Paenarthrobacter ureafaciens KI72
Classification
Bacteria; Terrabacteria; Actinobacteria; Actinomycetia; Micrococcales; Micrococcaceae;
Species
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NCBI: [2] |
Paenarthrobacter Ureafaciens
Strain: K172
Description and Significance
Discovered in the waste pools outside of nylon factories in 1975, these bacteria were first classified as Achromobacter guttatus KI72 [3], then in 1980 was reclassified as Flavobacterium sp. KI72[4], reclassified in 2017 to Arthrobacter sp. KI72 [5], although the NCBI database updated in 2021 to follow a classification made by the Genome Taxonomy Database which is the modern day Paenarthrobacter ureafaciens KI72 [6]. The bacteria inhabits pool of nylon waste since the bacteria produces what is commonly referred to as nylonase but is instead referred to as 6-Aminohexanoate-dimer Hydrolase. 6-Aminohexanoate-dimer Hydrolase is able to break an important linkage in nylon-6 waste which is not biodegradeable until the discovery of Paenarthrobacter ureafaciens KI72. Also, is it note worthy that only in 1975 was when this bacteria was being discovered , meaning that the pan genome of the ancestor of KI72 was modified to produce nylonase which can serve to be an important example in teaching evolution.
Genome Structure
The genome consists of 4,568,574 bp split among three different plasmids named pOAD1 (39.7 kbp), pOAD2 (43.6 kbp), and pOAD3 (56.3 kbp) with a total of 4,372 coding DNA sequences, 54 tRNA, and six rRNA [7]. pOAD2 contains the three coding regions for the nylonase enzyme which includes the regions: nlyA which serves to cleave the 6-aminohexanoic acid cyclic dimer to form a straight chain [8], nlyB which simply supports nylA in nylon degradation [9], and nylC which is used to degrade cyclic and linear oligomers of 6-aminohexanoate [10].
Cell Structure, Metabolism and Life Cycle
The bacterium is bacillus shaped and inhabits pools of nylon waste products called 6-aminohexanoate oligomers. These oligomers are typically not biodegradeable and can linger for long periods of time in the environment if not properly disposed of. KI72 is able to use 6-aminohexanoate oligomers strictly as both a carbon and nitrogen source due to being able to fully break the waste product down into adipate semialdehyde and eventually to adipate [11]. To degrade nylon 1,6 oligomeres, Paenarthrobacter ureafaciens KI72 uses three different enzymes (nlyA, nlyB, and nlyC or EI, EII, EIII respectively). nylA and nylC are used to break different cyclical forms of nylon down into a straight chain for nylB to break each oligomere off one by one [12]
Ecology and Pathogenesis
As mentioned prior, the bacterium tends to inhabit pools of nylon-6 waste products and subsist off the carbon and nitrogen from the breakdown of the waste products. Seeing as the KI72 strain is able to break down normally long-lasting synthetic materials from the environment, it is an important industrial bacterium to reduce the human impact of mass scale manufacturing done by humans. However, there has been evidence that the ureafaciens species is able to cause cystites formation in labratory grown cells if exposed to tetracycline and some antibiotics [13].
References
1. Wink J. Compendium of Actinobacteria http://www.dsmz.de/microorganisms/wink_pdf/DSM20126.pdf
2.Paenarthrobacter ureafaciens. NCBI. https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=37931
3. Kinoshita S, Kageyama S, Iba K, Yamada Y, Okada H. 1975. Utilization of a Cyclic Dimer and Linear Oligomers of ε-Aminocaproic Acid by Achromobacter guttatus KI 72. Agricultural and Biological Chemistry, Volume 39, Issue 6, Pages 1219-1223https://doi.org/10.1271/bbb1961.39.1219
4. Negoro S, Shinagawa H, Nakata A, Kinoshita S, Hatozaki T, Okada H. 1980. Plasmid Control of 6-Aminohexanoic Acid Cyclic Dimer Degradation Enzymes of Flavobacterium sp. K172. ASM Journals, Journal of Bacteriology Vol. 143, No. 1. https://doi.org/10.1128/jb.143.1.238-245.1980
5 & 7. Takehara I, Kato D, Takeo M, Negoro S. 2017. Draft Genome Sequence of the Nylon Oligomer-Degrading Bacterium Arthrobacter sp. Strain KI72. ASM Journals, Genome Announcements Vol. 5, No. 17. https://doi.org/10.1128/genomeA.00217-17
6. GCF_002049485 Paenarthrobacter ureafaciens. GTDB Genome Database.1https://gtdb.ecogenomic.org/genome?gid=GCF_002049485.1
8. Uniport, nylA. https://www.uniprot.org/uniprotkb/P13398/entry
9. Uniport, nylB. https://www.uniprot.org/uniprotkb/P07061/entry
10. Uniport, nylC https://www.uniprot.org/uniprotkb/Q79F77/entry
11.Takehara I, Fujii T, Tanimoto Y, et al. 2018. Metabolic pathway of 6-aminohexanoate in the nylon oligomer-degrading bacterium Arthrobacter sp. KI72: identification of the enzymes responsible for the conversion of 6-aminohexanoate to adipate. Appl Microbiol Biotechnol 102, 801–814. https://doi.org/10.1007/s00253-017-8657-y
12. Truman R. 2015. Nylon-eating bacteria: part 1—discovery and significance. JOURNAL OF CREATION 29(1):95-102. https://www.researchgate.net/publication/347951444_Nylon-eating_bacteria_-_part_1_-_discovery_and_significance_J_of_Creation_29195-102_2015
13. Tanaka N, Uchimura T, Komagata K. 2001. The formation and structures of cystites of Arthrobacter ureafaciens NRIC 0157T induced by antibiotics. The Journal of General and Applied Microbiology Volume 47 Issue 2 Pages 85-97. https://www.jstage.jst.go.jp/article/jgam/47/2/47_2_85/_article
Author
Page authored by Stefan Magheru, student of Prof. Bradley Tolar at UNC Wilmington.
