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Magnetospirillum edit
Magnetospirillum is a genus of Magnetotactic bacteria (MTB), the smallest known organism to undergo a biomineralization process to form magnetosomes.[1] Magnetospirillium form an average of 13 of these magnetosomes per cell[1].
Table 1 edit
Characteristics of Magnetospirillum magnetotacticum.
Morphological, physiological, and biochemical characteristics of Magnetospirillum magnetotacticum are shown in the Table below.
| Test type | Test | Characteristics |
| Colony characters | Size | ~0.5 to >3 μm |
| Type | Spirillum | |
| Color | n/a | |
| Shape | geometrical | |
| Arrangement | chain/chaotic | |
| Morphological characters | Shape | geometrical |
| Physiological characters | Motility | + |
| Growth at 6.5% NaCl | + | |
| Biochemical characters | Gram staining | - |
| Oxidase | + | |
| Catalase | - | |
| Oxidative-Fermentative | - | |
| Motility | + | |
| Methyl Red | n/d | |
| Voges-Proskauer | n/d | |
| Indole | n/d | |
| H2S Production | n/d | |
| Urease | n/d | |
| Nitrate reductase | + | |
| β-Galactosidase | n/d | |
| Hydrolysis of | Gelatin | - |
| Casein | - | |
| Utilization of | Glycerol | n/d |
| Galactose | n/d | |
| D-Glucose | n/d | |
| D-Fructose | n/d | |
| D-Mannose | n/d | |
| Mannitol | n/d |
Note: + = Positive, - = Negative, n/d= Not Determined
Magnetosomes edit
Magnetosomes are an organelle found in magnetotactic bacteria, such as the magnetospirillum genus. The magnetosomes are lipid bound organelles that are responsible for the direction of magnetic nanoparticles, greigite (Fe3S4) and magnetite (Fe3O4)[2]. Magnetospirillum are commonly used as model organisms to study magnetosomes as much is yet to be known about their use and formation.[3]
Formation edit
For magnetosomal formation, the cell must first maintain a content of reactive oxygen to maintain the content of ferric and ferrous iron.[4]There is a lag phase that occurs for approximately 0.5-2 hours[1]. After the lag phase, an intermediate to the nanoparticle magnetite is developed and is very Fe(III)-rich[2].
Shape and Arrangement edit
Magnetosomes form geometric patterns such as prisms, cuboctehedrons, and bullet shaped[3]. They are arranged in linear formation down the long axis of the bacterium, although some have been found to have chaotic arrangements[3].
Habitat edit
Magnetosomes are found in the aquatic and sedimentary environments. That includes ponds, lakes, oceans, and meadows[5]. This area of topic is still under great study.
Conjugation edit
This genus can transmit DNA via conjugation. The donor bacteria (the bacterium who will be donating its DNA) contains a fertilization factor (F+) which allows it to conjugate[6]. F- denotes the recipient cell that does not contain the fertilization factor[6]. A structure called the relaxasome is formed and a sex plus extends from the donor cell to the recipient cell, pulling the two together[6]. The DNA is transmitted via the relaxasome. The sex pilus detaches and the relaxasome disassembles and the conjugation process is complete.
For these organisms specifically, another process must take place in order to ensure that magnetosomes enter both daughter cells. MamK is an actin like protein and is used to hold the chain of magnetosomes together; a static chain is required for equal distribution[7].
Transduction edit
Magnetosomes have the ability to transfer genetic material via a process known as transduction. Using methyl-accepting chemotaxis protens (MCPs), the needed information is transferred to flagellar motor switch protein. During this process of chemotaxis, it has shown that information that transfers is responsible for the change in the magnetic field[8].
Genome edit
Magnetospirillum have a unique genome that categorizes them as Magnetotactic bacteria. The magnetic genomic cluster (MGC) is a location where the gene that is specific to magnetosome formation is found[4]. This gene is responsible for the size, shape, and formation of the magnetosomes.Magnetotactic bacteria is then able to orient themselves along the magnetic field, allowing them to change their location when needed[9]. Magnetosomes are one of the examples of lipid-bound intracellular organelle. With this knowledge, it makes magnetosomes extremely intriguing from a biological perspective, as well as the possibility for technological applications[10].
Uses edit
MTB, specifically the magnetosomes that make them unique, are helping make many technological advancements.
Cancer Treatment edit
The further research of magnetosomes is helpful in the development of cancer treatments. Tumor hypothermia treatment is a way of killing cancerous tissue through the heating of magnetosomes[11].
Wastewater Treatment edit
Because MTB use metal ions as part of their magnetosomes, the use of MTB's has shown helpful in the treatment of wastewater. Metal wastewater can be treated with magnetotactic bacteria in order to absorb the metal ions[11].
References edit
- ^ a b c Le Nagard, Lucas; Zhu, Xiaohui; Yuan, Hao; Benzerara, Karim; Bazylinski, Dennis A.; Fradin, Cécile; Besson, Adrien; Swaraj, Sufal; Stanescu, Stefan; Belkhou, Rachid; Hitchcock, Adam P. (2019-12-30). "Magnetite magnetosome biomineralization in Magnetospirillum magneticum strain AMB-1: A time course study". Chemical Geology. 530: 119348. doi:10.1016/j.chemgeo.2019.119348. ISSN 0009-2541.
- ^ a b Wan, Juan; Browne, Patrick J.; Hershey, David M.; Montabana, Elizabeth; Iavarone, Anthony T.; Downing, Kenneth H.; Komeili, Arash (2022-02-02). "A protease-mediated switch regulates the growth of magnetosome organelles in Magnetospirillum magneticum". Proceedings of the National Academy of Sciences. 119 (6): e2111745119. doi:10.1073/pnas.2111745119. ISSN 0027-8424.
- ^ a b c Zwiener, Theresa; Dziuba, Marina; Mickoleit, Frank; Rückert, Christian; Busche, Tobias; Kalinowski, Jörn; Uebe, René; Schüler, Dirk (2021-12). "Towards a 'chassis' for bacterial magnetosome biosynthesis: genome streamlining of Magnetospirillum gryphiswaldense by multiple deletions". Microbial Cell Factories. 20 (1): 35. doi:10.1186/s12934-021-01517-2. ISSN 1475-2859. PMC 7860042. PMID 33541381.
{{cite journal}}: Check date values in:|date=(help)CS1 maint: PMC format (link) CS1 maint: unflagged free DOI (link) - ^ a b Gareev, Kamil G.; Grouzdev, Denis S.; Kharitonskii, Petr V.; Kosterov, Andrei; Koziaeva, Veronika V.; Sergienko, Elena S.; Shevtsov, Maxim A. (2021-06-18). "Magnetotactic Bacteria and Magnetosomes: Basic Properties and Applications". Magnetochemistry. 7 (6): 86. doi:10.3390/magnetochemistry7060086. ISSN 2312-7481.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Lin, Wei; Bazylinski, Dennis A.; Xiao, Tian; Wu, Long-Fei; Pan, Yongxin (2013-11-12). "Life with compass: diversity and biogeography of magnetotactic bacteria". Environmental Microbiology. 16 (9): 2646–2658. doi:10.1111/1462-2920.12313. ISSN 1462-2912.
- ^ a b c Slonczewski, Joan L. MICROBIOLOGY : An Evolving Science. S.L., W W Norton, 2020.
- ^ Taoka, Azuma, et al. “Tethered Magnets Are the Key to Magnetotaxis: Direct Observations of Magnetospirillum Magneticum AMB-1 Show That MamK Distributes Magnetosome Organelles Equally to Daughter Cells.” MBio, vol. 8, no. 4, 6 Sept. 2017, 10.1128/mbio.00679-17. Accessed 25 Apr. 2022.
- ^ Chen; Zhang; Chen; Cai; Zhang; Song; Wu, Haitao; Shen-Da; Linjie; Yao; Wei-Jia; Tao; Long-Fei (17 July 2018). "Efficient Genome Editing of Magnetospirillum magneticum AMB-1 by CRISPR-Cas9 System for Analyzing Magnetotactic Behavior". Retrieved 25 April 2022.
{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: url-status (link) - ^ Smalley, Matthew D.; Marinov, Georgi K.; Bertani, L. Elizabeth; DeSalvo, Gilberto (2015-04-02). "Genome Sequence of Magnetospirillum magnetotacticum Strain MS-1". Genome Announcements. 3 (2): e00233–15. doi:10.1128/genomeA.00233-15. ISSN 2169-8287. PMC 4384492. PMID 25838488.
- ^ Smalley, Matthew D.; Marinov, Georgi K.; Bertani, L. Elizabeth; DeSalvo, Gilberto (2015-04-02). "Genome Sequence of Magnetospirillum magnetotacticum Strain MS-1". Genome Announcements. 3 (2): e00233–15. doi:10.1128/genomeA.00233-15. ISSN 2169-8287. PMC 4384492. PMID 25838488.
- ^ a b Alphandery, E., Faure, S., Seksek, O., Guyot, F., & Chebbi, I. (2011). Chains of magnetosomes extracted from AMB-1 magnetotactic bacteria for application in alternative magnetic field cancer therapy. ACS nano, 5(8), 6279-6296.