Sphingomonas was defined in 1990 as a group of Gram-negative, rod-shaped, chemoheterotrophic, strictly Aerobic organism bacteria. They possess ubiquinone 10 as their major respiratory quinone, contain glycosphingolipids (GSLs), specifically ceramide, instead of lipopolysaccharide (LPS) in their cell envelopes, and typically produce yellow-pigmented colonies. The GSL serves to protect the bacteria from Antibiotic. Unlike most Gram-negative bacteria, Sphingomonas cannot carry endotoxins due to the lack of lipopolysaccharides, and has a Hydrophobe surface characterized by the short nature of the GSL's carbohydrate portion.
By 2001, the genus included more than 20 species that were quite diverse in terms of their phylogenetic, ecological, and Physiology properties. As a result, Sphingomonas was subdivided into different genera: Sphingomonas, Sphingobium, Novosphingobium, Sphingosinicella, and Sphingopyxis. These genera are commonly referred to collectively as sphingomonads. Distinct from other sphingomonads, Sphingomonas genomic structure includes a unique lipid formation, major 2-OH , homospermidine as the primary polyamine, and signature nucleotide bases within the 16S rRNA gene. The bacteria hold 3,914 proteins, 70 Non-coding RNA, and 3,948,000 base pairs (incomplete observation).
Habitat
The sphingomonads are widely distributed in nature, having been isolated from many different land and water habitats, as well as from plant root systems, clinical specimens, and other sources; this is due to their ability to survive in low concentrations of nutrients, as well as to metabolize a wide variety of carbon sources. Numerous strains have been isolated from environments contaminated with toxic compounds, where they display the ability to use the contaminants as nutrients.
[ Sphingomonas, Microbewiki]
Role in disease
Some of the sphingomonads (especially
Sphingomonas paucimobilis) also play a role in human disease, primarily by causing a range of mostly
nosocomial, non-life-threatening
that typically are easily treated by
antibiotic therapy.
[ Sphingomonas paucimobilis Bloodstream Infections Associated with Contaminated Intravenous Fentanyl, Lisa L. Maragakis, Romanee Chaiwarith, Arjun Srinivasan, Francesca J. Torriani, Edina Avdic, Andrew Lee, Tracy R. Ross, Karen C. Carroll, and Trish M. Perl, Emerging Infectious Diseases Vol. 15, No. 1, January 2009] In contrast, the seed-
endophyte strain
Sphingomonas melonis ZJ26 that can be naturally enriched in certain
Oryza sativa cultivars, confers diseases resistance against a bacterial pathogen and is vertically transmitted among plant generations via their seeds.
Applications
Biotechnological utilization
Due to their
Biodegradation and
biosynthetic capabilities, sphingomonads have been used for a wide range of biotechnological applications, from
bioremediation of environmental contaminants to production of extracellular polymers such as
sphingans (e.g.,
gellan gum,
welan, and
rhamsan) used extensively in the food and other industries.
The shorter
carbohydrate moiety of GSL compared to that of LPS results in the cell surface being more
hydrophobic than that of other Gram-negative bacteria, probably accounting for both
Sphingomonas' sensitivity to hydrophobic
antibiotics and its ability to
biodegradation hydrophobic polycyclic aromatic hydrocarbons.
[ One strain, Sphingomonas sp. 2MPII, can degrade 2-methylphenanthrene.][
] In May 2008, Daniel Burd, a 16-year-old Canadian, won the Canada-Wide Science Fair in Ottawa after discovering that Sphingomonas can degrade over 40% of the weight of plastic bags (polyethylene) in less than three months.[ TheRecord.com—CanadaWorld—WCI student isolates microbe that lunches on plastic bags]
A Sphingomonas sp. strain BSAR-1 expressing a high activity alkaline phosphatase (PhoK) has also been applied for bioprecipitation of uranium from alkaline solutions. The precipitation ability was enhanced by overexpressing PhoK protein in E. coli. This is the first report of bioprecipitation of uranium under alkaline conditions.[
]
Wine fermentation
Wine, developed through the alcoholic fermentation of grapes, is an alcoholic beverage that is sensorially characterized by micro-bacteria and a host of other environmental factors. While historic variables such as location, temperature, soil quality, and winemaking practices play a role in altering the taste of a wine, microbial biogeography plays a significant role in the quality of wine. A terroir, comprising the aforementioned characteristics, influences the quality of the wine grapes based on the unique vineyard region that it originates from.
While most microbiota cannot survive the wine fermentation process, Sphingomonas, found in soil, grape leaves, and on fermentation surfaces, can survive this process. The pigmentation, stress resistance levels, unique restorative DNA system, and low nutrient necessity allows further growth in the phyllosphere.
