Planctomyces
Sarah Abate
History
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First described by Gimesi in 1924 in
Budapest, Hungar.
Mistakenly identified as planctonic
fungus.
Schlesner and Stackebrandt assign
Planctomyces and Pirellula to the order
Planctomycelates.
Classification
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Phylum: Planctomycetes
Division: Planctomycetacia
Order: Planctomycetales
Family: Planctomycetaceae
Genera: Planctomyce, Pirellula, Gemmata,
Isophaera
Key Species: P. maris, P. limnophilus, P.
bekefii, I. pallida, G.obsriglobus.
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Morphology
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Gram negative, but contains no
peptidoglycan in it’s cell wall.
Mesophiles, few thermophiles.
4 main cell shapes
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Spherical
Ovoid
Ellipsoidal
Teardrop
Morphological Features
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Pili- used for adhesion of cells during aggregation.
May also be used to pass genetic information from
one cell to another.
Flagella- used for motility
Stalks- Used to anchor bacterium during budding
Crateriform structures- Pits within the cell surface
that are about 12nm in diameter. Function is
unknown.
Some contain an unique polar unicorn prosthecalike projection. Function is also unknown.
Planctomyces brasiliensis
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Small arrow pointing
to the unicorn like
projection.
Larger arrow
pointing to a
crateriform
structure.
Bar = 0.5
micrometers
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Cell Wall
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Contains no peptidogylcan. Very unique.
Cell wall is made of S-layer proteins
consisting of mainly proline and cysteine.
Reason for these proteins is unclear.
This causes Planctomyces to be very
resistant to Beta-lactam antibiotics such as
penicillin.
Lacks murein.
Reproduction
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Reproduces by
budding
Bud develops as a
small protuberance
at a particular
location called the
reproductive pole
and enlarges before
separation from the
mother cell.
Dimorphic Life Cycle
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Daughter or Swarmer
Cell
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Free swimming using
flagellum.
Mother or Vegetative
Cell
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No flagellum
Produce stalk that
anchors it to surfaces
Surfaces are usually
algae or cyanobacteria
Only after it attaches to a
surface does
reproduction begin.
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Metabolism
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Typically facultative aerobic
chemoorganotrophs.
Grow by fermentation or the respiration of
sugars.
Can degrade chitin.
Anaerobic ammonium-oxidizing: anaerobic
chemolithoautotrophs (Anammox)
Anammox
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Anaerobic Ammonia Oxidation
NH4+ + NO2- > N2 + 2H2O
Anammox process confirmed and
verified Mulder et al., 1995, Jetten et al.,
1999
Identified as planctomycetes (Strous et
al., 1999)
Anammox Process
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Anaerobic – anammox completely inhibited at
low oxygen concentrations
Enzyme hydroxylamine oxidoreductase
catalyzes oxidation of hydrazine and
hydroxylamine
Located in membrane-bound structure called
‘anammoxosome’
Membrane surrounding anammoxosome
made up of ladderane lipids (unique)
Ecology
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Fresh and salt water
Acid water bogs
Hot springs
Cattle manure
Garbage dumps
Rice paddies
Planctomyces maris
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Mesophile
Optimal growth temp. is 30-33 degrees Celsius.
Obligate aerobe
Carbon sources: glucose, galactose, mannose,
rhamnose, xylose, maltose, cellobiose,furanose,
treholose, N-acetlyglucosamine, glucuronic, lactic
acid, pectin, aesculin
Very slow growing
Growth requirements: 1.5-4.0% sodium chloride
Gemmata obscuriglobus
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Arrow is pointing to a
double membrane
bound organelle.
The nuclear body,
envelops the nucleoid
and all the cell’s DNA
as well as ribosome-like
material.
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Planctomyces limnophilus
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Mesophile
Optimal growth temp. is 30-32 degrees
Celsius
Freshwater bacterium
Grows best in pH between 6.2 and 7.0
NaCl tolerance of less than 1%
Carbon sources: D-glucose, D-galactose,
maltose, cellobiose, and N-acetlyglucosamine
Isophaera pallida
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Moderate thermophile
Optimal growth temp. is 41 degrees Celsius,
but can survive at 55 degrees Celsius.
Inhabits thermal springs
Lives is oxygen saturated water with
exposure to high solar radiation levels
Contains carotenoids even though it is not
phototrophic. Believed that it helps the
bacteria align itself with the radiation.
Planctomyces bekefii
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Lives solely in
polluted water
having pH of 6.8 to
9.4
Congregate to form
rosettes- formed by
individuals pointing
their stalks inward
and their cell bodies
outward.
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How can they be used.
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Anammox - nitrogen cycling in oceans
Anammox – biological wastewater
treatment
Pl. bekefii may serve as indicator of
eutrophic conditions
Questions?