Someone told me that microbial lysozyme has effect on gram negative bacteria but egg white lysozyme only affect gram positive bacteria. Is it true?

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    $\begingroup$ Whoever knows the answer to this question knows it by (a) having done the necessary experiments, or (b) having read the reports of those who had done the necessary experiments. Start with 'b' and if you don't find any such reports, continue with 'a.' $\endgroup$ – user37894 Sep 12 '18 at 17:19
  • $\begingroup$ I searched about documents to prove that but i can’t find any one $\endgroup$ – Mahmoud Oraby Sep 14 '18 at 11:41
  • $\begingroup$ Search the PubMed literature database . . . $\endgroup$ – user37894 Sep 14 '18 at 18:02

PubMed query: "lysozyme"[Title] returns 8673 papers (many of which contain useful data about the activities of bacterial- and chicken-type lysozyme/muramidase against Gram-positive and Gram-negative bacteria).

For example, Gajda & Bugla-Płoskońska (2014, Postepy Hig Med Dosw 21, 1501-1515) write:

Lysozyme (LZ, muramidase, N-acetylmuramylhydrolase) is a protein occuring in animals, plants, bacteria and viruses.

Lysozyme hydrolyzes the β-1,4 glycosidic bonds between N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) of cell wall peptidoglycan (PG) in Gram-positive and Gram-negative bacteria.

In the animal kingdom, three muramidase types have been identified: the c-type (chicken type), the g-type (goose-type) and the i-type (invertebrates).

Muramidase shows bactericidal activity mainly against Gram-positive bacteria. Cytolytic activity against cells of Gram-negative bacteria has not been proved.

Lysozyme hydrolyzes bacterial cell walls, which is why its muramidase activity is more effective against Gram-positive than Gram-negative bacteria, for the former have thicker cell walls. Whether or not there is any difference in the effectiveness between the bacterial- and chicken-type lysozyme can be found in the papers; i have not read them.

But one of the 8673 papers is titled Hen egg white lysozyme permeabilizes Escherichia coli outer and inner membranes (Derde et al., 2013, J Agric Food Chem. 16: 9922-9929).

The quick-and-dirty answer to the question, is it true that bacterial lysozyme affects Gram-negative bacteria but hen-egg (chicken-type) lysozyme only affects Gram-positive bacteria? is: No.

The 'slow-and-clean' answer can be found in those 8673 papers.

  • $\begingroup$ Thank you for your help, I already found this answer but i need to know the difference of the two type of lysozyme: a. Microbial lysozyme b. Egg white lysozyme on their effect on bacteria (is microbial lysozyme affect gram negative bacteria and egg lysozyme doesn’t ? $\endgroup$ – Mahmoud Oraby Sep 16 '18 at 0:47
  • $\begingroup$ @MahmoudOraby i edited my answer; you have everything you need to find the answer for yourself; or you can wait until someone else gives you a more detailed and comprehensive answer. $\endgroup$ – user37894 Sep 16 '18 at 1:49
  • $\begingroup$ @MahmoudOraby if you read 100 abstracts of "lysozyme" papers a day---which is doable---you will become lysozyme expert in 3 months (if that's what you would like to be). Of course, you can narrow your PubMed "lysozyme" search using logical operators (and, or) and additional keywords, and filter the results by publication type (e.g., Review)---this way you can get to the bottom of the pit faster . . . $\endgroup$ – user37894 Sep 16 '18 at 3:49
  • $\begingroup$ already I began to do that $\endgroup$ – Mahmoud Oraby Sep 16 '18 at 17:55

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