Microbial intelligence

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Microbial intelligence (known as bacterial intelligence) is the intelligence shown by microorganisms. This includes complex adaptive behavior shown by single cells, and altruistic or cooperative behavior in populations of like or unlike cells. It is often mediated by chemical signalling that induces physiological or behavioral changes in cells and influences colony structures. [1]

Contents

Complex cells, like protozoa or algae, show remarkable abilities to organize themselves in changing circumstances. [2] Shell-building by amoebae reveals complex discrimination and manipulative skills that are ordinarily thought to occur only in multicellular organisms.

Even bacteria can display more behavior as a population. These behaviors occur in single species populations, or mixed species populations. Examples are colonies or swarms of myxobacteria, quorum sensing, and biofilms. [1] [3]

It has been suggested that a bacterial colony loosely mimics a biological neural network. The bacteria can take inputs in form of chemical signals, process them and then produce output chemicals to signal other bacteria in the colony.

Bacteria communication and self-organization in the context of network theory has been investigated by Eshel Ben-Jacob research group at Tel Aviv University which developed a fractal model of bacterial colony and identified linguistic and social patterns in colony lifecycle. [4]

Examples of microbial intelligence

Bacterial

Protists

Applications

Bacterial colony optimisation

Bacterial colony optimization is an algorithm used in evolutionary computing. The algorithm is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration.

Slime mold computing

Logical circuits can be built with slime moulds. [17] Distributed systems experiments have used them to approximate motorway graphs. [18] The slime mould Physarum polycephalum is able to solve the Traveling Salesman Problem, a combinatorial test with exponentially increasing complexity, in linear time. [19]

Soil ecology

Microbial community intelligence is found in soil ecosystems in the form of interacting adaptive behaviors and metabolisms. [20] According to Ferreira et al., "Soil microbiota has its own unique capacity to recover from change and to adapt to the present state[...] [This] capacity to recover from change and to adapt to the present state by altruistic, cooperative and co-occurring behavior is considered a key attribute of microbial community intelligence." [21]

Many bacteria that exhibit complex behaviors or coordination are heavily present in soil in the form of biofilms. [1] Micropredators that inhabit soil, including social predatory bacteria, have significant implications for its ecology. Soil biodiversity, managed in part by these micropredators, is of significant importance for carbon cycling and ecosystem functioning. [22]

The complicated interaction of microbes in the soil has been proposed as a potential carbon sink. Bioaugmentation has been suggested as a method to increase the 'intelligence' of microbial communities, that is, adding the genomes of autotrophic, carbon-fixing or nitrogen-fixing bacteria to their metagenome. [20]

Bacterial transformation

Bacterial transformation is a form of microbobial intelligence that involves complex adaptive cooperative behavior. About 80 species of bacteria have so far been identified that are likely capable of transformation, including about equal numbers of Gram-positive and Gram-negative bacteria. [23]

Vibrio cholerae

V. cholerae has the ability to communicate strongly at the cellular level for the purpose of bacterial transformation, and this form of microbial intelligence involves cooperative quorum-sensing. [24] [25] Two different stimuli that are encountered in the small intestine, the absence of oxygen and the presence of host-produced bile salts, stimulate V. cholerae quorum sensing and thus its pathogenicity. [26] Cooperative quorum sensing, involving microbial intelligence, facilitates natural genetic transformation, a process in which extracellular DNA is taken up by (competent) V. cholerae cells. [27] V. cholerae is a bacterial pathogen that causes cholera with severe contagious diarrhea that affects millions of people globally.

Streptococcus pneumoniae

S. pneumoniae uses a cooperative complex quorum sensing system, a form of microbial intelligence, for regulating the release of bacteriocins as well as for differentiating into the competent state necessary for natural genetic transformation. [28] The competent state is induced by a peptide pheromone. [29] The induction of competence results in the release of DNA from a sub-fraction of S. pneumoniae cells in the population, probably by cell lysis. Subsequently the majority of the S. pneumoniae cells that have been induced to competence act as recipients and take up the DNA that is released by the donors. [29] Natural transformation in S. pneumoniae is an adaptive form of microbial intelligence for promoting genetic recombination that appears to be similar to sex in higher organisms. [29] S. pneumoniae is responsible for the death of more than a million people yearly. [30]

See also

Related Research Articles

<span class="mw-page-title-main">Biofilm</span> Aggregation of bacteria or cells on a surface

A biofilm is a syntrophic community of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric combination of extracellular polysaccharides, proteins, lipids and DNA. Because they have a three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes".

<i>Vibrio cholerae</i> Species of bacterium

Vibrio cholerae is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimp, and other shellfish. Some strains of V. cholerae are pathogenic to humans and cause a deadly disease called cholera, which can be derived from the consumption of undercooked or raw marine life species or drinking contaminated water.

In biology, quorum sensing or quorum signaling (QS) is the process of cell-to-cell communication that allows bacteria to detect and respond to cell population density by gene regulation, typically as a means of acclimating to environmental disadvantages.

<i>Vibrio</i> Genus of bacteria and the disease it can cause

Vibrio is a genus of Gram-negative bacteria, possessing a curved-rod (comma) shape, several species of which can cause foodborne infection or soft-tissue infection called Vibriosis. Infection is commonly associated with eating undercooked seafood. Being highly salt tolerant and unable to survive in freshwater, Vibrio spp. are commonly found in various salt water environments. Vibrio spp. are facultative anaerobes that test positive for oxidase and do not form spores. All members of the genus are motile. They are able to have polar or lateral flagellum with or without sheaths. Vibrio species typically possess two chromosomes, which is unusual for bacteria. Each chromosome has a distinct and independent origin of replication, and are conserved together over time in the genus. Recent phylogenies have been constructed based on a suite of genes.

<span class="mw-page-title-main">Secretion</span> Controlled release of substances by cells or tissues

Secretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. In contrast, excretion is the removal of certain substances or waste products from a cell or organism. The classical mechanism of cell secretion is via secretory portals at the plasma membrane called porosomes. Porosomes are permanent cup-shaped lipoprotein structures embedded in the cell membrane, where secretory vesicles transiently dock and fuse to release intra-vesicular contents from the cell.

<i>Aliivibrio fischeri</i> Species of bacterium

Aliivibrio fischeri is a Gram-negative, rod-shaped bacterium found globally in marine environments. This species has bioluminescent properties, and is found predominantly in symbiosis with various marine animals, such as the Hawaiian bobtail squid. It is heterotrophic, oxidase-positive, and motile by means of a single polar flagella. Free-living A. fischeri cells survive on decaying organic matter. The bacterium is a key research organism for examination of microbial bioluminescence, quorum sensing, and bacterial-animal symbiosis. It is named after Bernhard Fischer, a German microbiologist.

A slime layer in bacteria is an easily removable, unorganized layer of extracellular material that surrounds bacteria cells. Specifically, this consists mostly of exopolysaccharides, glycoproteins, and glycolipids. Therefore, the slime layer is considered as a subset of glycocalyx.

<i>Burkholderia cenocepacia</i> Species of bacterium

Burkholderia cenocepacia is a Gram-negative, rod-shaped bacterium that is commonly found in soil and water environments and may also be associated with plants and animals, particularly as a human pathogen. It is one of over 20 species in the Burkholderia cepacia complex (Bcc) and is notable due to its virulence factors and inherent antibiotic resistance that render it a prominent opportunistic pathogen responsible for life-threatening, nosocomial infections in immunocompromised patients, such as those with cystic fibrosis or chronic granulomatous disease. The quorum sensing systems CepIR and CciIR regulate the formation of biofilms and the expression of virulence factors such as siderophores and proteases. Burkholderia cenocepacia may also cause disease in plants, such as in onions and bananas. Additionally, some strains serve as plant growth-promoting rhizobacteria.

In biology, an autoinducer is a signaling molecule that enables detection and response to changes in the population density of bacterial cells. Synthesized when a bacterium reproduces, autoinducers pass outside the bacterium and into the surrounding medium. They are a key component of the phenomenon of quorum sensing: as the density of quorum-sensing bacterial cells increases, so does the concentration of the autoinducer. A bacterium’s detection of an autoinducer above some minimum threshold triggers altered gene expression.

<span class="mw-page-title-main">Prokaryote</span> Unicellular organism lacking a membrane-bound nucleus

A prokaryote is a single-cell organism whose cell lacks a nucleus and other membrane-bound organelles. The word prokaryote comes from the Ancient Greek πρό 'before' and κάρυον 'nut, kernel'. In the two-empire system arising from the work of Édouard Chatton, prokaryotes were classified within the empire Prokaryota. However in the three-domain system, based upon molecular analysis, prokaryotes are divided into two domains: Bacteria and Archaea. Organisms with nuclei are placed in a third domain, Eukaryota.

<span class="mw-page-title-main">Gliding motility</span>

Gliding motility is a type of translocation used by microorganisms that is independent of propulsive structures such as flagella, pili, and fimbriae. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms of this motility are only partially known.

Bacterial small RNAs are small RNAs produced by bacteria; they are 50- to 500-nucleotide non-coding RNA molecules, highly structured and containing several stem-loops. Numerous sRNAs have been identified using both computational analysis and laboratory-based techniques such as Northern blotting, microarrays and RNA-Seq in a number of bacterial species including Escherichia coli, the model pathogen Salmonella, the nitrogen-fixing alphaproteobacterium Sinorhizobium meliloti, marine cyanobacteria, Francisella tularensis, Streptococcus pyogenes, the pathogen Staphylococcus aureus, and the plant pathogen Xanthomonas oryzae pathovar oryzae. Bacterial sRNAs affect how genes are expressed within bacterial cells via interaction with mRNA or protein, and thus can affect a variety of bacterial functions like metabolism, virulence, environmental stress response, and structure.

Microorganisms engage in a wide variety of social interactions, including cooperation. A cooperative behavior is one that benefits an individual other than the one performing the behavior. This article outlines the various forms of cooperative interactions seen in microbial systems, as well as the benefits that might have driven the evolution of these complex behaviors.

Interspecies quorum sensing is a type of quorum sensing in which bacteria send and receive signals to other species besides their own. This is accomplished by the secretion of signaling molecules which trigger a response in nearby bacteria at high enough concentrations. Once the molecule hits a certain concentration it triggers the transcription of certain genes such as virulence factors. It has been discovered that bacteria can not only interact via quorum sensing with members of their own species but that there is a kind of universal molecule that allows them to gather information about other species as well. This universal molecule is called autoinducer 2 or AI-2.

<i>Myxococcus</i> Genus of bacteria

Myxococcus is a genus of bacteria in the family Myxococcaceae. Myxococci are Gram-negative, spore-forming, chemoorganotrophic, obligate aerobes. They are elongated rods with rounded or tapered ends, and they are nonflagellated. The cells move by gliding and can predate other bacteria. The genus has been isolated from soil.

The type VI secretion system (T6SS) is molecular machine used by a wide range of Gram-negative bacterial species to transport effectors from the interior of a bacterial cell across the cellular envelope into an adjacent target cell. While often reported that the T6SS was discovered in 2006 by researchers studying the causative agent of cholera, Vibrio cholerae, the first study demonstrating that T6SS genes encode a protein export apparatus was actually published in 2004, in a study of protein secretion by the fish pathogen Edwardsiella tarda.

Everett Peter Greenberg is an American microbiologist. He is the inaugural Eugene and Martha Nester Professor of Microbiology at the Department of Microbiology of the University of Washington School of Medicine. He is best known for his research on quorum sensing, and has received multiple awards for his work.

<span class="mw-page-title-main">VqmR sRNA</span>

VqmR small RNA was discovered in Vibrio cholerae, a bacterium which can cause cholera, using differential RNA sequencing (sRNA-seq) under conditions of low and high cell density which were being used to study quorum sensing (QS). QS controls virulence and biofilm formation in Vibrio cholerae; it has been shown previously that it is directed by the Qrr sRNAs. VqmR has been shown to repress the expression of multiple mRNAs including the rtx toxin genes and the vpsT, which is required for biofilm formation. In fact, VqmR which is highly conserved in vibrionaceae, was shown to strongly inhibit biofilm formation by repressing the vpsT gene; it could be the link between biofilm formation and QS.

<span class="mw-page-title-main">Competence stimulating peptide</span>

Competence stimulating peptide (CSP), a chemical messenger assisting quorum sensing initiation, exists in many bacterial genera. Bacterial transformation of deoxyribonucleic acids (DNA) is driven by CSP coupled quorum sensing.

References

  1. 1 2 3 Rennie J (13 November 2017). "The Beautiful Intelligence of Bacteria and Other Microbes". Quanta Magazine.
  2. ↑ Ford, Brian J. (2004). "Are Cells Ingenious?" (PDF). Microscope. 52 (3/4): 135–144.
  3. 1 2 3 4 5 Chimileski S, Kolter R (2017). Life at the Edge of Sight: A Photographic Exploration of the Microbial World. Cambridge, Massachusetts: Harvard University Press. ISBN   9780674975910.
  4. ↑ Cohen, Inon, et al. (1999). "Continuous and discrete models of cooperation in complex bacterial colonies" (PDF). Fractals. 7.03 (1999) (3): 235–247. arXiv: cond-mat/9807121 . doi:10.1142/S0218348X99000244. S2CID   15489293. Archived from the original (PDF) on 2014-08-08. Retrieved 2014-12-25.
  5. ↑ Beagle SD, Lockless SW (November 2015). "Microbiology: Electrical signalling goes bacterial". Nature. 527 (7576): 44–5. Bibcode:2015Natur.527...44B. doi: 10.1038/nature15641 . PMID   26503058.
  6. ↑ Muñoz-Dorado J, Marcos-Torres FJ, García-Bravo E, Moraleda-Muñoz A, Pérez J (2016-05-26). "Myxobacteria: Moving, Killing, Feeding, and Surviving Together". Frontiers in Microbiology. 7: 781. doi: 10.3389/fmicb.2016.00781 . PMC   4880591 . PMID   27303375.
  7. ↑ Kaiser D (2013-11-12). "Are Myxobacteria intelligent?". Frontiers in Microbiology. 4: 335. doi: 10.3389/fmicb.2013.00335 . PMC   3824092 . PMID   24273536.
  8. ↑ Islam ST, Vergara Alvarez I, Saïdi F, Guiseppi A, Vinogradov E, Sharma G, et al. (June 2020). "Modulation of bacterial multicellularity via spatio-specific polysaccharide secretion". PLOS Biology. 18 (6): e3000728. doi: 10.1371/journal.pbio.3000728 . PMC   7310880 . PMID   32516311.
  9. ↑ Escalante A. "Scientists Just Brought Us One Step Closer To A Living Computer". Forbes. Retrieved 18 May 2020.
  10. ↑ "They remember: Communities of microbes found to have working memory". phys.org. Retrieved 18 May 2020.
  11. ↑ Yang CY, Bialecka-Fornal M, Weatherwax C, Larkin JW, Prindle A, Liu J, et al. (May 2020). "Encoding Membrane-Potential-Based Memory within a Microbial Community". Cell Systems. 10 (5): 417–423.e3. doi:10.1016/j.cels.2020.04.002. PMC   7286314 . PMID   32343961.
  12. ↑ "The 'sultan of slime': Biologist continues to be fascinated by organisms after nearly 70 years of study". Princeton University. Retrieved 2019-12-06.
  13. ↑ "Can a single-celled organism 'change its mind'? New study says yes". phys.org. Retrieved 2019-12-06.
  14. ↑ Tang SKY; Marshall, W. F. (22 October 2018). "Cell learning". Current Biology. 28 (20): R1180–R1184. Bibcode:2018CBio...28R1180T. doi: 10.1016/j.cub.2018.09.015 . PMC   9673188 . PMID   30352182. S2CID   53031600.
  15. ↑ Alipour A, Dorvash M, Yeganeh Y, Hatam G (2017-11-29). "Paramecium Learning: New Insights and Modifications". bioRxiv: 225250. doi: 10.1101/225250 .
  16. ↑ Kunita I, Yamaguchi T, Tero A, Akiyama M, Kuroda S, Nakagaki T (May 2016). "A ciliate memorizes the geometry of a swimming arena". Journal of the Royal Society, Interface. 13 (118): 20160155. doi:10.1098/rsif.2016.0155. PMC   4892268 . PMID   27226383.
  17. ↑ "Computing with slime: Logical circuits built using living slime molds". ScienceDaily. Retrieved 2019-12-06.
  18. ↑ Adamatzky A, Akl S, Alonso-Sanz R, Van Dessel W, Ibrahim Z, Ilachinski A, et al. (2013-06-01). "Are motorways rational from slime mould's point of view?". International Journal of Parallel, Emergent and Distributed Systems. 28 (3): 230–248. arXiv: 1203.2851 . doi:10.1080/17445760.2012.685884. ISSN   1744-5760. S2CID   15534238.
  19. ↑ "Slime Mold Can Solve Exponentially Complicated Problems in Linear Time | Biology, Computer Science | Sci-News.com". Breaking Science News | Sci-News.com. Retrieved 2019-12-06.
  20. 1 2 Agarwal L, Qureshi A, Kalia VC, Kapley A, Purohit HJ, Singh RN (2014-05-25). "Arid ecosystem: Future option for carbon sinks using microbial community intelligence". Current Science. 106 (10): 1357–1363. JSTOR   24102481.
  21. ↑ Ferreira C, Kalantari Z, Salvati L, Canfora L, Zambon I, Walsh R (2019-01-01). "Chapter 6: Urban Areas". Soil Degradation, Restoration and Management in a Global Change Context. Advances in Chemical Pollution Environmental Management and Protection. Vol. 4. p. 232. ISBN   978-0-12-816415-0 . Retrieved 2020-01-05.
  22. ↑ Zhang L, Lueders T (September 2017). "Micropredator niche differentiation between bulk soil and rhizosphere of an agricultural soil depends on bacterial prey". FEMS Microbiology Ecology. 93 (9). doi: 10.1093/femsec/fix103 . PMID   28922803.
  23. ↑ Johnston C, Martin B, Fichant G, Polard P, Claverys JP (March 2014). "Bacterial transformation: distribution, shared mechanisms and divergent control". Nat Rev Microbiol. 12 (3): 181–96. doi:10.1038/nrmicro3199. PMID   24509783.
  24. ↑ Sajeevan A, Ramamurthy T, Solomon AP (March 2024). "Vibrio cholerae virulence and its suppression through the quorum-sensing system". Crit Rev Microbiol: 1–22. doi:10.1080/1040841X.2024.2320823. PMID   38441045.
  25. ↑ Li Y, Yan J, Li J, Xue X, Wang Y, Cao B (December 2023). "A novel quorum sensing regulator LuxT contributes to the virulence of Vibrio cholerae". Virulence. 14 (1): 2274640. doi:10.1080/21505594.2023.2274640. PMC   10621291 . PMID   37908129.
  26. ↑ Mashruwala AA, Bassler BL (July 2020). "The Vibrio cholerae Quorum-Sensing Protein VqmA Integrates Cell Density, Environmental, and Host-Derived Cues into the Control of Virulence". mBio. 11 (4). doi:10.1128/mBio.01572-20. PMC   7387800 . PMID   32723922.
  27. ↑ Blokesch M (September 2012). "A quorum sensing-mediated switch contributes to natural transformation of Vibrio cholerae". Mob Genet Elements. 2 (5): 224–227. doi:10.4161/mge.22284. PMC   3575429 . PMID   23446800.
  28. ↑ Shanker E, Federle MJ (January 2017). "Quorum Sensing Regulation of Competence and Bacteriocins in Streptococcus pneumoniae and mutans". Genes (Basel). 8 (1): 15. doi: 10.3390/genes8010015 . PMC   5295010 . PMID   28067778.
  29. 1 2 3 Steinmoen H, Knutsen E, Håvarstein LS (May 2002). "Induction of natural competence in Streptococcus pneumoniae triggers lysis and DNA release from a subfraction of the cell population". Proc Natl Acad Sci U S A. 99 (11): 7681–6. doi: 10.1073/pnas.112464599 . PMC   124321 . PMID   12032343.
  30. ↑ Junges R, Salvadori G, Shekhar S, Åmdal HA, Periselneris JN, Chen T, Brown JS, Petersen FC (2017). "A Quorum-Sensing System That Regulates Streptococcus pneumoniae Biofilm Formation and Surface Polysaccharide Production". mSphere. 2 (5). doi:10.1128/mSphere.00324-17. PMC   5597970 . PMID   28932816.

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