Katarzyna A.Katarzyna A. PaliPalińskańskaGeomicrobiology,

ICBM,CvO University of Oldenburg, Germany

Email: k.palinska@uniEmail: k.palinska@uni--oldenburgoldenburg.de.de

Eukaryotic microorganismsEukaryotic microorganismsand virusesand viruses

--AlgaeAlgae--

3.45 bya =

Cyanobacteria appear and introduce photosynthesis

1.5 bya =

first Eukaryotes appeared

400-500 mya = plants on land

Brief history of photosynthetic Brief history of photosynthetic organisms on earth…organisms on earth…

BotanyBotany = study of plants

PhycologyPhycology = study of algae (Latin)

AlgologyAlgology = less correct (close to the study of pain)(Greek)

alga (singular)

algae (plural)

algal (adj.)

“algaes” (wrong!)

•Photosynthesis (photoautotropic, usually), using Chl a asprimary pigmentBUT: Limited cellular differentiation compared toterrestrial plants

•no “real” vascular system

•sex organs unicellular or if multicellular -> “naked”“naked” reproductive structures (no sterile layer ofcells surrounding sex organs)

•In some cases: all cells capable of reproduction

•MUCH greater diversity of photosynthetic pigments

Defining characteristics of Defining characteristics of algaealgae

• several groups of relatively simple living aquatic organisms that capture light energy through photosynthesis, using it to convert inorganic substances into organic matter.

• polyphyletic group = different ancestors, differentevolutionary histories

•algae group includes prokaryotes (cyanobacteria) AND eukaryotes (green, brown, red algae) – traditional approach

• green, red, and brown algae are now thought to be in different kingdoms (some biologists place greens in Plantae)

What are algae?What are algae?

Separated from animalsSeparated from animals

• Algae produce spores (asexual reproductive • Algae produce spores (asexual reproductive cells) as wellcells) as well aas gametes (sexual cells).s gametes (sexual cells).

• Animals produce only gametes.• Animals produce only gametes.

LevelLevel: : suffixsuffix:: exampleexample::

Kingdom Kingdom ProtistaProtistaPhylum/Division Phylum/Division --phyta phyta ChlorophytaChlorophytaClass Class --phyceaephyceae ChlorophyceaeChlorophyceaeOrder Order --ales ales UlotrichalesUlotrichalesFamily Family --aceae aceae UlvaceaeUlvaceaeGenus Genus UlvaUlvaSpecies Species fenestratafenestrata

Algal taxonomyAlgal taxonomy• • KKing ing PPhillip hillip CCame ame OOverver FFor or GGood ood SSpaghettipaghetti• • KKeep eep DDishes ishes CClean lean OOr r FFamilyamily GGets ets SSickick

Hierarchical system of Hierarchical system of classification…classification…

Taxonomy/Taxonomy/systematicssystematicsconstantly underconstantly under

revisionrevision

-- depending on whodepending on whomm you ask, between 50,000 andyou ask, between 50,000 and10 million different algal 10 million different algal sppspp!!

How to define species???How to define species???

-- Biological species concept?Biological species concept?--Morphology?Morphology?

--Genetics?Genetics?

EUKARYOTES

PROKARYOTES

Five Kingdoms

“Crown species”

Monera

Protoctista

fungi

Animals pl

ants

1 23

4

5

4

1

2

3

5

The CellThe Cell

Prokaryotic Eukaryotic

AutofluorescenceAutofluorescence of algal and of algal and cyanobacterialcyanobacterial cellscells

Classification of Classification of phototrophicphototrophic organisms organisms in terms of energy and carbon sources. in terms of energy and carbon sources.

Types Types of of algal bodyalgal body

unicellular colonial filamentous

foliar tubular Blade-like, kelp

Leafy axis

Bold, HC and Wynne, MJ. Introduction to the algae, Prentice-Hall, Inc.New Jersey.

Sexual Sexual reproduction reproduction of of algae algae and and nonalgal plantsnonalgal plants

Uniting gametsgamets of a unicellular alga

Unicellular gametangiagametangiaof a filamentous alga

Multicellular gametangiumgametangium

ArchegoniumArchegonium(liverwort)

AntheridiumAntheridium(liverwort)

Bold, HC and Wynne, MJ. Introduction to the algae, Prentice-Hall, Inc.New Jersey.

Sexual Sexual reproductionreproduction

Isogamy (zygote)

Oogamy (oospore)

Conjugation (zygospore)

Bold, HC and Wynne, MJ. Introduction to the algae, Prentice-Hall, Inc.New Jersey.

Algal Algal life life cyclescycles

CyanobacteriaCyanobacteria

From: Margulis, L & Schwartz, K.V. 1998 Five Kingdoms. Freeman, NYStaley, J. T. et al 1989 Bergey’s manual of Systematic bacteriology. William & Wilkins, Baltimore

S external layer (slime)OM outer memebranePL peptidoglycan layerCM cytoplasmic membraneCW cell wallCY cytoplasmaE cell envelopeGV gas vesicle

N nucleoplasmic regionC carboxysomePP polyphosphate granuleCP cyanophycin granuleGG glycogen granulesTH thylakoidPB phycobilisome

CyanobacteriaCyanobacteria -- Form Form diversitydiversity

0.5 0.5 -- 6060 µmµm

PigmentsPigments

Cayanobacterial TaxonomyCayanobacterial Taxonomy: :

RippkaRippka et al. 1979et al. 1979

Group Group II

+

Gloeobacter

-

+

Gloeocapsa+

Gloeothece

+

-

Synechocystis-

Synechococcus

+

+

Chamaesiphon

+

ScheathScheathSlimeSlimeThylakoidsThylakoids

Binary fission in 2-3 planes

Binary fission in one plane

UnicellularUnicellularGloeothece PCC 6909

Merismopedia punctata

Chroococcus PCC 9340

Cyanothece PCC 7418

GroupGroup IIIIUnicellular, division in multiple planesUnicellular, division in multiple planes

Motile baeocytesMotile baeocytes,,PseudofilamentsPseudofilaments

Unmotile Unmotile baeocytesbaeocytes

Motile Motile baeocytesbaeocytes

PleurocapsaPleurocapsaXenococcusXenococcusStanieriaStanieria

Stanieria PCC 7301

Pleurocapsa

GroupGroup IIIIIIFilamentous, division in one plane

MotileMotile, , sheathsheath absent absent oror veryvery thinthin, , SpirulinaSpirulina

MotileMotile,, sheathsheath absentabsent or very thinor very thinOscillatoriaOscillatoria

Non Non motilemotile, , very thick sheathvery thick sheathLPP ALPP A

MotileMotile, , sheathsheath absent; absent; constrictionsconstrictions; polar gas ; polar gas vesiclesvesiclesPseudanabaenaPseudanabaena

MotileMotile and noand no--motilemotile, , withwith oror withoutwithout sheathsheathLPP BLPP B

Spirulina PCC 9445

Oscillatoria sp.

Lyngbya sp.

Phormidium sp.

Pseudanabaena PCC9716

GroupGroup IVIVFilamentous, withFilamentous, with heterocystsheterocysts and division in one and division in one

planeplaneHormo-gonia

Heterocysts and Akinets

Cell form Typical genera

Spherical or Spherical or ovaloval

AnabaenaHeterocystsHeterocystsintercalary or terminal, intercalary or terminal,

AkinetenAkineten changeablechangeable cylindricalcylindrical Nodularia

--

HeterocystsHeterocysts terminal, terminal, AkinetenAkineten next next to to heterocystsheterocysts

Isodiametric or Isodiametric or cylindricalcylindrical

Cylindrospermum

HeterocystsHeterocysts terminal, terminal, AkinetenAkineten several several in in the the rowrow

Spherical orSpherical orovaloval

Nostoc

HeterocystsHeterocystsintercalary intercalary

cylindricalcylindrical Scytonema

HeterocystsHeterocysts basalbasal cylindricalcylindrical Calothrix

++

GroupGroup VVFilamentous, with Filamentous, with heterocystsheterocysts, division in more than one , division in more than one

planeplane

Reproduction Hetero-cysts

Adult-stage Typical genera

Terminal or intercalary

Breakage of the trichome results in formation of Gloeocapsa-like aggregates, containing heterocysts, from which later hormogonia are created

ChlorogloeopsisChlorogloeopsis

Intercalary Trichoms with lateral branching from which later hormogonia are created

Fischerella Fischerella

Through breakage of the trichome, hormogonia or akinets

Stigonema

ProchloralesProchlorales((propro--primitiveprimitive, , chloroschloros--grgrüünn))

ProchlorococcusProchlorococcus

chlorophyll a und b, Phycobiliproteins

Prochloron (Lewin 1977)

Prochlorothrix (Burger-Wiersma et al. 1986)

Prochlorococcus (Chisholm et al.1992)

(5x104 - 2x105 Zellen ml-1)

PhylogenyPhylogenySequencing Sequencing of of several gene several gene fragments including: fragments including: 16S 16S rRNArRNA, , rpoC1rpoC1, , psbApsbA, , glnBglnB, , UreABCDEFGUreABCDEFG and and ITS approved the ITS approved the statement that statement that ProchlorococcusProchlorococcusemerges within the emerges within the ““classicalclassical””cyanobacteria cladecyanobacteria clade

No No phylogeneticphylogeneticuniformityuniformity in in ProchlorophytesProchlorophytes

Close phylogenetic relation with cyanobacteriaClose phylogenetic relation with cyanobacteria

Partensky et al. (1999)

Phylum Phylum ChlorophytaChlorophyta: : green algaegreen algae

Life Cycle of Chlamydomonas, a unicellular green algae

Sexual reproduction:

•fusion of identical cells (isogamy)

•fertilization of a large non-motile cell by a smaller motile one (oogamy).

Phylum Phylum ChlorophytaChlorophyta: green algae : green algae ("chlor" - green, "phyta" - plant).

•The most closely related to plants,

•Includes unicellular, colonial and multicellularforms.

•Inhabit aquatic (mostly freshwater) and damp terrestrial environments.

•Many of the simpler forms are symbionts, e.g. some lichens,

•Alternation between haploid (asexual) and diploid (sexual) multicellular generations.

Phylum Phylum BacilariophytaBacilariophyta: the diatoms: the diatoms(" a little stick plant") -

•Unicellular aquatic forms, some of the most abundant protistan plant organisms in the oceans

•shells of SiO2.

•Cells comprised of two separate valves (shells).

Diatomaceous earth—dead diatoms settle to seafloor, collected and used in abrasives

Plankton—abundant food source for marine organisms

Reproduction: vegetative and sexual (auxospore)

Diatoms are traditionally divided Diatoms are traditionally divided into two orders:into two orders:

Centric diatoms (Centrales), which are radially symmetric

Pennate diatoms (Pennales), which are bilaterally symmetric.

Phylum Phylum PhaeophytaPhaeophyta: brown algae: brown algae("("phaeophaeo" " -- brown, "brown, "phytaphyta" " -- plant).plant).

Multicellular, mostly marine

Underwater forests—habitats

Most contain the pigment fucoxanthin, responsible for the distinctive greenish-brown color

Kelp—food, habitats for aquatic organisms

Reproduce by means of flagellate spores

Of commercial importance to humans (Pectin, alginin)

Phylum Phylum RhodophytaRhodophyta: red algae : red algae ("("rhodrhod" " -- red, "red, "phytaphyta" " -- plant).plant).

Mostly multicellular,marine,

Most of the coralline algae, which secrete calcium carbonateand play a major role in building coral reefs,

Commercial importance : Agar, carrageen, sushi

Sexual reproduction: non-motile larger female and smaller male gametes

Phylum Phylum PyrrophytaPyrrophyta: the : the dinoflagellatesdinoflagellatesFlagellate protists with two dissimilar flagella(longitudinal and transverse), mostly in marine plankton

Most are unicellular forms

About half of all are photosynthetic

Some species, called zooxanthellae, are endosymbionts of marine animals and protozoa (coral reefs).

Colorless predators on other protozoa, and a few forms are parasitic (e.g. Oodinium, Pfisteria).

Some are bioluminescent

Red tide—population explosion of certain types of dinoflagellates. Kills large amounts of fish. Depletes water of oxygen and releases toxins into the water.

Reproduction: vegetative through fission or sexual