''Sorangium cellulosum'' is a soil-dwelling
Gram-negative
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...
bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...
of the group
myxobacteria
The myxobacteria ("slime bacteria") are a group of bacteria that predominantly live in the soil and feed on insoluble organic substances. The myxobacteria have very large genomes relative to other bacteria, e.g. 9–10 million nucleotides except ...
. It is motile and shows
gliding motility Gliding motility is a type of translocation used by microorganisms that is independent of propulsive structures such as flagella, pili, and fimbriae. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms of ...
. Under stressful conditions this motility, as in other myxobacteria, the cells congregate to form
fruiting bodies
The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cyc ...
and differentiate into myxospores. These congregating cells make isolation of
pure culture and colony counts on
agar
Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori (''Gracilaria'') and "tengusa" (''Gelidiaceae''). As found in nature, agar i ...
medium difficult as the bacterium spread and colonies merge.
It has an unusually-large genome of 13,033,779 base pairs, making it the largest bacterial genome sequenced to date by roughly 4 Mb.
Ecology
''S. cellulosum'' is found in soils, animal feces, and tree bark.
The bacterium is a
saprophyte deriving its nutrition from cellulose aerobically. It is a prolific producer of secondary
fungicides
Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality ...
and
bactericide
A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics.
However, material surfaces can also have bactericidal properties based solely on their ...
s that reduce competition in soil environments. In lab samples, ''S. cellulosum'' grows on agar medium only when certain cell densities are plated.
Quorum-sensing allows Sorangium to grow in communities sufficiently large to metabolize cellulose.
Secondary compounds
''Sorangium'' produces 50% of all known metabolites produced by myxobacteria.
These include compounds that are antifungal, antibacterial, antibiotic resistant, or can even disable mammalian cells. These many compounds have sparked intense mining of its extensive
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...
in exploration of possible industrial and medical applications. Some of these
secondary compounds include:
*Ambruticin and Jerangolid A - Antifungal agents.
*Chivosazol - a compound that destroys the actin skeleton of eukaryotic cells. It is effective against
both fungal and mammalian cells.
*
Epothilones - Compounds that target microtubule function leading to
apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes ( morphology) and death. These changes in ...
. Some derivatives are used to treat human cancers.
*Myxochelin A - Antibacterial agent that acts by sequestering iron in the environment.
*Soraphen A - An agent highly effective against plant-pathogenic fungi. It was extensively researched for agricultural use until it was discovered to be a
teratogen.
Industrial fermentation
Industrial fermentation is the intentional use of fermentation in manufacturing products useful to humans. In addition to the mass production of fermented foods and drinks, industrial fermentation has widespread applications in chemical industry. ...
and
genetic manipulation of ''S. cellulosum'' is challenging.
Plasmids
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; how ...
have been found to not function in ''S. cellulosum'' cells. Reproducible genetic alterations must be made directly into the single circular chromosome.
Clinical use
Metabolites
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, ...
secreted by ''Sorangium cellulosum'' known as
epothilones have been noted to have
antineoplastic activity.
This has led to the development of
analogs which mimic its activity. One such analog, known as
ixabepilone is a
U.S. Food and Drug Administration approved chemotherapy agent for the treatment of
metastatic
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
breast cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or ...
.
Ixabepilone
/ref>
References
External links
Type strain of ''Sorangium cellulosum'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q2523108
Gram-negative bacteria
Myxococcota