{{Short description|Species of bacteria}} thumb|''A. baylyi'' under 10x ocular lens and 100x objective lens with crystal violet stain. {{Speciesbox | image = | image_caption = | taxon = Acinetobacter baylyi | authority = Carr ''et al.'' 2003 }}
'''''Acinetobacter baylyi''''' is a bacterial species of the genus ''Acinetobacter''. The species designation was given after the characterization of strains isolated from activated sludge in Victoria, Australia, in 2003.<ref name="auto">{{Cite journal |last1=Carr |first1=Emma L. |last2=Kämpfer |first2=Peter |last3=Patel |first3=Bharat K. C. |last4=Gürtler |first4=Volker |last5=Seviour |first5=Robert J. |date=April 9, 2003 |title=Seven novel species of Acinetobacter isolated from activated sludge |journal=International Journal of Systematic and Evolutionary Microbiology |volume=53 |issue=4 |pages=953–963 |doi=10.1099/ijs.0.02486-0 |pmid=12892111 |doi-access=free}}</ref> ''A. baylyi'' is named after the late Dr. Ronald Bayly, an Australian microbiologist who contributed significantly to research on aromatic compound catabolism in diverse bacteria. The new species designation, in 2003, was found to apply to an already well-studied ''Acinetobacter'' strain known as ADP1 (previously known as BD413), a derivative of a soil isolate characterized in 1969.<ref name=":1">{{Cite journal |last1=Vaneechoutte |first1=Mario |last2=Young |first2=David M. |last3=Ornston |first3=L. Nicholas |last4=De Baere |first4=Thierry |last5=Nemec |first5=Alexandr |last6=Van Der Reijden |first6=Tanny |last7=Carr |first7=Emma |last8=Tjernberg |first8=Ingela |last9=Dijkshoorn |first9=Lenie |date=January 2006 |title=Naturally Transformable Acinetobacter sp. Strain ADP1 Belongs to the Newly Described Species Acinetobacter baylyi |journal=Applied and Environmental Microbiology |language=en |volume=72 |issue=1 |pages=932–936 |bibcode=2006ApEnM..72..932V |doi=10.1128/AEM.72.1.932-936.2006 |issn=0099-2240 |pmc=1352221 |pmid=16391138}}</ref> For a long time, the taxonomy of ''Acinetobacter'' species was complicated by the lack of distinguishing traits. Strain ADP1 was long classified as ''Acinetobacter calcoaceticus'' and it was later referred to without a species name (''Acinetobacter sp.'') Research, particularly in the field of genetics and aromatic compound catabolism, established ''A. baylyi'' as a model organism.<ref>{{Cite journal |last=Juni |first=Elliot |date=November 1972 |title=Interspecies Transformation of Acinetobacter: Genetic Evidence for a Ubiquitous Genus |journal=Journal of Bacteriology |language=en |volume=112 |issue=2 |pages=917–931 |doi=10.1128/jb.112.2.917-931.1972 |pmid=4563985 |pmc=251504 |issn=0021-9193}}</ref><ref name=":4">{{Cite journal |last1=Young |first1=David M. |last2=Parke |first2=Donna |last3=Ornston |first3=L. Nicholas |date=2005-10-01 |title=Opportunities for Genetic Investigation Afforded by ''Acinetobacter baylyi'', A Nutritionally Versatile Bacterial Species That Is Highly Competent for Natural Transformation |journal=Annual Review of Microbiology |volume=59 |issue=1 |pages=519–551 |doi=10.1146/annurev.micro.59.051905.105823 |pmid=16153178 |issn=0066-4227}}</ref>
''Acinetobacter baylyi'' is a nonmotile, gram-negative coccobacillus. It grows under strictly aerobic conditions, is catalase-positive, nitrate-negative, oxidase-negative, and non-fermentative.<ref name=":112">{{Cite web |date=2020-02-01 |title=Acinetobacter baylyi Biofilm Formation Dependent Genes |url=https://microbiologyjournal.org/acinetobacter-baylyi-biofilm-formation-dependent-genes/ |access-date=2024-02-15 |website=Journal of Pure and Applied Microbiology |language=en-US}}</ref><ref>{{Cite journal |last=Talaiekhozani |first=Amirreza |date=2013 |title=Guidelines for Quick Application of Biochemical Tests to Identify Unknown Bacteria |url=https://www.ssrn.com/abstract=4101035 |journal=SSRN Electronic Journal |language=en |doi=10.2139/ssrn.4101035 |issn=1556-5068|url-access=subscription }}</ref> The species is naturally competent, meaning the bacteria can take up exogenous DNA from their surroundings. If there is sufficient sequence identity between the transforming DNA and the genome of the recipient, the foreign DNA will be integrated in the chromosome by allelic replacement.<ref name=":02">{{Cite journal |last1=Elliott |first1=Kathryn T. |last2=Neidle |first2=Ellen L. |date=April 9, 2011 |title=Acinetobacter baylyi ADP1: Transforming the choice of model organism |journal=IUBMB Life |volume=63 |issue=12 |pages=1075–1080 |doi=10.1002/iub.530 |pmid=22034222 |doi-access=free}}</ref> The processes of natural transformation and homologous recombination are incredibly efficient in ''A. baylyi'' compared to all studied microbes, thus contributing to its experimental utility.<ref>{{Citation |last1=Bedore |first1=Stacy R. |title=Natural transformation as a tool in Acinetobacter baylyi: Streamlined engineering and mutational analysis |date=2023 |work=Genome Engineering |pages=207–234 |publisher=Elsevier |doi=10.1016/bs.mim.2023.01.002 |isbn=978-0-12-823540-9 |hdl=10261/350462 |last2=Neidle |first2=Ellen L. |last3=Pardo |first3=Isabel |last4=Luo |first4=Jin |last5=Baugh |first5=Alyssa C. |last6=Duscent-Maitland |first6=Chantel V. |last7=Tumen-Velasquez |first7=Melissa P. |last8=Santala |first8=Ville |last9=Santala |first9=Suvi |hdl-access=free}}</ref> There are numerous biotechnology applications for ''A. baylyi,'' such as producing alternative fuel sources and chemicals, acting as a host for biosensors to monitor the presence of important compounds, and aiding in degradation of pollutants.<ref name=":12">{{Cite journal |last1=Santala |first1=Suvi |last2=Efimova |first2=Elena |last3=Kivinen |first3=Virpi |last4=Larjo |first4=Antti |last5=Aho |first5=Tommi |last6=Karp |first6=Matti |last7=Santala |first7=Ville |date=2011 |title=Improved Triacylglycerol Production in Acinetobacter baylyi ADP1 by Metabolic Engineering |journal=Microbial Cell Factories |language=en |volume=10 |issue=1 |page=36 |doi=10.1186/1475-2859-10-36 |issn=1475-2859 |pmc=3112387 |pmid=21592360 |doi-access=free}}</ref><ref name=":133">{{Cite journal |last1=Luo |first1=Jin |last2=Lehtinen |first2=Tapio |last3=Efimova |first3=Elena |last4=Santala |first4=Ville |last5=Santala |first5=Suvi |date=2019-03-11 |title=Synthetic metabolic pathway for the production of 1-alkenes from lignin-derived molecules |journal=Microbial Cell Factories |volume=18 |issue=1 |page=48 |doi=10.1186/s12934-019-1097-x |issn=1475-2859 |pmc=6410514 |pmid=30857542 |doi-access=free}}</ref><ref name=":142">{{Cite book |last1=Gutnick |first1=David L. |title=Acinetobacter molecular microbiology |last2=Bach |first2=Horacio |date=2008 |publisher=Caister Academic Press |isbn=978-1-904455-20-2 |editor-last=Gerischer |editor-first=Ulrike |location=Norfolk, UK |pages=241–253 |oclc=154685348}}</ref>
== Genetics == One major characteristic of ''A. baylyi'' is its ability to take in free DNA from the environment by natural transformation. A mechanism that incorporates exogenous DNA into its genome.<ref name=":02"/> The genome of ''A. baylyi'' has been completely sequenced, and roughly 35% of ''A. baylyi''<nowiki/>'s genome sequence encodes proteins that contribute to transformation and recombination .<ref>{{Cite book |last1=Gutnick |first1=David L. |title=Acinetobacter molecular microbiology |last2=Bach |first2=Horacio |date=2008 |publisher=Caister Academic Press |isbn=978-1-904455-20-2 |editor-last=Gerischer |editor-first=Ulrike |location=Norfolk, UK |page=232 |oclc=154685348}}</ref> If there are complementary sequences upstream and downstream of the exogenous DNA, ''A. baylyi'' can perform recombination. This mechanism strongly depends on ''A.'' ''baylyi's'' DNA strand break-repair system to ensure success of DNA sequence exchange.<ref>{{Cite journal |last1=Hülter |first1=Nils |last2=Sørum |first2=Vidar |last3=Borch-Pedersen |first3=Kristina |last4=Liljegren |first4=Mikkel M. |last5=Utnes |first5=Ane L. G. |last6=Primicerio |first6=Raul |last7=Harms |first7=Klaus |last8=Johnsen |first8=Pål J. |date=2017-02-15 |title=Costs and benefits of natural transformation in Acinetobacter baylyi |journal=BMC Microbiology |language=en |volume=17 |issue=1 |page=34 |doi=10.1186/s12866-017-0953-2 |doi-access=free |issn=1471-2180 |pmc=5312590 |pmid=28202049}}</ref> The capability of ''A. baylyi'' to take in DNA from the environment may have evolved because it provides benefits for survival.<ref name=":10">{{Cite journal |last1=Utnes |first1=Ane L G |last2=Sørum |first2=Vidar |last3=Hülter |first3=Nils |last4=Primicerio |first4=Raul |last5=Hegstad |first5=Joachim |last6=Kloos |first6=Julia |last7=Nielsen |first7=Kaare M |last8=Johnsen |first8=Pål J |date=2015-10-01 |title=Growth phase-specific evolutionary benefits of natural transformation in Acinetobacter baylyi |journal=The ISME Journal |language=en |volume=9 |issue=10 |pages=2221–2231 |doi=10.1038/ismej.2015.35 |pmid=25848876 |pmc=4579475 |bibcode=2015ISMEJ...9.2221U |issn=1751-7362}}</ref> This also makes ''A. baylyi'' an ideal microbe for laboratory experiments.<ref name=":02"/> Multiple single-gene deletion mutations on dispensable genes of the ADP1 strain have been collected. With the knowledge of the entire genome sequence and the mutants, scientists are able to predict how the ADP1 strain will function in different situations, which expands the capability of the strain for industrial and environmental applications.<ref>{{Cite journal |last1=de Berardinis |first1=Véronique |last2=Vallenet |first2=David |last3=Castelli |first3=Vanina |last4=Besnard |first4=Marielle |last5=Pinet |first5=Agnès |last6=Cruaud |first6=Corinne |last7=Samair |first7=Sumitta |last8=Lechaplais |first8=Christophe |last9=Gyapay |first9=Gabor |last10=Richez |first10=Céline |last11=Durot |first11=Maxime |last12=Kreimeyer |first12=Annett |last13=Le Fèvre |first13=François |last14=Schächter |first14=Vincent |last15=Pezo |first15=Valérie |date=2008 |title=A complete collection of single-gene deletion mutants of Acinetobacter baylyi ADP1 |journal=Molecular Systems Biology |volume=4 |page=174 |doi=10.1038/msb.2008.10 |issn=1744-4292 |pmc=2290942 |pmid=18319726}}</ref>
''A. baylyi,'' like other organisms, can undergo gene duplication and amplification (GDA) mutations. These GDA mutations, which are a form of spontaneous mutations that result in gene copies in the genome, are important for major processes such as evolution, disease, cancer, and antibiotic resistance. However, this type of mutation is difficult to study. The natural transformation system of ''A. baylyi'' provides a unique method for studying GDA mutations, making it a model system for understanding this type of genetic process.<ref>{{cite journal |last1=Reams |first1=Andrew B |last2=Neidle |first2=Ellen L |title=Gene amplification involves site-specific short homology-independent illegitimate recombination in Acinetobacter sp. strain ADP1 |journal=Journal of Molecular Biology |date=7 May 2004 |volume=338 |issue=4 |pages=643–656 |doi=10.1016/j.jmb.2004.03.031 |pmid=15099734 |url=https://www.sciencedirect.com/science/article/pii/S0022283604003262|url-access=subscription }}</ref><ref>{{cite journal |last1=Seaton |first1=Sarah C |last2=Elliott |first2=Kathryn T |last3=Cuff |first3=Laura E |last4=Laniohan |first4=Nicole S |last5=Patel |first5=Poonam R |last6=Niedle |first6=Ellen L |title=Genome-wide selection for increased copy number in Acinetobacter baylyi ADP1: locus and context-dependent variation in gene amplification |journal=Molecular Microbiology |date=29 December 2011 |volume=83 |issue=3 |pages=520–535 |doi=10.1111/j.1365-2958.2011.07945.x |pmid=22211470 |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2958.2011.07945.x}}</ref><ref>{{Cite journal |last1=Ezezika |first1=Obidimma C. |last2=Collier-Hyams |first2=Lauren S. |last3=Dale |first3=Haley A. |last4=Burk |first4=Andrew C. |last5=Neidle |first5=Ellen L. |date=March 2006 |title=CatM Regulation of the ''benABCDE'' Operon: Functional Divergence of Two LysR-Type Paralogs in ''Acinetobacter baylyi'' ADP1 |journal=Applied and Environmental Microbiology |volume=72 |issue=3 |pages=1749–1758 |doi=10.1128/aem.72.3.1749-1758.2006 |pmid=16517618 |issn=0099-2240|pmc=1393229 |bibcode=2006ApEnM..72.1749E }}</ref>
=== Horizontal gene transfer and cell surface structure === ''A. baylyi'' is a non-motile bacterium that does not have flagella. However, these bacteria possess a type IV pili (T4P) that aid in several cellular functions, such as protein secretions, surface sensing, and horizontal gene transfer (HGT). The T4P of ''A. baylyi'' has been studied in recent literature, and has been said to depend on the PilB and TfpB motors.<ref>{{Cite journal |last1=Ellison |first1=Courtney K. |last2=Dalia |first2=Triana N. |last3=Klancher |first3=Catherine A. |last4=Shaevitz |first4=Joshua W. |last5=Gitai |first5=Zemer |last6=Dalia |first6=Ankur B. |title=Acinetobacter baylyi regulates type IV pilus synthesis by employing two extension motors and a motor protein inhibitor |journal=Nature Communications |date=2021 |volume=12 |issue=1 |article-number=3744 |doi=10.1038/s41467-021-24124-6 |pmid=34145281 |pmc=8213720 |bibcode=2021NatCo..12.3744E |biorxiv=10.1101/2020.09.28.317149 }}</ref>
Additionally'', A. baylyi's'' ability to perform HGT may be aided by the presences of outer membrane vesicles (OMVs). OMVs are produced via vesiculation, which is the bulging of the outer membrane followed by the constriction and release of small, spherical structures from the bacterium. These vesicles are composed of various periplasmic components, including proteins, lipids, and genetic information. OMVs play a significant role in intracellular communication, virulence/bacterial defenses, and adaptations to environmental changes. OMVs released by ''A. baylyi'' offer a type of gene transfer that is not susceptible to degradation by nucleases. However, environmental stressors can impact the efficiency of these OMVs, including the amount of vesicles released, genetic content, and HGT abilities.<ref>{{Cite journal |last1=Fulsundar |first1=Shweta |last2=Harms |first2=Klaus |last3=Flaten |first3=Gøril E. |last4=Johnsen |first4=Pål J. |last5=Chopade |first5=Balu Ananda |last6=Nielsen |first6=Kaare M. |date=June 2014 |editor-last=Kivisaar |editor-first=M. |title=Gene Transfer Potential of Outer Membrane Vesicles of Acinetobacter baylyi and Effects of Stress on Vesiculation |journal=Applied and Environmental Microbiology |language=en |volume=80 |issue=11 |pages=3469–3483 |doi=10.1128/AEM.04248-13 |issn=0099-2240 |pmc=4018862 |pmid=24657872|bibcode=2014ApEnM..80.3469F }}</ref>
''A. baylyi'' strains have also been associated with bacterial adhesion and biofilm formation.<ref name=":3">{{Cite journal |last1=Vallenet |first1=David |last2=Nordmann |first2=Patrice |last3=Barbe |first3=Valérie |last4=Poirel |first4=Laurent |last5=Mangenot |first5=Sophie |last6=Bataille |first6=Elodie |last7=Dossat |first7=Carole |last8=Gas |first8=Shahinaz |last9=Kreimeyer |first9=Annett |last10=Lenoble |first10=Patricia |last11=Oztas |first11=Sophie |last12=Poulain |first12=Julie |last13=Segurens |first13=Béatrice |last14=Robert |first14=Catherine |last15=Abergel |first15=Chantal |date=2008-03-19 |title=Comparative Analysis of Acinetobacters: Three Genomes for Three Lifestyles |journal=PLOS ONE |language=en |volume=3 |issue=3 |article-number=e1805 |bibcode=2008PLoSO...3.1805V |doi=10.1371/journal.pone.0001805 |issn=1932-6203 |pmc=2265553 |pmid=18350144 |doi-access=free}}</ref> Biofilms arise from the aggregation of surface microbial cells enveloped within a matrix of extracellular polymeric substances.<ref>{{Cite journal |last1=Lopez |first1=D. |last2=Vlamakis |first2=H. |last3=Kolter |first3=R. |date=2010-07-01 |title=Biofilms |journal=Cold Spring Harbor Perspectives in Biology |language=en |volume=2 |issue=7 |article-number=a000398 |doi=10.1101/cshperspect.a000398 |issn=1943-0264 |pmc=2890205 |pmid=20519345}}</ref> The biofilms of ''Acinetobacter'' species can range in adhesion strength and thickness. ''Acinetobacter baumannii'' is the species most commonly associated with infectious diseases, including cystic fibrosis and urinary tract infections, due to their ability to adhere to medical devices composed of plastic or glass. It has been found that fimbrial-biogenesis genes and putative surface proteins may be significant to biofilm formation within the ''Acinetobacter'' species.<ref name=":112"/>
== Metabolism == ''A. baylyi'' has been used to study many biochemical pathways, since it is metabolically versatile, it grows rapidly, and is easily cultured.<ref name=":02"/> ''A. baylyi'' can be cultured in media containing diverse carbon sources such as succinate, pyruvate, acetate, ethanol, and many aromatic compounds.<ref name=":2">{{Cite journal |last1=Salcedo-Vite |first1=Karina |last2=Sigala |first2=Juan-Carlos |last3=Segura |first3=Daniel |last4=Gosset |first4=Guillermo |last5=Martinez |first5=Alfredo |date=2019-08-01 |title=Acinetobacter baylyi ADP1 growth performance and lipid accumulation on different carbon sources |url=http://link.springer.com/10.1007/s00253-019-09910-z |journal=Applied Microbiology and Biotechnology |language=en |volume=103 |issue=15 |pages=6217–6229 |doi=10.1007/s00253-019-09910-z |pmid=31144015 |issn=0175-7598|url-access=subscription }}</ref> ''A. baylyi'' is omnipresent in nature and is found in a wide variety of terrestrial and aqueous environments.<ref name="auto" /> Organic growth substrates are oxidized to compounds that can enter the citric acid cycle, also known as the tricarboxylic acid (TCA) cycle. ''A. baylyi''<nowiki/>'s genome was sequenced and its genes annotated to further describe its metabolic properties, aiding its ability to act as a model for metabolic studies.<ref>{{Cite journal |last=de Berardinis |first=Véronique |last2=Durot |first2=Maxime |last3=Weissenbach |first3=Jean |last4=Salanoubat |first4=Marcel |date=2009-10-01 |title=Acinetobacter baylyi ADP1 as a model for metabolic system biology |url=https://linkinghub.elsevier.com/retrieve/pii/S1369527409000940 |journal=Current Opinion in Microbiology |series=Antimicrobials ● Genomics |volume=12 |issue=5 |pages=568–576 |doi=10.1016/j.mib.2009.07.005 |issn=1369-5274|url-access=subscription }}</ref>
''A. baylyi'' has long been a model organism for studying the microbial consumption of these compounds. Aromatic compounds are catabolized through the β-ketoadipate pathway, a pathway by which many different aromatic compounds are converted into either catechol or protocatechuate, which serve as substrates for an aromatic ring-opening dioxygenase. Parallel multi-step pathways yield succinyl-CoA and acetyl-CoA after the ring cleavage of catechol or protocatechuate.<ref name=":8">{{Cite journal |last1=Stuani |first1=Lucille |last2=Lechaplais |first2=Christophe |last3=Salminen |first3=Aaro V. |last4=Ségurens |first4=Béatrice |last5=Durot |first5=Maxime |last6=Castelli |first6=Vanina |last7=Pinet |first7=Agnès |last8=Labadie |first8=Karine |last9=Cruveiller |first9=Stéphane |last10=Weissenbach |first10=Jean |last11=de Berardinis |first11=Véronique |last12=Salanoubat |first12=Marcel |last13=Perret |first13=Alain |date=December 2014 |title=Novel metabolic features in Acinetobacter baylyi ADP1 revealed by a multiomics approach |journal=Metabolomics |language=en |volume=10 |issue=6 |pages=1223–1238 |doi=10.1007/s11306-014-0662-x |issn=1573-3882 |pmc=4213383 |pmid=25374488}}</ref><ref>{{Cite book |last1=Williams |first1=Peter A. |title=Acinetobacter molecular microbiology |last2=Kay |first2=Catherine M. |date=2008 |publisher=Caister Academic Press |isbn=978-1-904455-20-2 |editor-last=Gerischer |editor-first=Ulrike |location=Norfolk, UK |page=99 |language=EN |oclc=154685348}}</ref>
The bacterium lacks a sugar phosphotransferase system (PTS) for glucose uptake and phosphorylation, and pyruvate kinase, a vital enzyme in glycolysis that produces pyruvate from phosphoenolpyruvate.<ref name=":8" /><ref name=":7">{{Cite journal |last1=Kannisto |first1=Matti |last2=Aho |first2=Tommi |last3=Karp |first3=Matti |last4=Santala |first4=Ville |date=2014-11-15 |editor-last=Liu |editor-first=S.-J. |title=Metabolic Engineering of Acinetobacter baylyi ADP1 for Improved Growth on Gluconate and Glucose |journal=Applied and Environmental Microbiology |language=en |volume=80 |issue=22 |pages=7021–7027 |bibcode=2014ApEnM..80.7021K |doi=10.1128/AEM.01837-14 |issn=0099-2240 |pmc=4249021 |pmid=25192990}}</ref><ref name=":2" /><ref name=":9">{{Cite journal |last1=Calil Brondani |first1=Juliana |last2=Afful |first2=Derrick |last3=Nune |first3=Hanna |last4=Hart |first4=Jesse |last5=Cook |first5=Shelby |last6=Momany |first6=Cory |date=June 2023 |title=Overproduction, purification, and transcriptional activity of recombinant Acinetobacter baylyi ADP1 RNA polymerase holoenzyme |url=https://linkinghub.elsevier.com/retrieve/pii/S1046592823000256 |journal=Protein Expression and Purification |language=en |volume=206 |article-number=106254 |doi=10.1016/j.pep.2023.106254 |pmid=36804950|url-access=subscription }}</ref> When glucose is readily available, ''A. baylyi'' can metabolize glucose by first oxidizing it into gluconate, which then enters the Entner-Doudoroff pathway. Without pyruvate kinase, ''A. baylyi'' can produces pyruvate from the cleavage of 2-keto-3-deoxy-6-phosphogluconate. Additional pyruvate is produced from the enzymatic conversion of phosphoenolpyruvate to oxalacetate, then malate, and then pyruvate.<ref name=":7" />
Unlike other bacteria that can predominantly use L-amino acids, ''A. baylyi'' is able to use D-aspartate, as well as L-aspartate, as both a primary carbon and nitrogen source, thus leading scientists to study how D-enantiomers can be used for bacterial growth.<ref>{{Cite journal |last1=Bedore |first1=Stacy R. |last2=Schmidt |first2=Alicia L. |last3=Slarks |first3=Lauren E. |last4=Duscent-Maitland |first4=Chantel V. |last5=Elliott |first5=Kathryn T. |last6=Andresen |first6=Silke |last7=Costa |first7=Flavia G. |last8=Weerth |first8=R. Sophia |last9=Tumen-Velasquez |first9=Melissa P. |last10=Nilsen |first10=Lindsey N. |last11=Dean |first11=Cassandra E. |last12=Karls |first12=Anna C. |last13=Hoover |first13=Timothy R. |last14=Neidle |first14=Ellen L. |date=2022-08-09 |editor-last=Alexandre |editor-first=Gladys |title=Regulation of l - and d -Aspartate Transport and Metabolism in Acinetobacter baylyi ADP1 |journal=Applied and Environmental Microbiology |language=en |volume=88 |issue=15 |pages=e0088322 |doi=10.1128/aem.00883-22 |issn=0099-2240 |pmc=9361831 |pmid=35862682|bibcode=2022ApEnM..88E.883B }}</ref>
''A. baylyi'' uses intracellular arginine to produce a biodegradable alternative to petroleum-based plastics known as polyaspartic acid. ''A. baylyi'' uses arginine to first produce cyanophycin polypeptides, a transient source of nitrogen, which can then be converted to polyaspartic acid.<ref name=":02"/><ref name=":5">{{Cite book |last1=Gutnick |first1=David L. |title=Acinetobacter molecular microbiology |last2=Bach |first2=Horacio |date=2008 |publisher=Caister Academic Press |isbn=978-1-904455-20-2 |editor-last=Gerischer |editor-first=Ulrike |location=Norfolk, UK |page=252 |oclc=154685348}}</ref> Cyanophycin is predominantly formed when nitrogen sources are low, and nitrogen is released by cyanophycinase when environmental nitrogen is limited.<ref name=":5" />
== Applications == ''Acinetobacter baylyi'', a highly adaptable soil-based microbe isolated from diverse environments such as oil-contaminated soils, river waters, activated sludge, and lignocellulosic biomass. It can survive in polluted environments, degrade aromatic compounds and aliphatic substrates, perform horizontal gene transfer (HGT), and undergo genetic modification has made it a versatile tool in environmental remediation, biotechnology, and synthetic biology.<ref name="auto" />
''A. baylyi'' is a model organism in biotechnology due to its natural competency for DNA transformation and its ability to produce value-added compounds. For example, this bacterium demonstrates potential for lignin bioconversion, converting this challenging plant polymer into valuable biofuels and bioproducts, contributing to sustainable resource utilization. Useful compounds that can be produced by A. baylyi include triacylglycerols (TAGs) and wax esters, compounds essential for industries like cosmetics, oleochemicals, and biofuels. Genetic modifications enhance its efficiency in nitrogen-rich environments, redirecting carbon flow to produce TAGs and wax esters.<ref name=":4" />
Another compound produced by ''A. baylyi'' that has commercial value is emulsan, a biosurfactant effective at mixing with hydrophobic substances such as oil. Emulsan reduces oil viscosity, aiding transport and degradation processes, and has applications in cleaning and industrial oil management. Its non-toxic properties make it an ideal alternative to synthetic surfactants for environmental remediating oil spills and addressing other forms of environmental contamination.<ref name=":1" />
''A. baylyi'' has been developed as a sophisticated detector of tumor DNA. It has been used as a biosensor for DNA sequences and mutations. ''A. baylyi'' can integrate DNA characteristic of colorectal cancer (CRC) cells and tumors. ''A. baylyi'' was engineered using CRISPR-discriminated horizontal gene transfer (CATCH). This innovative application does not require donor cassettes for detection and offers a modular framework for targeting specific DNA sequences, including oncogenic mutations. The biosensors hold potential for non-invasive diagnostics, providing a viable alternative to invasive procedures like colonoscopies.<ref>{{Cite journal |last1=Cooper |first1=Robert M. |last2=Wright |first2=Josephine A. |last3=Ng |first3=Jia Q. |last4=Goyne |first4=Jarrad M. |last5=Suzuki |first5=Nobumi |last6=Lee |first6=Young K. |last7=Ichinose |first7=Mari |last8=Radford |first8=Georgette |last9=Ryan |first9=Feargal J. |last10=Kumar |first10=Shalni |last11=Thomas |first11=Elaine M. |last12=Vrbanac |first12=Laura |last13=Knight |first13=Rob |last14=Woods |first14=Susan L. |last15=Worthley |first15=Daniel L. |date=2023-08-11 |title=Engineered bacteria detect tumor DNA |journal=Science |language=en |volume=381 |issue=6658 |pages=682–686 |doi=10.1126/science.adf3974 |issn=0036-8075 |pmc=10852993 |pmid=37561843|bibcode=2023Sci...381..682C }}</ref> Although not yet ready for clinical use, these biosensors demonstrate advantages over traditional in vitro DNA analysis by capturing and preserving DNA in situ, avoiding degradation by gastrointestinal DNases. Future developments aim to enhance their signal-to-background ratio and improve biocontainment to minimize risks such as antibiotic resistance spread. Additionally, the ability to couple DNA detection with therapeutic delivery systems, such as nanobodies and peptides, presents exciting possibilities for disease management.<ref name=":112" />
''A. baylyi's'' natural transformation abilities have been employed to monitor environmental pollution through engineered biosensors that respond to specific pollutants with bioluminescence. These biosensors can detect contaminants in real time, enabling the tracking of degradation processes in soil and water. This application highlights ''A. baylyi's'' potential as a powerful tool for ecological monitoring and environmental remediation.<ref name=":112" />
Similarly, natural transformation contributes to using ''A. baylyi'' to detect antibiotic resistance genes acquired through horizontal gene transfer. Research on lettuce plants revealed that ''A. baylyi'' can incorporate and transfer resistance genes from the plant surface into internal tissues. These findings highlight its utility as a model organism for studying gene transfer in agricultural and environmental systems and its potential implications for managing antibiotic resistance.<ref name=":02"/>
==References== {{Reflist}}<ref>{{Cite journal |last1=Riva |first1=Valentina |last2=Patania |first2=Giovanni |last3=Riva |first3=Francesco |last4=Vergani |first4=Lorenzo |last5=Crotti |first5=Elena |last6=Mapelli |first6=Francesca |date=2022-09-10 |title=Acinetobacter baylyi Strain BD413 Can Acquire an Antibiotic Resistance Gene by Natural Transformation on Lettuce Phylloplane and Enter the Endosphere |journal=Antibiotics |language=en |volume=11 |issue=9 |page=1231 |doi=10.3390/antibiotics11091231 |doi-access=free |issn=2079-6382 |pmc=9495178 |pmid=36140010}}</ref>
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Category:Moraxellaceae Category:Bacteria described in 2003