 4223: 3850: 3314: 3248: 3188: 3153: 3118: 3103: 3010: 2923: 2773: 2592: 2519: 2358: 2307: 2242: 2218: 2174: 1943: 1916: 1858: 1600: 1599:. pilus) are cellular appendages, slightly larger than fimbriae, that can transfer 1448:) is able to kill bacteria by inhibiting a step in the synthesis of peptidoglycan. 1051: 652: 569: 486: 347: 312: 262: 118: 114: 14251: 14071: 13344: 13327: 12029:"The role of DNA amplification technology in the diagnosis of infectious diseases" 10960: 8075:"The Bacillus subtilis endospore: assembly and functions of the multilayered coat" 7283: 7182: 6401: 3818:, which are produced by bacteria and released into the environment. The bacterium 1318:

inside, with arrows highlighting visible carboxysomes. Scale bars indicate 100 nm.

307:: bacterium) are ubiquitous, mostly free-living organisms often consisting of one 19192: 18803: 18708: 18670: 18625: 18557: 18314: 18274: 18259: 18152: 17908: 17792: 17746: 17638: 17336: 17235: 17120: 16996: 16926: 16879: 16731: 16635: 16448: 16443: 16197: 15999: 15977: 15792: 15505: 15476: 15426: 15261: 15156: 15124: 14583:"Of blood, inflammation and gunshot wounds: the history of the control of sepsis" 14359: 13789: 12425:"Commensal Bacteria: An Emerging Player in Defense Against Respiratory Pathogens" 11724:

Tang S, Orsi RH, Luo H, Ge C, Zhang G, Baker RC, Stevenson A, Wiedmann M (2019).

11441: 11033:. Advances in Experimental Medicine and Biology. Vol. 1197. pp. 27–43. 10290: 9953: 9936: 9742: 8967: 8722:"Diazotrophs for Lowering Nitrogen Pollution Crises: Looking Deep Into the Roots" 8316: 5756:

Sanderson K (June 2022). "Largest bacterium ever found is surprisingly complex".

5536:"Molecular Physiology of Anaerobic Phototrophic Purple and Green Sulfur Bacteria" 4544: 4413: 4076: 4072: 3854: 3807: 3803: 3578: 3561: 3496: 3218: 3183: 3168: 3063: 3049: 2990: 2861: 2811: 2777: 2736: 2730: 2346: 2263:

In the laboratory, bacteria are usually grown using solid or liquid media. Solid

2199: 2146: 2118: 2076: Organic compounds (chemoheterotrophs) or carbon fixation (chemoautotrophs) 2047: Organic compounds (lithoheterotrophs) or carbon fixation (lithoautotrophs) 2030: 2014: Organic compounds (photoheterotrophs) or carbon fixation (photoautotrophs) 1959: 1951: 1900: 1704: 1633:. These structures can protect cells from engulfment by eukaryotic cells such as 873: 824: 683: 19718: 14136:

Walsh G (April 2005). "Therapeutic insulins and their large-scale manufacture".

12527: 12368: 12028: 11388: 11038: 10886:"Bacterial Semiochemicals and Transkingdom Interactions with Insects and Plants" 7450: 6867: 5280:

Stephens TG, Gabr A, Calatrava V, Grossman AR, Bhattacharya D (September 2021).

4184:

was a genus that contained non-spore-forming rod-shaped bacteria, as opposed to

3824:

for example, produces a powerful exotoxin that cause respiratory paralysis, and

2522:. Third, bacteria can transfer genetic material through direct cell contact via 2153:

to generate energy and reducing power, secreting metabolic by-products (such as

1831:, a common problem in healthcare settings, is caused by spore-forming bacteria. 101: 19581: 19241: 19206: 19199: 19178: 19157: 19134: 19014: 18863: 18808: 18798: 18640: 18454: 18406: 18319: 18294: 18289: 18269: 18264: 18167: 18157: 18024: 18019: 17978: 17903: 17782: 17717: 17678: 17668: 16991: 16955: 16711: 16650: 16641: 16538: 16494: 16302: 16265: 16179: 16071: 16012: 15515: 15492: 15195: 15108: 15095: 15090: 14991: 14689: