User talk:Pavneet Kalsi

While discussing the numerical values of the thickness of peptidoglycan in bacteria, the author fails to provide a citation when presenting hard facts. In addition, the values provided for the thickness of the gram-negative peptidoglycan layer, 7-8 nanometers, are inaccurate and should be changed to 5-10 nanometers.

Subsequently, the values for the percent dry weight composition of peptidoglycan in gram-positive and gram-negative bacteria are also not validated with a reliable source. Due to the difficulty in finding a source, the author can use percent peptidoglycan composition of the cell wall, which is over 50% in gram-positive and about 10-20% in gram negative bacteria , instead of dry weight as a comparison. Furthermore, improper referencing is also showcased when providing absolutes which implies a possible misunderstanding about peptidoglycan composition in species. For example, instead of stating peptidoglycan makes up “10% of gram-negative strains,” a range of percentages should have been provided, as suggested above, to holistically exemplify the diversity of peptidoglycan composition in different species.

Also, reliable sources are not successfully provided with citation 1 and 5. The hyperlink 5 does not work which impairs the ability to check facts. In addition, when discussing the formation of the 3-D mesh layer with citation 1, the author could have used reliable resources with images (Fig. 2-8, Fig. 1, Fig. 3) instead of an animation if visual understanding was intended. The website PharmaXChange.info has a purpose of providing free information to “make education fun and interesting” rather than it being a neutral source with a reliable publisher. Pavneet Kalsi (talk) 20:20, 17 September 2017 (UTC)

Welcome!

Hello, Pavneet Kalsi, and welcome to Wikipedia! My name is Ian and I work with the Wiki Education Foundation; I help support students who are editing as part of a class assignment.

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If you have any questions, please don't hesitate to contact me on my talk page. Ian (Wiki Ed) (talk) 18:53, 22 September 2017 (UTC)

The article on magnetotaxis requires improvement as it is of high notability but is not holistically represented on its wikipedia page. The process of magnetotaxis has had significant coverage, as the main topic in secondary resources, from 20 years after its discovery to 2016 as an example. The initial research conducted provides an overview of magnetotaxis which then progresses to the synthesis of its core organelle, magnetosome, responsible for magnetotaxis . Interest on magnetotaxis has not only been for a long period of time, but also in diverse fields rather than just microbiology. This interest was due to the complexity of the magnetosome leading to multidisciplinary efforts in further understanding magnetotaxis and magnetosomes and establishing independent resources with new data . Reliable resources have conducted research on many aspects of magnetotactic bacteria, who conduct magnetotaxis, like ecology, diversity, habitat, evolution of magnetosomes, etc. highlighting its in depth coverage .

The deficiencies of this article emerge from its short length incapable of providing detail on key aspects of magnetotaxis. Specifically, the author only mentions the organelle magnetosome in one sentence when it is vital for magnetotaxis in bacteria. Thus, expansion should have been provided as in a variety of notable journals. For example, the author could have mentioned the evolution of the the magnetosome and dispersion of this phenotype in a variety of bacteria . In addition, the unique structure could have been further conveyed by providing a picture, looking at the number, size, shape, macromolecule and chemical composition of the internal and external structural components . Lastly, the author does not connect the structure of the magnetosome to its function and advantages in the environment .

The authors lack of further details could have been due to only recent discoveries in genome sequencing technologies for isolating and cultivating magnetotactic bacteria and looking into the magnetosome. These findings, based on new technology, allowed for further interest in multiple disciplines making deeper understanding possible. This then leads to generating more published papers on different aspects of the magnetosome which others may not have had access to in earlier years . Pavneet Kalsi (talk) 04:35, 28 September 2017 (UTC)

Magnetosome

Magnetosomes are organelles found in gram negative, motile, and rod shaped magnetotactic bacteria . Its structural features consist of an outer membrane composed of proteins, fatty acids, glycolipids, sulfolipids, and phospholipids . These membrane proteins conduct biomineralization . Therefore, the membrane surrounds crystals composed of magnetite (Fe3O4) or an iron-sulfide compound (Fe3S4) which respond to the magnetic field . These high quality crystals form one of three common shapes-- cuboidal, parallelepipedal/ elongated prism, or bullet/ tooth with no symmetry . Magnetosomes range in size from 35-120 nm, and they usually align as dark chains perpendicular to the long axis of the cell . The length of the chain varies in different bacteria . Furthermore, some species have multiple chains, chains with multiple strands, or clusters of magnetosomes .

The long chain(s) of magnetosomes are responsible for conducting magneto-aerotaxis/magnetotaxis . They create a permanent, single magnetic dipole that aligns with the magnetic field . This directs the motility of bacteria along magnetic field lines in the direction of a microaerophilic environment . Magneto-aerotaxis is conducted in a passive manner when moving away from high oxygen gradients . In contrast, bacteria without magnetosomes direct their movement using chemotaxis. Magneto-aerotaxis is showcased in situations where magnetotactic bacteria are isolated from their environment due to an external force (e.g. flood) . They then return to their preferred habitat via polarized orientation. Furthermore, magnetotactic bacteria are able to move away from increasing oxygen concentrations faster when compared to wild type bacteria placed in a zero field . This is not due to an increase in average speed in situations of high oxygen concentration but enhanced oxygen detection also possible because of magnetosomes .Pavneet Kalsi (talk) 00:13, 20 November 2017 (UTC)