Epiphytic bacteria are
bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...
which live non-parasitically on the surface of a plant on various organs such as the leaves, roots, flowers, buds, seeds and fruit. In current studies it has been determined that epiphytic bacteria generally doesn't harm the plant, but promote the formation of ice crystals. Some produce an auxin hormone which promotes plant growth and plays a role in the life cycle of the bacteria.
Different bacteria prefer different plants and different plant organs depending on the organ's nutritional content, and depending on the bacteria's colonization system which is controlled by the host plant. Bacteria which live on leaves are referred to as
phyllobacteria, and bacteria which live on the root system are referred to as
rhizabacteria. They adhere to the plant surface forms as 1-cluster 2- individual bacterial cell 3- biofilm . The age of the organ also affects the epiphytic bacteria population and characteristics and has a role in the inhibition of
phytopathogen on plant. Epiphytic bacteria found in the marine environment have a role in the
nitrogen cycle
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, atmospheric, terrestrial ecosystem, terrestrial, and marine ecosystems. The conversion of nitrogen can ...
.
Species
There are diverse species of epiphytic bacteria. An incomplete list:
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Citrobacter youngae''
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Bacillus thuringiensis
''Bacillus thuringiensis'' (or Bt) is a gram-positive bacteria, gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide. ''B. thuringiensis'' also occurs naturally in the gut of caterpillars of various types ...
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Enterobacter soli
''Enterobacter'' is a genus of common Gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacteria of the family Enterobacteriaceae. Cultures are found in soil, water, sewage, feces and gut environments. It is the type genus o ...
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Bacillus tequilensis''
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Bacillus aryabhattai''
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Pantoea eucalypti''
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Pseudomonas palleroniana''
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Serratia nematodiphila
''Serratia'' is a genus of Gram-negative, facultatively anaerobic, rod-shaped bacteria of the family Enterobacteriaceae. They are typically 1–5 μm in length, do not produce spores, and can be found in water, soil, plants, and animals. Some mem ...
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Stenotrophomonas maltophilia
'' Stenotrophomonas maltophilia'' is an aerobic, nonfermentative, Gram-negative bacterium. It is an uncommon bacterium and human infection is difficult to treat. Initially classified as ''Bacterium bookeri'', then renamed ''Pseudomonas maltoph ...
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Pseudomonas mosselii''
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Pseudomonas putida
''Pseudomonas putida'' is a Gram-negative, rod-shaped, saprophytic soil bacterium. It has a versatile metabolism and is amenable to genetic manipulation, making it a common organism used in research, bioremediation, and synthesis of chemicals and ...
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Lysinibacillus xylanilyticus''
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Enterobacter asburiae''
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Acinetobacter johnsonii''
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Pseudomonas macerans''
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Serratia marcescens
''Serratia marcescens'' () is a species of bacillus (shape), rod-shaped, Gram-negative bacteria in the family Yersiniaceae. It is a facultative anaerobe and an opportunistic pathogen in humans. It was discovered in 1819 by Bartolomeo Bizio in Pa ...
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Classification
Many epiphytic bacteria are rod-shaped, and classified as either gram negative or gram positive, pigmented or non-pigmented, fermentative or non-fermentative .
Non-pigmented epiphytic bacteria have high a
GC content
In molecular biology and genetics, GC-content (or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates the proportion of G and C bases out of ...
in their
genome
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 genes, other functional regions of the genome such as ...
, a characteristic which protects the bacteria from the
ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...
rays of the sun. Because of this, these bacteria have special nutritional requirements.
Current studies on epiphytic bacteria are underway for biotechnological applications areas such as the promotion of plant growth. Epiphytic bacteria are removed from the plant surface through ultraviolet radiation, chemical surface disinfection, and washing .
[T. Boureau, M.-A. Jacques, R. Berruyer, Y. Dessaux, H. Dominguez and C.E. Morris. Comparison of the Phenotypes and Genotypes of Biofilm and Solitary Epiphytic Bacterial Populations on Broad-Leaved Endive]
See also
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Epiliths, organisms that grow on rocks
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Zoochory
In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant.
Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...
, seed dispersal by animals
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Epibiont
An epibiont (from the Ancient Greek meaning "living on top of") is an organism that lives on the surface of another living organism, called the basibiont ("living underneath"). The interaction between the two organisms is called epibiosis. An ep ...
, an organism that grows on another life form
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Foliicolous, lichens or bryophytes that grow on leaves
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Epiphyte
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...
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Endosymbiont
An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically the two organisms are in a mutualism (biology), mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), whi ...
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Epiphytic fungus
External links
* http://www.pjoes.com/pdf/12.1/83-93.pdf
References
{{Bacteria
Bacteria
Bacteriology
Botany