Editing Mycobacterium smegmatis (section)

===Use in research===
''Mycobacterium smegmatis'' is useful for the research analysis of other ''Mycobacteria'' species in laboratory experiments.  ''M. smegmatis'' is commonly used in work on the ''Mycobacterium'' genus due to it being a "fast grower" and non-pathogenic. ''M. smegmatis'' is a simple model that is easy to work with, i.e., with a fast [[doubling time]] and only requires a [[biosafety level]] 1 laboratory.  The time and heavy infrastructure needed to work with pathogenic species prompted researchers to use ''M. smegmatis'' as a model for mycobacterial species.{{cn|date=April 2023}}

''Mycobacterium smegmatis'' shares the same peculiar cell wall structure of [[Mycobacterium tuberculosis|''M. tuberculosis'']] and other mycobacterial species.<ref>{{cite journal |vauthors=King GM |title=Uptake of carbon monoxide and hydrogen at environmentally relevant concentrations by mycobacteria |journal=Applied and Environmental Microbiology |volume=69 |issue=12 |pages=7266–7272 |date=December 2003 |pmid=14660375 |pmc=310020 |doi=10.1128/aem.69.12.7266-7272.2003}}</ref> It is also capable of oxidizing carbon monoxide aerobically, as is ''M. tuberculosis.''{{cn|date=April 2023}}

Bacterial secretion systems are specialized protein complexes and pathways that allow bacterial pathogens to secrete proteins across their cell membranes and, ultimately, to host cells. These effector proteins are important virulence factors, which allow the pathogen to survive inside of the host. There are many different kinds of specific secretion systems, and ''M. tuberculosis'' has an Snm (secretion in mycobacteria) protein secretion system, now called the ESX secretion system. Although the ESX secretion system is a key in determining ''M. tuberculosis'' virulence, all mycobacteria have genes encoding the components of this system. This area of the genome is referred to as the RD1 locus. ''M. smegmatis'' is commonly used to study ESX secretion because of its genetic similarities  and analogous function to ''M. tuberculosis'', as well as ease of growing in the lab. One example of how this can be applied in research is the identification of gene products required for ESX secretion. By knocking out genes in the RD1 locus of ''M. smegmatis'' and testing efficiency of ESX secretion before and after gene knockout, specific genes can be identified as necessary for ESX secretion. These findings can be applied to the ESX secretion system of ''M. tuberculosis''.<ref>{{Cite journal |last1=Converse |first1=Scott E. |last2=Cox |first2=Jeffery S. |date=2005-02-15 |title=A Protein Secretion Pathway Critical for Mycobacterium tuberculosis Virulence Is Conserved and Functional in Mycobacterium smegmatis |journal=Journal of Bacteriology |language=en |volume=187 |issue=4 |pages=1238–1245 |doi=10.1128/JB.187.4.1238-1245.2005 |issn=0021-9193 |pmc=545616 |pmid=15687187}}</ref>

''Mycobacterium smegmatis'' is readily cultivatable in most synthetic or complex laboratory media, where it can form visible colonies in 3–5 days. These properties make it a very attractive model organism for ''M. tuberculosis'' and other mycobacterial pathogens. ''M. smegmatis'' mc<sup>2</sup>155 is also used for the cultivation of [[mycobacteriophage]].{{cn|date=April 2023}}